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Sample records for praseodymium holmium erbium

  1. Discovery of dysprosium, holmium, erbium, thulium, and ytterbium isotopes

    SciTech Connect

    Fry, C.; Thoennessen, M.

    2013-09-15

    Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  2. Combination of erbium and holmium laser radiation for tissue ablation

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans S.; Frenz, Martin; Koenz, Flurin; Altermatt, Hans J.; Weber, Heinz P.

    1996-05-01

    Erbium lasers emitting at 2.94 micrometers and holmium lasers emitting at 2.1 micrometers are interesting tools for cutting, drilling, smoothing and welding of water containing tissues. The high absorption coefficient of water at these wavelengths leads to their good ablation efficiency with controlled thermally altered zones around the ablation sites. Combination of pulses with both wavelengths transmitted through one fiber were used to perform incisions in soft tissue and impacts in bone disks. Histological results and scanning electron microscope evaluations reveal the strong influence of the absorption coefficient on tissue effects, especially on the ablation efficiency and the zone of thermally damaged tissue. It is demonstrated that the combination of high ablation rates and deep coagulation zones can be achieved. The results indicate that this laser system can be considered as a first step towards a multi-functional medical instrument.

  3. Combination of fiber-guided pulsed erbium and holmium laser radiation for tissue ablation under water

    NASA Astrophysics Data System (ADS)

    Pratisto, Hans; Frenz, Martin; Ith, Michael; Altermatt, Hans J.; Jansen, E. Duco; Weber, Heinz P.

    1996-07-01

    Because of the high absorption of near-infrared laser radiation in biological tissue, erbium lasers and holmium lasers emitting at 3 and 2 mu m, respectively, have been proven to have optimal qualities for cutting or welding and coagulating tissue. To combine the advantages of both wavelengths, we realized a multiwavelength laser system by simultaneously guiding erbium and holmium laser radiation by means of a single zirconium fluoride (ZrF4) fiber. Laser-induced channel formation in water and poly(acrylamide) gel was investigated by the use of a time-resolved flash-photography setup, while pressure transients were recorded simultaneously with a needle hydrophone. The shapes and depths of vapor channels produced in water and in a submerged gel after single erbium and after combination erbium-holmium radiation delivered by means of a 400- mu m ZrF4 fiber were measured. Transmission measurements were performed to determine the amount of pulse energy available for tissue ablation. The effects of laser wavelength and the delay time between pulses of different wavelengths on the photomechanical and photothermal responses of meniscal tissue were evaluated in vitro by the use of histology. It was observed that the use of a short (200- mu s, 100-mJ) holmium laser pulse as a prepulse to generate a vapor bubble through which the ablating erbium laser pulse can be transmitted (delay time, 100 mu s) increases the cutting depth in meniscus from 450 to 1120 mu m as compared with the depth following a single erbium pulse. The results indicate that a combination of erbium and holmium laser radiation precisely and efficiently cuts tissue under water with 20-50- mu m collateral tissue damage. wave, cavitation, channel formation, infrared-fiber-delivery system, tissue damage, cartilage.

  4. Effects of simultaneously fiber transmitted erbium and holmium radiation on the interaction with highly absorbing media

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Pratisto, Hans S.; Ith, Michael; Koenz, Flurin; Weber, Heinz P.

    1995-05-01

    Erbium and Holmium lasers have both been shown to be suitable for orthopedic surgery performed under water. Erbium lasers emitting in the 3 micrometers wavelength region corresponding to the maximum water absorption peak effectively ablated biological tissues with high precision and minimal thermal damage. Holmium laser radiation at 2 micrometers , due to a lower absorption coefficient, is characterized by a greater extent of thermal damage leading to hemostasis. To combine the special advantages of each system we simultaneously coupled their radiation into a zirconium fluoride fiber (ZrF4) which was protected with a quartz fiber tip. Pressure measurements performed in the liquid using a piezo electrical transducer, transmission measurements and video flash lamp schlieren imaging of the laser induced vapor bubble were used in order to determine optimum laser parameters. The cutting efficiency of the Erbium laser is drastically improved when a low energy Holmium laser pulse is additionally used which is just able to open a vapor channel through which the Erbium laser pulse can be transmitted. The dynamics of the channel formation, geometry and life time are measured as a function of the delay time between the two different laser pulses and the pulse energy applied. The combination of 2 micrometers and 3 micrometers radiation seems to be an ideal instrument for tissue treatment.

  5. Effect of holmium and erbium laser action on the human lens: an in-vitro study

    NASA Astrophysics Data System (ADS)

    Kasprzak, Jan; Kecik, Dariusz

    1997-10-01

    We investigated the holmium and erbium lasers operating at the medium IR range, used for cataract surgery. The main advantage of these lasers action on biological structures is total absorption of radiation by superficial layers. During the study of the lens emulsification process we found that the mechanical properties of the lens nucleus were of crucial importance for the rate of emulsification. The soft lenses were fragmented and emulsified after 200-700 pulses, while the hard lens required 5000 or more pulses while complete emulsification was not achieved. The results are promising and show that the holmium and erbium lasers can be used for human lens emulsification during ECCE. For clinical purposes, however, it is necessary to construct a suitable fiberoptic tip to be used in cataract removal. It seems that lasers whose beam is in the medium IR range could be used in many ophthalmic operations.

  6. Erbium:YAG and holmium:YAG laser root resection of extracted human teeth.

    PubMed

    Komori, T; Yokoyama, K; Matsumoto, Y; Matsumoto, K

    1997-02-01

    Root resection of extracted human teeth was performed using the erbium:YAG (Er:YAG) and holmium:YAG (Ho:YAG) laser to investigate the clinical application of lasers on hard tissue. The CO2 laser and the mechanical drill were also used for comparison. After resection using these technologies, the morphological changes of the cut surface were investigated by optical and scanning electron microscope. Er:YAG laser irradiation produced smooth, clean resected surfaces without signs of thermal damages. Complete obturation of the root canal was maintained after Er:YAG laser irradiation. Ho:YAG laser irradiation, however, produced some signs of thermal damage. Relatively large voids between the gutta-percha and the canal walls were revealed after Ho:YAG laser irradiation. The sealing of the dentinal tubules was not completely attained as stipulated by original conditions of this study. PMID:9467336

  7. Influence of pulse duration on erbium and holmium laser ablation under water

    NASA Astrophysics Data System (ADS)

    Ith, Michael; Frenz, Martin; Pratisto, Hans S.; Weber, Heinz P.; Altermatt, Hans J.; Staeubli, Hans U.; Asshauer, Thomas; Delacretaz, Guy P.; Salathe, Rene-Paul; Gerber, Bruno E.

    1995-01-01

    Erbium and Holmium lasers are ideally suited for cutting and drilling biological tissue. This is due to the fact that their wavelengths (Er:YSGG at 2.79 micrometers and Ho:YAG at 2.12 micrometers ) are strongly absorbed in water which is present in all tissues. Combined with an optical fiber these lasers seem to be optimal instruments for endoscopic and/or minimal invasive applications in surgery. In this study we focused our interest on cutting of human meniscus in the knee where, besides a very limited operation field, the standard arthroscopic treatment is performed in a liquid, highly absorbing environment. The bubble formation process, therefore, has to be well understood because it mainly determines relevant aspects of tissue ablation. The influence of the laser parameters in general and the influence of pulse duration in particular are determined in this paper for two different laser wavelengths. The goal was to determine the optimum laser parameters in view of a high ablation efficiency, a high precision and a minimal destruction of the adjacent tissue. To determine the optimum pulse duration for ablating tissue under water and to obtain a better understanding of the channel formation process, transmission and pressure measurements together with video flash photography were performed. Additionally, we determined experimentally the ratio between initial laser pulse energy and energy available for tissue treatment under water. To prove the results obtained, cuts in human meniscus were performed, sectioned and evaluated. The comparison between the results obtained with the Erbium and Holmium laser revealed a strong influence of the absorption coefficients on the tissue effects, especially on the ablation efficiency and on the zone of thermally and mechanically damaged tissue.

  8. Histologic comparison of needle, holmium:YAG, and erbium:YAG endoscopic goniotomy

    NASA Astrophysics Data System (ADS)

    Joos, Karen M.; Shen, Jin-Hui; Rivera, Brian K.; Hernandez, Eleut; Shetlar, Debra J.

    1995-05-01

    An endoscope allows visualization of the anterior chamber angle in porcine eyes despite the presence of cloudy corneas. The pectinate ligaments in the anterior chamber angle are a surgical model for primary infantile glaucoma. This study investigated the histologic results, one month after treating the anterior chamber angle with a goniotomy needle, the holmium:YAG laser, or the erbium:YAG laser coupled to a small endoscope. The anterior chambers were deepened with a viscoelastic material in one-month-old anesthetized pigs. An Olympus 0.8 mm diameter flexible endoscope was externally coupled to a 23 gauge needle or a 300 micron diameter fiber. The angle was treated for 120 degrees by one of the three methods, and the probe was removed. During the acute study, all three methods cut the pectinate ligaments. The histologic findings one month after healing demonstrated minimal surrounding tissue damage following goniotomy with a needle and the most surrounding tissue damage following treatment with the holmium:YAG laser.

  9. Excitation functions for the helium-ion-induced fission of holmium and erbium

    SciTech Connect

    Iyer, R.H.; Pandey, A.K.; Kalsi, P.C.; Sharma, R.C. )

    1991-12-01

    Excitation functions for the helium-ion-induced fission of holmium ({ital Z}=67) and erbium ({ital Z}=68) in the energy range 34--70 MeV were measured using lexan polycarbonate plastic as the fission fragment track detector. By analyzing the data in terms of the statistical model expression for {Gamma}{sub {ital f}}/{Gamma}{sub {ital n}}, the ratio of the fission width to neutron emission width, the fission barriers of the compound nuclei {sup 1}{sub 69}{sup 69}Tm and {sup 17}{sub 70}{sup 1.3}Yb were determined to be 29.8{plus minus}3 and 27.8{plus minus}3 MeV, respectively. The corresponding values for the fission level density parameter were found to be {ital a}{sub {ital f}}={ital A}/12 and {ital A}/13, respectively. The uncertainties shown in the fission barriers allow for inclusion of other values derived from reasonable upper and lower limits of {ital a}{sub {ital f}} values of {ital A}/8 to {ital A}/20. The measured fission barriers compare very well with the shell-corrected liquid-drop barriers of Myers and Swiatecki. The present measurements extend the range of low-{ital Z} elements which are away from the closed-shell region and which are studied at these medium energies. The results are compared with similar data available in the literature which bring out some interesting correlations and trends in the fission properties, viz., fission barriers and level density parameters of low-{ital Z} elements.

  10. Self-quenching of luminescence in concentrated lithium--erbium and lithium--holmium double fluoride crystals

    SciTech Connect

    Tkachuk, A.M.; Klokishner, S.I.; Petrov, M.V.

    1985-10-01

    For the radiative terms of holmium and erbium ions in concentrated LiErF/sub 4/ and LiHoF/sub 4/ crystals, numerical estimates were made of the microparameters and transfer rates on the basis of known experimental data on the structure of luminescence centers, probabilities of intracenter transitions, phonon spectrum of the crystals, and electron--phonon interaction. The schemes of the most important processes of cross-relaxation quenching and nonlinear (in excitation intensity) interaction have been determined. On the basis of an analysis of numerical values of the rates of intracenter relaxation and interionic transfer of energy, conclusions are reached concerning the processes which significantly affect the radiative characteristics of concentrated crystals. The role of the processes of cross-relaxation quenching and nonlinear interaction in the formation of an inverse population of excited multiplets and the influences of these processes on the characteristics of stimulated emission are discussed.

  11. Expanding rare-earth oxidation state chemistry to molecular complexes of holmium(II) and erbium(II).

    PubMed

    MacDonald, Matthew R; Bates, Jefferson E; Fieser, Megan E; Ziller, Joseph W; Furche, Filipp; Evans, William J

    2012-05-23

    The first molecular complexes of holmium and erbium in the +2 oxidation state have been generated by reducing Cp'(3)Ln [Cp' = C(5)H(4)SiMe(3); Ln = Ho (1), Er (2)] with KC(8) in the presence of 18-crown-6 in Et(2)O at -35 °C under argon. Purification and crystallization below -35 °C gave isomorphous [(18-crown-6)K][Cp'(3)Ln] [Ln = Ho (3), Er (4)]. The three Cp' ring centroids define a trigonal-planar geometry around each metal ion that is not perturbed by the location of the potassium crown cation near one ring with K-C(Cp') distances of 3.053(8)-3.078(2) Å. The metrical parameters of the three rings are indistinguishable within the error limits. In contrast to Ln(2+) complexes of Eu, Yb, Sm, Tm, Dy, and Nd, 3 and 4 have average Ln-(Cp' ring centroid) distances only 0.029 and 0.021 Å longer than those of the Ln(3+) analogues 1 and 2, a result similar to that previously reported for the 4d(1) Y(2+) complex [(18-crown-6)K][Cp'(3)Y] (5) and the 5d(1) La(2+) complex [K(18-crown-6)(Et(2)O)][Cp″(3)La] [Cp″ = 1,3-(Me(3)Si)(2)C(5)H(3)]. Surprisingly, the UV-vis spectra of 3 and 4 are also very similar to that of 5 with two broad absorptions in the visible region, suggesting that 3-5 have similar electron configurations. Density functional theory calculations on the Ho(2+) and Er(2+) species yielded HOMOs that are largely 5d(z(2)) in character and supportive of 4f(10)5d(1) and 4f(11)5d(1) ground-state configurations, respectively. PMID:22583320

  12. Semiempirical quantum chemistry model for the lanthanides: RM1 (Recife Model 1) parameters for dysprosium, holmium and erbium.

    PubMed

    Filho, Manoel A M; Dutra, José Diogo L; Rocha, Gerd B; Simas, Alfredo M; Freire, Ricardo O

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes' coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 Å, for the sparkle models, to 0.04 Å for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models. PMID:24497945

  13. Semiempirical Quantum Chemistry Model for the Lanthanides: RM1 (Recife Model 1) Parameters for Dysprosium, Holmium and Erbium

    PubMed Central

    Filho, Manoel A. M.; Dutra, José Diogo L.; Rocha, Gerd B.; Simas, Alfredo M.; Freire, Ricardo O.

    2014-01-01

    Complexes of dysprosium, holmium, and erbium find many applications as single-molecule magnets, as contrast agents for magnetic resonance imaging, as anti-cancer agents, in optical telecommunications, etc. Therefore, the development of tools that can be proven helpful to complex design is presently an active area of research. In this article, we advance a major improvement to the semiempirical description of lanthanide complexes: the Recife Model 1, RM1, model for the lanthanides, parameterized for the trications of Dy, Ho, and Er. By representing such lanthanide in the RM1 calculation as a three-electron atom with a set of 5 d, 6 s, and 6 p semiempirical orbitals, the accuracy of the previous sparkle models, mainly concentrated on lanthanide-oxygen and lanthanide-nitrogen distances, is extended to other types of bonds in the trication complexes’ coordination polyhedra, such as lanthanide-carbon, lanthanide-chlorine, etc. This is even more important as, for example, lanthanide-carbon atom distances in the coordination polyhedra of the complexes comprise about 30% of all distances for all complexes of Dy, Ho, and Er considered. Our results indicate that the average unsigned mean error for the lanthanide-carbon distances dropped from an average of 0.30 Å, for the sparkle models, to 0.04 Å for the RM1 model for the lanthanides; for a total of 509 such distances for the set of all Dy, Ho, and Er complexes considered. A similar behavior took place for the other distances as well, such as lanthanide-chlorine, lanthanide-bromine, lanthanide, phosphorus and lanthanide-sulfur. Thus, the RM1 model for the lanthanides, being advanced in this article, broadens the range of application of semiempirical models to lanthanide complexes by including comprehensively many other types of bonds not adequately described by the previous models. PMID:24497945

  14. High-power frequency comb in the range of 2-2.15  μm based on a holmium fiber amplifier seeded by wavelength-shifted Raman solitons from an erbium-fiber laser.

    PubMed

    Coluccelli, Nicola; Cassinerio, Marco; Gambetta, Alessio; Laporta, Paolo; Galzerano, Gianluca

    2014-03-15

    We demonstrate a room-temperature high-power frequency comb source covering the spectral region from 2 to 2.15 μm. The source is based on a femtosecond erbium-fiber laser operating at 1.55 μm with a repetition rate of 250 MHz, wavelength-shifted up to 2.06 μm by the solitonic Raman effect, seeding a large-mode-area holmium (Ho) fiber amplifier pumped by a thulium (Tm) fiber laser emitting at 1.94 μm. The frequency comb has an integrated power of 2 W, with overall power fluctuations as low as 0.3%. The beatnote between the comb and a high-spectral-purity, single-frequency Tm-Ho laser has a linewidth of 32 kHz over 1 ms observation time, with a signal-to-noise ratio in excess of 30 dB. PMID:24690863

  15. Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of (161)Er and (160)Er medical isotopes.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Baba, M

    2016-09-01

    Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of (161)Er, (160)Er and (1)(59,157)Dy. For comparison of the production routes of medically related (161)Er and (160)Er radioisotopes new experimental cross section data were deduced for the (162)Er(p,x)(161,160)Er and (162)Er(d,x)(161,160)Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015. PMID:27451109

  16. Holmium laser pumped with a neodymium laser

    SciTech Connect

    Bowman, S.R.; Rabinovich, W.S.

    1991-07-30

    This patent describes a solid-state laser device. It comprises a holmium laser having a first host material doped with an amount of holmium ions sufficient to produce an output laser emission at about 3 {mu}m when the holmium ions in the holmium laser are pumped by a pump beam at a wavelength of about 1.1 {mu}m; and neodymium laser pump source means for supplying a pump beam to pump the holmium ions in the holmium laser at a wavelength of about 1.1 {mu}m.

  17. Metals fact sheet: Holmium/thulium

    SciTech Connect

    1996-02-01

    This article discusses the geology, exploitation, market, and applications of holmium and thulium. Holmium and thulium are important part in the development of specific laser technologies, x-ray film and high-temperature superconductors.

  18. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters.

    PubMed

    Prasai, K; Alves, E; Bagliani, D; Basak Yanardag, S; Biasotti, M; Galeazzi, M; Gatti, F; Ribeiro Gomes, M; Rocha, J; Uprety, Y

    2013-08-01

    In a microcalorimetric neutrino mass experiment using the radioactive decay of (163)Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the (163)Ho fabrication), in the temperature range 70 mK-300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment. PMID:24007077

  19. Thermal properties of holmium-implanted gold films for a neutrino mass experiment with cryogenic microcalorimeters

    SciTech Connect

    Prasai, K.; Yanardag, S. Basak; Galeazzi, M.; Uprety, Y.; Alves, E.; Rocha, J.; Bagliani, D.; Biasotti, M.; Gatti, F.; Gomes, M. Ribeiro

    2013-08-15

    In a microcalorimetric neutrino mass experiment using the radioactive decay of {sup 163}Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the {sup 163}Ho fabrication), in the temperature range 70 mK–300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment.

  20. Magnetic structure of holmium

    NASA Astrophysics Data System (ADS)

    Pechan, M. J.; Stassis, C.

    1984-03-01

    The magnetic structure of high purity single crystals of holmium has been studied by neutron diffraction techniques. Although the general characteristics of the magnetic structure have been found to agree with earlier measurements, some discrepancies have been resolved and new features have been observed. The magnetic form factor has been measured and compared with relativistic atomic calculations. The low temperature structure (T<20 K) is that of a conical ferromagnet with wave vector (1/6)(2π/c) along the c axis. The basal plane moment is 9.7 μB and the c-axis ferromagnetic component is 1.6 μB at T=6 K. Bunching of the basal plane moments around the easy hexagonal direction has been observed below T=50 K. Evidence for asphericity in the magnetization density is presented and discussed. The wave vector of the basal plane modulation decreases monotonically with temperature in general accordance with the Elliott-Wedgewood theory. Several inflection points were observed, however, which correspond to commensurability with the chemical lattice. The measured temperature dependence of the c- and a-axis lattice constants shows significant magnetostriction. The possibility of a c-axis modulated moment is discussed.

  1. Erbium laser in gynecology.

    PubMed

    Vizintin, Z; Lukac, M; Kazic, M; Tettamanti, M

    2015-10-01

    The aim of this paper is to present a novel laser technology utilizing the erbium YAG laser for various minimally invasive, non-surgical procedures in gynecology. Non-ablative, thermal-only SMOOTH-mode erbium pulses are used to produce vaginal collagen hyperthermia, followed by collagen remodeling and the synthesis of new collagen fibers, resulting in improved vaginal tissue tightness and elasticity. This erbium laser technology is used for treatments of vaginal laxity, stress urinary incontinence, pelvic organ prolapse and vaginal atrophy. In the period from 2010 to 2014, several clinical studies covering all four indications were conducted with the aim to prove the efficacy and safety of this novel technology. An overview is presented of the results of these studies where several objective as well as subjective assessment tools were used. The results have shown that SMOOTH-mode erbium laser seems to be an effective and safe method for treating vaginal laxity, stress urinary incontinence, pelvic organ prolapses and vaginal atrophy. PMID:26366793

  2. Erbium diffusion in silicon dioxide

    SciTech Connect

    Lu Yingwei; Julsgaard, B.; Petersen, M. Christian; Jensen, R. V. Skougaard; Pedersen, T. Garm; Pedersen, K.; Larsen, A. Nylandsted

    2010-10-04

    Erbium diffusion in silicon dioxide layers prepared by magnetron sputtering, chemical vapor deposition, and thermal growth has been investigated by secondary ion mass spectrometry, and diffusion coefficients have been extracted from simulations based on Fick's second law of diffusion. Erbium diffusion in magnetron sputtered silicon dioxide from buried erbium distributions has in particular been studied, and in this case a simple Arrhenius law can describe the diffusivity with an activation energy of 5.3{+-}0.1 eV. Within a factor of two, the erbium diffusion coefficients at a given temperature are identical for all investigated matrices.

  3. Erbium hydride decomposition kinetics.

    SciTech Connect

    Ferrizz, Robert Matthew

    2006-11-01

    Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report are analyzed quantitatively using Redhead's method to yield kinetic parameters (E{sub A} {approx} 54.2 kcal/mol), which are then utilized to predict hydrogen outgassing in vacuum for a variety of thermal treatments. Interestingly, it was found that the activation energy for desorption can vary by more than 7 kcal/mol (0.30 eV) for seemingly similar samples. In addition, small amounts of less-stable hydrogen were observed for all erbium dihydride films. A detailed explanation of several approaches for analyzing thermal desorption spectra to obtain kinetic information is included as an appendix.

  4. SESAM mode-locked red praseodymium laser.

    PubMed

    Gaponenko, Maxim; Metz, Philip Werner; Härkönen, Antti; Heuer, Alexander; Leinonen, Tomi; Guina, Mircea; Südmeyer, Thomas; Huber, Günter; Kränkel, Christian

    2014-12-15

    We present the first semiconductor saturable absorber mirror (SESAM) mode-locked praseodymium solid-state laser. The laser is based on a Pr(3+):LiYF(4) crystal as gain medium and a GaInP-quantum well-based SESAM. Self-starting continuous-wave mode-locked laser operation with an average output power of 16 mW is achieved at a center wavelength of 639.5 nm. The laser operates at a repetition rate of ∼85.55  MHz and emits pulses with a duration of ∼18  ps. PMID:25503035

  5. Thermal Properties of Holmium-Implanted Gold Films

    NASA Astrophysics Data System (ADS)

    Prasai, K.; Alves, E.; Bagliani, D.; Yanardag, S. Basak; Biasotti, M.; Galeazzi, M.; Gatti, F.; Gomes, M. Ribeiro; Rocha, J.; Uprety, Y.

    2014-09-01

    The effective mass of the electron neutrino can be probed by studying the Ho electron capture decay with cryogenic microcalorimeters. The goal is to perform a calorimetric experiment, where all the energy released in the decay is measured except for the kinetic energy of the neutrino. To achieve such a goal, multiple approaches are being investigated to enclose the radioactive source in a microcalorimeter absorber without affecting the thermal properties of the absorber material. One such approach is to implant the radioactive isotope into a gold absorber, as gold is successfully used in similar applications. We measured the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the Ho fabrication), in the temperature range 70-300 mK. Our results show that the specific heat capacity of the films is not affected by the implant, making this a viable option for a future experiment. We also verified that the implant does not affect the crystal structure of the gold film.

  6. Non-radiative decay of holmium-doped laser materials

    NASA Astrophysics Data System (ADS)

    Bowman, Steven R.; O'Connor, Shawn; Condon, Nicholas J.; Friebele, E. Joseph; Kim, Woohong; Shaw, B.; Quimby, R. S.

    2013-03-01

    Anti-Stokes fluorescence cooling has been demonstrated in a number rare earth doped materials. Ytterbium doped oxides and fluorides, such as ZBLAN, YLF, and YAG, were the first materials to exhibit cooling.1,2,3 These materials were originally developed as laser gain media and fluorescence cooling was eventually incorporated into the 1μm lasers to reduce detrimental thermal loading.4 Anti-Stokes cooling can offset quantum defect heating allowing laser power to be scaled to very high average powers. Since the early work in ytterbium, fluorescence cooling has been demonstrated in both erbium and thulium doped materials.5,6 These materials were also initially developed as lasing media and their fluorescence cooling could be used to increase laser powers at 1.5μm and 2.0μm. In this study we examine the radiative efficiency of holmium and ask the question, "Can anti-Stokes fluorescence cooling be extended beyond 2μm?"

  7. Electronic and optical properties of Praseodymium trifluoride

    SciTech Connect

    Saini, Sapan Mohan

    2014-10-24

    We report the role of f- states on electronic and optical properties of Praseodymium trifluoride (PrF{sub 3}) compound. Full potential linearized augmented plane wave (FPLAPW) method with the inclusion of spin orbit coupling has been used. We employed the local spin density approximation (LSDA) and Coulomb-corrected local spin density approximation (LSDA+U). LSDA+U is known for treating the highly correlated 4f electrons properly. Our theoretical investigation shows that LSDA+U approximation reproduce the correct insulating ground state of PrF{sub 3}. On the other hand there is no significant difference of reflectivity calculated by LSDA and LSDA+U. We find that the reflectivity for PrF{sub 3} compound stays low till around 7 eV which is consistent with their large energy gaps. Our calculated reflectivity compares well with the experimental data. The results are analyzed in the light of transitions involved.

  8. Early complications with the holmium laser

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Stewart, Steven C.; Ruckle, Herbert C.; Poon, Michael W.

    1997-05-01

    The purpose of this study is to report early complications in our initial experience with the holmium laser in 133 patients. A retrospective study of patients undergoing endourological procedures with the holmium laser was performed. Complications included urinary tract infection (3), post-operative bradycardia (1), inverted T-waves (1), intractable flank pain (1), urinary retention (1), inability to access a lower pole calyx with a 365 micron fiber (9), stone migration (5), termination of procedure due to poor visualization (2). No ureteral perforations or strictures occurred. The holmium laser was capable of fragmenting all urinary calculi in this study. In our initial experience, the holmium laser is safe and effective in the treatment of genitourinary pathology. Use of laser fibers larger than 200 microns occasionally limit deflection into a lower pole or dependent calyx.

  9. Texture evolution and infrared optical properties of praseodymium fluoride films

    NASA Astrophysics Data System (ADS)

    Su, Wei-Tao; Li, Bin; Liu, Ding-Quan; Zhang, Feng-Shan

    2007-10-01

    Praseodymium fluoride (PrF3) thin films were deposited on Ge(1 1 1) and zinc selenide substrates by molybdenum boat evaporation method. The crystal structures of thin film were characterized using XRD technique and the texture coefficients were calculated. The texture of praseodymium fluoride films changes from (3 0 2) to (1 1 0) texture when the temperature increases from 100 °C to 250 °C. Drastic tensile stress makes all the films covered by a network of fine cracks with width of nanometer-scale. The infrared transmission spectrum was measured to investigate the optical properties for all the films. The optical constants of praseodymium fluoride film were determined by using Lorentz oscillator model in the range from 8000 cm-1 to 500 cm-1.

  10. The effective thermal conductivity of an adsorbent - Praseodymium cerium oxide

    NASA Technical Reports Server (NTRS)

    Secary, J. J.; Tong, T. W.

    1992-01-01

    The results of an experimental study to determine the effective thermal conductivity of praseodymium cerium oxide are reported. Praseodymium cerium oxide is an adsorbent used in the development of adsorption compressors for spaceborne refrigeration systems. A guarded-hot-plate apparatus was built for this study. Measurements were carried out for mean temperatures ranging from 300 to 600 C under a vacuum of 10 exp -5 torr. For the temperature range studied, the effective thermal conductivity increased from 0.14 to 0.76 W/m per C with increasing temperature, while displaying a cubic temperature dependency.

  11. Optical characterization of ZnO nanomaterial with praseodymium ions

    NASA Astrophysics Data System (ADS)

    Sharma, Y. K.; Pal, Sudha; Goyal, Priyanka; Bind, Umesh Chandra

    2016-05-01

    ZnO nanomaterial with praseodymium ions was prepared by chemical synthesis method. The ZnO nanomaterial was characterized by XRD, SEM and TEM. Their absorption in UV-VIS/NIR regions was measured at room temperature. The experimental oscillator strengths were calculated from the areas under the absorption bands. Eight absorption bands have been observed. From these spectral data various energy interaction parameters like Slater-Condon, Lande, Racah, Nephelauxetic ratio and bonding parameters have been computed. Judd-Ofelt analysis has been carried out using the absorption spectra to evaluate the radiative properties for luminescent levels of the praseodymium ion and discussed. The observed nano particle size is 2nm.

  12. Holmium:YAG surgical lasers.

    PubMed

    1995-03-01

    "Holmium:YAG (Ho:YAG)" is the shorthand name for a family of solid-state lasers that use the doping element holmium in a laser crystal (e.g., YAG [yttrium-aluminum-garnet]) and that emit energy at approximately 2.1 microns. This wavelength is relatively new to medicine and has been used in laser surgery for only about the last six years. Like the carbon dioxide (CO2) laser when it was first used clinically, the Ho:YAG laser is poised for rapid and wide-spread use. Ho:YAG lasers, like CO2 lasers, offer precise cutting with minimal damage to adjacent tissue; however, unlike CO2 lasers, they also offer fiberoptic delivery (which is ideal for endoscopic use) and the ability to treat tissue in a liquid-filled environment (e.g., saline, blood). The initial specialty for which the Ho:YAG laser was used was arthroscopic surgery, especially diskectomy. Today, it is effectively used in many surgical specialties, including general surgery, urology, laparoscopy, neurosurgery, lithotripsy, angioplasty, orthopedic surgery (which includes procedures such as meniscectomy, bone sculpting [may also be performed in plastic surgery], and some experimental surgery, such as cartilage shrinking to tighten loose joints), and dentistry. Because of its broad range of potential applications, it has been called the "Swiss Army Knife" of lasers. High-powered Ho:YAG lasers, which enable surgeons to work more quickly and cut more smoothly, have been made available only within the last three years (units offering > 20 W) to 18 months (units offering > 60 W). Because of this rapid increase, high-powered units are still relatively expensive, and it is not yet clear whether maximum power outputs will continue to increase or whether the cost of higher-power units will begin to come down. Although low-power and high-power Ho:YAG lasers can be used for the same procedures, their different ranges of possible clinical techniques make them better suited to different applications: low-power units are

  13. Yttrium and rare earth stabilized fast reactor metal fuel

    SciTech Connect

    Guon, J.; Grantham, L.F.; Specht, E.R.

    1992-05-12

    This patent describes an improved metal alloy reactor fuel consisting essentially of uranium, plutonium, and at least one element from the group consisting of yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

  14. Electron-impact excitation of holmium atoms

    SciTech Connect

    Smirnov, Yu M

    2000-06-30

    The electron-impact excitation of holmium atoms was studied by the method of extended crossing beams. The cross sections and the optical excitation functions were obtained for odd levels of Ho I, including the 22014 cm{sup -1} laser level. Over 99% of the atoms were shown to reside in the ground level prior to collisions with electrons. Also measured were the excitation cross sections for six even levels, which presumably participate in the formation of inversion population in a gas-discharge holmium vapour laser. (laser applications and other topics in quantum electronics)

  15. Spectrum of the holmium atom arising from bombardment of a tantalum surface by holmium ions

    SciTech Connect

    Vasileva, E.K.; Morozov, S.N.

    1986-12-01

    The ion--photon emission spectrum of holmium has been recorded and investigated. It is shown that the appearance of so-called continuous radiation (CR) is due to excitation of the lower triplet system of terms.

  16. Synthesis of phase pure praseodymium barium copper iron oxide.

    PubMed

    Konne, Joshua L; Davis, Sean A; Glatzel, Stefan; Hall, Simon R

    2013-06-18

    The control of crystallization of praseodymium barium copper iron oxide, an intermediate temperature solid oxide fuel cell cathode material, has been demonstrated for the first time using a biotemplated sol-gel synthesis technique. The results obtained showed significant improvement in purity, synthesis time, surface area and simplicity over that previously reported. PMID:23660963

  17. Energy transfer between thulium and praseodymium ions in solids

    SciTech Connect

    Cockroft, N.J.; Murdoch, K.M.

    1993-09-01

    New thulium-to-praseodymium upconversion and cross-relaxation energy transfer mechanisms are observed. YLiF{sub 4} has several subsets of dopant ions, which exhibit a variety of transfer efficiencies. Dual-pulse laser excitation of dimers in CsCdBr{sub 3} is used to demonstrate a probable upconversion pathway.

  18. Discovery of cesium, lanthanum, praseodymium and promethium isotopes

    SciTech Connect

    May, E.; Thoennessen, M.

    2012-09-15

    Currently, forty-one cesium, thirty-five lanthanum, thirty-two praseodymium, and thirty-one promethium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  19. DNA based materials doped with praseodymium (III) hydroxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Lazar, Cosmina Andreea; Kajzar, François; Mihaly, Maria; Pirvu, Cristian; Petcu, Adina Roxana; Olteanu, Nicoleta Liliana; Rau, Ileana

    2016-06-01

    Lanthanide ions have attracted intense research interest for their luminescence properties, which make them interesting for applications such as bioactive probes for magnetic resonance and luminescence. We present here our study related to the interaction between DNA-CTMA (hexadecyltrimethylammonium chloride) and praseodymium. The new materials synthesized were investigated from photophysical properties and morphological point of view.

  20. Holmium laser lithotripsy of bladder calculi

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Poon, Michael W.

    1998-07-01

    Although the overall incidence of bladder calculi has been decreasing, it is still a significant disease affecting adults and children. Prior treatment options have included open cystolitholapaxy, blind lithotripsy, extracorporeal shock wave lithotripsy, and visual lithotripsy with ultrasonic or electrohydraulic probes. The holmium laser has been found to be extremely effective in the treatment of upper tract calculi. This technology has also been applied to the treatment of bladder calculi. We report our experience with the holmium laser in the treatment of bladder calculi. Twenty- five patients over a year and a half had their bladder calculi treated with the Holmium laser. This study was retrospective in nature. Patient demographics, stone burden, and intraoperative and post-operative complications were noted. The mean stone burden was 31 mm with a range of 10 to 60 mm. Preoperative diagnosis was made with either an ultrasound, plain film of the abdomen or intravenous pyelogram. Cystoscopy was then performed to confirm the presence and determine the size of the stone. The patients were then taken to the operating room and given a regional or general anesthetic. A rigid cystoscope was placed into the bladder and the bladder stone was then vaporized using the holmium laser. Remaining fragments were washed out. Adjunctive procedures were performed on 10 patients. These included transurethral resection of the prostate, transurethral incision of the prostate, optic internal urethrotomy, and incision of ureteroceles. No major complications occurred and all patients were rendered stone free. We conclude that the Holmium laser is an effective and safe modality for the treatment of bladder calculi. It was able to vaporize all bladder calculi and provides a single modality of treating other associated genitourinary pathology.

  1. Spectroscopic properties of bismuth-germanate glasses co-doped with erbium and holmium ions

    NASA Astrophysics Data System (ADS)

    Ragin, Tomasz; Kochanowicz, Marcin; Żmojda, Jacek; Dorosz, Dominik

    2014-05-01

    In the article an analysis of thermal and spectroscopic properties of heavy metal oxide glasses from the Bi2O3-Ga2O3- Na2O-Ge2O3 system doped with rare earth elements were presented. It has been focused on the elaboration of the glass composition in terms of low phonon energy, high transparency in the range of infrared region and high thermal stability (ΔT=160 °C) required in optical fiber technology. Fabricated glasses co-doped with Er3+/Ho3+ions under 980 nm laser diode excitation exhibit emission at 1.55 μm (Er3+: 4I 13/2 → 4I15/2) and 2.0 μm (Ho3+: 4I7 → 5I8). The emission at 2.0 μm results from the Er3+ → Ho3+energy transfer. Taking into account great thermal stability and good optical properties such as high transparency (up to 80%) or high refractive index (2.23), the fabricated bismuth-germanate glass co-doped with Er3+/Ho3+ is promising material for construction of active optical fibers operating in the range of mid-infrared.

  2. Percutaneous holmium laser fulguration of calyceal diverticula.

    PubMed

    Alwaal, Amjad; Azhar, Raed A; Andonian, Sero

    2012-01-01

    Introduction. Calyceal diverticular stones are uncommon findings that represent a challenge in their treatment, due to the technical difficulty in accessing the diverticulum, and the high risk of their recurrence. Current percutaneous technique for calyceal diverticular stones involves establishing a renal access, clearing the stone, and fulguration of the diverticular lining with a roller-ball cautery electrode using hypotonic irrigation solution such as sterile water or glycine solution which may be associated with the absorption of hypotonic fluids with its inherent electrolyte disturbances. Case Report. In this paper, we present for the first time percutaneous holmium laser fulguration of calyceal diverticula in 2 patients using normal saline. Their immediate postoperative sodium was unchanged and their follow-up imaging showed absence of stones. Both patients remain asymptomatic at 30 months post-operatively. Conclusion. This demonstrates that holmium laser is a safe alternative method to fulgurate the calyceal diverticulum after clearing the stone percutaneously. PMID:22606636

  3. Holmium laser for multifunctional use in urology

    NASA Astrophysics Data System (ADS)

    Watson, Graham M.; Shroff, Sunil; Thomas, Robert; Kellett, Michael

    1994-05-01

    The holmium laser pulsed at 350 microsecond cuts tissue and fragments calculi. It has been assessed for minimally invasive urological intervention. It is useful for partly excising and partly coagulating tumors, incising strictures and the obstructed PUJ. It partly drill and partly fragments urinary calculi however hard. Other lasers are more effective at any one particular application, but this laser is a useful compromise as a multifunctional device.

  4. Semiconductor disk laser-pumped subpicosecond holmium fibre laser

    SciTech Connect

    Chamorovskiy, A Yu; Marakulin, A V; Leinonen, T; Kurkov, Andrei S; Okhotnikov, Oleg G

    2012-01-31

    The first passively mode-locked holmium fibre laser has been demonstrated, with a semiconductor saturable absorber mirror (SESAM) as a mode locker. Semiconductor disk lasers have been used for the first time to pump holmium fibre lasers. We obtained 830-fs pulses at a repetition rate of 34 MHz with an average output power of 6.6 mW.

  5. Laser cooling, trapping, and Rydberg spectroscopy of neutral holmium atoms

    NASA Astrophysics Data System (ADS)

    Hostetter, James Allen

    This thesis focuses on progress towards using ensembles of neutral holmium for use in quantum computing operations. We are particularly interested in using a switchable interaction between neutral atoms, the Rydberg blockade, to implement a universal set of quantum gates in a collective encoding scheme that presents many benefits over quantum computing schemes which rely on physically distinct qubits. We show that holmium is uniquely suited for operations in a collective encoding basis because it has 128 ground hyperfine states, the largest number of any stable, neutral atom. Holmium is a rare earth atom that is very poorly described for our purposes as it has never been cooled and trapped, its spectrum is largely unknown, and it presents several unique experimental challenges related to its complicated atomic structure and short wavelength transitions. We demonstrate important progress towards overcoming these challenges. We produce the first laser cooling and trapping of holmium into a MOT. Because we use a broad cooling transition, our cooling technique does not require the use of a Zeeman slower. Using MOT depletion spectroscopy, we provide precise measurements of holmium's Rydberg states and its ionization potential. Our work continues towards cooling holmium into a dipole trap by calculating holmium's AC polarizability and demonstrating the results of early attempts at an optical dipole trap. We provide details of future upgrades to the experimental apparatus and discuss interesting potential for using holmium in quantum computing using single atoms in a magnetically trapped lattice. This thesis shows several promising indicators for continued work in this field.

  6. 4f electron delocalization and volume collapse in praseodymium metal

    SciTech Connect

    Bradley, Joseph A.; Moore, Kevin T.; Lipp, Magnus J.; Mattern, Brian A.; Pacold, Joseph I.; Seidler, Gerald T.; Chow, Paul; Rod, Eric; Xiao, Yuming; Evans, William J.

    2012-04-17

    We study the pressure evolution of the 4f electrons in elemental praseodymium metal compressed through several crystallographic phases, including the large volume-collapse transition at 20 GPa. Using resonant x-ray emission, we directly and quantitatively measure the development of multiple electronic configurations with differing 4f occupation numbers, the key quantum observable related to the delocalization of the strongly correlated 4f electrons. These results provide a high-fidelity test of prior predictions by dynamical mean-field theory, and support the hypothesis of a strong connection between electronic and structural degrees of freedom at the volume-collapse transition.

  7. Nonaaqua-praseodymium triiodide-thio-urea (1/2).

    PubMed

    Antonenko, Taisia A; Alikberova, Lyudmila Yu; Albov, Dmitry V

    2012-02-01

    The title compound, [Pr(H(2)O)(9)]I(3)·2CS(NH(2))(2), an adduct of nona-aqua-praseodymium triiodide with two thio-urea mol-ecules, is composed from [Pr(H(2)O)(9)](3+) cations (polyhedron: monocapped tetra-gonal anti-prism), noncoordinated thio-urea mol-ecules and iodide anions. The components are evidently connected by hydrogen bonds but in the presence of heavy atoms water H atoms have not been located. The complex cation and one of the two independent iodide anions are located on a twofold axis. PMID:22346801

  8. Holmium fibre laser with record quantum efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Tsvetkov, V B; Marakulin, A V; Minashina, L A; Medvedkov, O I; Kosolapov, A F

    2011-06-30

    We report holmium-doped fibre lasers with a Ho{sup 3+} concentration of 1.6 x 10{sup 19} cm{sup -3} and lasing wavelengths of 2.02, 2.05, 2.07 and 2.1 {mu}m at a pump wavelength of 1.15 {mu}m. The slope efficiency of the lasers has been measured. The maximum efficiency, 0.455, has been obtained at a lasing wavelength of 2.05 {mu}m. The laser efficiency is influenced by both the optical loss in the wing of a vibrational absorption band of silica and active-ion clustering. (lasers)

  9. Holmium: YAG laser resection of the prostate.

    PubMed

    Bukala, B; Denstedt, J D

    1999-04-01

    The holmium laser is a relatively new multipurpose medical laser that recently became available for use in urology. There has been considerable interest in this device, as it seems to combine the cutting properties of the carbon dioxide laser with the coagulating properties of the neodymium:YAG laser, making it particularly appealing for many surgical applications. The last decade has seen enthusiasm for the use of laser energy for the treatment of benign prostatic hyperplasia. In this article, we review the technique of Ho:YAG laser resection of the prostate, including the essential equipment and perioperative patient care. PMID:10360503

  10. Properties of holmium implanted gold films and yttrium silicide to use as absorbers in microcalorimeters for a holmium neutrino mass experiment

    NASA Astrophysics Data System (ADS)

    Prasai, Krishna P.

    In recent years, there has been huge improvement in microcalorimetric technology and its applications. Today's cryogenic microcalorimeter technology can be used in a large scale experiment with excellent energy and time resolutions. Transition Edge Sensor (TES) microcalorimeters are being developed as imaging spectrometers for a wide range of applications including neutrino mass measurement. We are developing a source (163Ho) embedded TES microcalorimeter for neutrino mass measurement. Energy resolution, rise time of events, decay time, and read-out electronics must be considered carefully in designing a microcalorimeter for the application of neutrino mass experiments. Our research is particularly focused on the investigation of the properties of the 163Ho imbedded metallic absorber for the application of the Ho-neutrino mass experiment. In a microcalorimetric neutrino mass experiment using the radioactive decay of 163Ho, the radioactive material must be fully embedded in the microcalorimeter absorber. One option that is being investigated is to implant the radioactive isotope into a gold absorber, as gold is successfully used in other applications. However, knowing the thermal properties at the working temperature of microcalorimeters is critical for choosing the absorber material and for optimizing the detector performance. In particular, it is paramount to understand if implanting the radioactive material in gold changes its heat capacity. We used a bolometric technique to measure the heat capacity of gold films, implanted with various concentrations of holmium and erbium (a byproduct of the 163Ho fabrication), in the temperature range 70 mK to 300 mK. Our results show that the specific heat capacity of the gold films is not affected by the implant, making this a viable option for a future microcalorimeter holmium experiment. Furthermore, most chemical processes to extract the Ho-163 isotope and insert it into a detector absorber involve yttrium based compounds

  11. Holmium laser resection of the prostate.

    PubMed

    Matsuoka, K; Iida, S; Tomiyasu, K; Shimada, A; Suekane, S; Noda, S

    1998-06-01

    A total of 35 patients with benign prostatic hyperplasia (BPH) were treated with the Ho: YAG laser using a new technique termed holmium laser resection of the prostate or HoLRP. The laser energy was applied directly to prostatic tissue exclusively through the use of a standard 550 micron end-firing fiber. A high-powered holmium laser was used and was set at 2.4 J per pulse at 25 pulses per second for an average power of 60 W. The mean preoperative AUA Symptom Score was 24. Postoperatively, the score dropped to 10.9, 8.2, 5.2, and 4.6 at 1 week, 1 month, 3 months, and 6 months, respectively. The peak urine flow rate improved from 6.3 mL/sec preoperatively to 15.1, 15.3 and 16 mL/sec at 1 week, 1 month, 3 months, and 6 months. A foley catheter was removed within 24 hours of completion of the operation in 31 patients (89%), and voiding was improved. The HoLRP technique was bloodless, and the short-term results were satisfactory. Most importantly, the defect produced by HoLRP is identical to that of a conventional transurethral resection. These initial results demonstrate that HoLRP is a useful surgical alternative in the treatment of patients with obstructive BPH. PMID:9658303

  12. Perspectives of holmium laser resection of the prostate: cutting effects with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Eichenauer, Rolf H.; Droege, Gerit; Brinkmann, Ralf; Neuss, Malte; Gafumbegete, Evariste; Jocham, Dieter

    1998-07-01

    Laser prostatectomy shows an improvement in peak urinary flow rates, in post-void residual urine volumes and also a symptomatic improvement when compared to the transurethral resection of the prostate (TUR-P). Time to achieve symptomatic improvement is delayed with many established laser procedures compared to standard resection. However, this disadvantage can be solved with a new resection technique using a pulsed holmium laser. Nevertheless, this advanced technique shows a few problems in a first clinical trial. Besides this clinical study, in vitro experiments were carried out in order to determine the optimal irradiation parameters with respect to resection rate, incision/ablation quality and handling. Prostate tissue of radical prostatectomies and chicken breast as model were irradiated with a pulsed holmium-laser in vitro with different laser parameters using a bare fiber in contact to tissue. The incision quality (depths and coagulation/vaporization effects) was analyzed with regard to pulse energy (speed of incision, angle of incision) and fiber diameter. Fast flash photography was performed to analyze thermo-mechanical side-effects. Fast flash photography reveals cavitation bubble up to 7 mm length in water and dissections in tissue. The ablation rate increases proportional to the laser pulse energy. The Holmium Laser Resection of the Prostate (HOLRP) in humans with available instrumentation right now shows equieffective results compared to the transurethral resection, no need for transfusion, no transurethral resection syndrome, short time for catheterization. Further technical approvement may significantly improve holmium laser prostate resection. We present a new application system for the laser resection.

  13. Near-equilibrium polymorphic phase transformations in Praseodymium under dynamic compression

    SciTech Connect

    Bastea, M; Reisman, D

    2007-02-12

    We report the first experimental observation of sequential, multiple polymorphic phase transformations occurring in Praseodymium dynamically compressed using a ramp wave. The experiments also display the signatures of reverse transformations occuring upon pressure release and reveal the presence of small hysteresys loops. The results are in very good agreement with equilibrium hydrodynamic calculations performed using a thermodynamically consistent, multi-phase equation of state for Praseodymium, suggesting a near-equilibrium transformation behavior.

  14. Magneto-optical trapping of holmium atoms

    NASA Astrophysics Data System (ADS)

    Miao, J.; Hostetter, J.; Stratis, G.; Saffman, M.

    2014-04-01

    We demonstrate sub-Doppler laser cooling and magneto-optical trapping of the rare-earth element holmium. Atoms are loaded from an atomic beam source and captured in six-beam σ+-σ- molasses using a strong J =15/2↔J=17/2 cycling transition at λ =410.5 nm. Due to the small difference in hyperfine splittings and Landé g factors in the lower and upper levels of the cooling transition the MOT is self-repumped without additional repump light, and deep sub-Doppler cooling is achieved with the magnetic trap turned on. We measure the leakage out of the cycling transition to metastable states and find a branching ratio <10-5, which is adequate for state-resolved measurements on hyperfine encoded qubits.

  15. Midline Prostatic Cyst Marsupialization Using Holmium Laser.

    PubMed

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  16. Midline Prostatic Cyst Marsupialization Using Holmium Laser

    PubMed Central

    Kilinc, Mehmet; Goger, Yunus Emre; Piskin, Mesut; Balasar, Mehmet; Kandemir, Abdulkadir

    2015-01-01

    Many of the prostatic cysts are asymptomatic and only 5% are symptomatic (Hamper et al., 1990; Higashi et al., 1990). These symptoms include pelvic pain, hematospermia, infertility, voiding dysfunction, prostatitis-like syndrome, and painful ejaculation. Treatment of prostatic cysts includes TRUSG guided drainage, endoscopic transurethral resection, and in some cases even open surgery. In the literature, endoscopic interventions use marsupialization of the midline prostatic cyst with transurethral resection (TUR) or transurethral incision with endoscopic urethrotomy (Dik et al., 1996; Terris, 1995). Holmium: YAG laser was employed for the marsupialization of the cyst wall in midline prostatic cyst treatment for the first time in the present study. Symptoms, treatment, and follow-up are presented in this paper. PMID:26101688

  17. Quantum state control of trapped Holmium atoms

    NASA Astrophysics Data System (ADS)

    Hostetter, James; Yip, Christopher; Milner, William; Booth, Donald; Collett, Jeffrey; Saffman, Mark

    2016-05-01

    Neutral Holmium with its large number of hyperfine ground states provides a promising approach for collective encoding of a multi-qubit register. A prerequisite for collective encoding is the ability to prepare different states in the 128 state hyperfine ground manifold. We report progress towards optical pumping and control of the hyperfine Zeeman state of trapped Ho atoms. Atoms are transferred from a 410.5 nm MOT into a 455 nm optical dipole trap. The atoms can be optically pumped using light driving the ground 6s2 , F = 11 to 6 s 6 p ,F' = 11 transition together with a F = 10 to F' = 11 repumper. Microwave fields are then used to drive transitions to hyperfine levels with 4 <= F <= 11 . Work supported by NSF award PHY-1404357.

  18. Power scaling of semiconductor laser pumped Praseodymium-lasers

    NASA Astrophysics Data System (ADS)

    Richter, A.; Heumann, E.; Huber, G.; Ostroumov, V.; Seelert, W.

    2007-04-01

    We report on efficient lasing of Pr-doped fluoride materials with cw output powers up to 600 mW in the visible spectral range. Praseodymium doped LiYF4 and LiLuF4 crystals were pumped either by an intracavity frequency doubled optically pumped semiconductor laser with output powers up to 1.6 W and nearly diffraction limited beam quality or by a multimode GaN-laser diode with an output power of about 370 mW. Furthermore, intracavity frequency doubling of the red Pr-laser radiation to 320 nm reaching output powers of more than 360 mW with a conversion efficiency of 61% and an optical-to-optical efficiency of 22% are presented.

  19. Electrical properties of praseodymium oxide doped Boro-Tellurite glasses

    NASA Astrophysics Data System (ADS)

    Jagadeesha Gowda G., V.; Devaraja, C.; Eraiah, B.

    2016-05-01

    Glasses of the composition xPr6O11- (35-x)TeO2-65B2O3 (x=0, 0.1 to 0.5 mol %) have been prepared using the melt quenching method. The ac and dc conductivity of glass have been measured over a wide range of frequencies and temperatures. Experimental results indicate that the ac conductivity depend on temperature, frequency and Praseodymium content. The conductivity as a function of frequency exhibited two components: dc conductivity (σdc), and ac conductivity (σac). The activation energies are estimated and found to be decreases with composition. The impedance plot at each temperature appeared as a semicircle passes through the origin.

  20. Erbium-doped aluminophosphosilicate optical fibres

    SciTech Connect

    Likhachev, M E; Bubnov, M M; Zotov, K V; Medvedkov, O I; Lipatov, D S; Yashkov, M V; Gur'yanov, Aleksei N

    2010-09-10

    We have studied the active properties of erbium-doped aluminophosphosilicate (APS) core fibres in wide ranges of erbia, alumina and phosphorus pentoxide concentrations. The absorption and luminescence spectra of the P{sub 2}O{sub 5}- or Al{sub 2}O{sub 3}-enriched erbium-doped APS fibres are shown to be similar to those of the erbium-doped fibres singly doped with phosphorus pentoxide or alumina, respectively. The formation of AlPO{sub 4} in APS fibres leads not only to a reduction in the refractive index of the glass but also to a marked increase in Er{sub 2}O{sub 3} solubility in silica. (optical fibres)

  1. Anisotropic optical trapping of ultracold erbium atoms

    NASA Astrophysics Data System (ADS)

    Dulieu, Olivier; Lepers, Maxence; Wyart, Jean-Francois

    2014-05-01

    We calculate the complex dynamic dipole polarizability of ground-state erbium, a rare-earth atom that was recently Bose-condensed. This quantity determines the trapping conditions of cold atoms in an optical trap. The polarizability is calculated with the sum-over-state formula inherent to second-order perturbation theory. The summation is performed on transition energies and transition dipole moments from ground-state erbium, which are computed using the Racah-Slater least-square fitting procedure provided by the Cowan codes. This allows us to predict several yet unobserved energy levels in the range 25000-31000 cm-1 above the ground state. Regarding the trapping potential, we find that ground-state erbium essentially behaves like a spherically-symmetric atom, in spite of its large electronic angular momentum. We find a mostly isotropic van der Waals interaction between two ground-state erbium atoms, with a coefficient C6iso= 1760 a.u.. On the contrary, the photon-scattering rate is strongly anisotropic with respect to the polarization of the trapping light. also at LERMA, UMR8112, Observatoire de Paris-Meudon, Univ. Pierre et Marie Curie, Meudon, France.

  2. Anisotropic optical trapping of ultracold erbium atoms

    NASA Astrophysics Data System (ADS)

    Lepers, M.; Wyart, J.-F.; Dulieu, O.

    2014-02-01

    Ultracold atoms confined in a dipole trap are submitted to a potential whose depth is proportional to the real part of their dynamic dipole polarizability. The atoms also experience photon scattering whose rate is proportional to the imaginary part of their dynamic dipole polarizability. In this article we calculate the complex dynamic dipole polarizability of ground-state erbium, a rare-earth atom that was recently Bose condensed. The polarizability is calculated with the sum-over-state formula inherent to second-order perturbation theory. The summation is performed on transition energies and transition dipole moments from ground-state erbium, which are computed using the Racah-Slater least-squares fitting procedure provided by the cowan codes. This allows us to predict nine unobserved odd-parity energy levels of total angular momentum J =5, 6, and 7, in the range 25 000-31 000 cm-1 above the ground state. Regarding the trapping potential, we find that ground-state erbium essentially behaves like a spherically symmetric atom, in spite of its large electronic angular momentum. We also find a mostly isotropic van der Waals interaction between two ground-state erbium atoms, characterized by a coefficient C6iso=1760 a.u. To the contrary, the photon-scattering rate shows a pronounced anisotropy since it strongly depends on the polarization of the trapping light.

  3. Erbium:YAG laser for cataract extraction

    NASA Astrophysics Data System (ADS)

    Snyder, Robert W.; Jani, Mahendra G.; Yarborough, Mike; Marcellino, George R.; Noecker, Robert J.; Kramer, Theresa R.; Vidaurri, Jesus

    1998-06-01

    The Erbium:YAG laser may be an effective laser for use in cataract surgery. At 2.94 mm the energy is maximally absorbed by water thereby efficiently disrupting tissue with minimal surrounding thermal damage. The laser may be safer to use in the eye than conventional ultrasonic emulsifiers. Preliminary clinical studies of the safety and efficacy have begun.

  4. Erbium hydride thermal desorption : controlling kinetics.

    SciTech Connect

    Ferrizz, Robert Matthew

    2007-08-01

    Thermal desorption spectroscopy (TDS) is used to study the decomposition kinetics of erbium hydride thin films. The TDS results presented in this report show that hydride film processing parameters directly impact thermal stability. Issues to be addressed include desorption kinetics for dihydrides and trihydrides, and the effect of film growth parameters, loading parameters, and substrate selection on desorption kinetics.

  5. Delayed stimulated afterglow from holmium ions in crystals with coactivators

    SciTech Connect

    Petrov, M.V.; Tkachuk, A.M.

    1980-12-01

    Delayed stimulated afterglow from holmium ions in ..cap alpha beta..-SrF/sub 2/-YF/sub 3/ crystals was observed and investigated. This took the form of several series of emission spikes separated by dark intervals after the action of a single pump pulse. The effect is attributed to some features of the mechanism for population of the upper active level of the lasing holmium ion in the presence of sensitizer ions. It is found that in order to observe the effect, the system must incorporate a metastable level from which energy transfer to the active level provides an independent ''additional pumping'' system for the holmium ions acting over times much longer than the pump pulse duration.

  6. Use of the holmium:YAG laser in urology

    NASA Astrophysics Data System (ADS)

    Mattioli, Stefano

    1997-12-01

    The Holmium-YAG is a versatile laser with multiple soft- tissue applications including tissue incision and vaporization, and pulsed-laser applications such as lithotripsy. At 2140 nanometers, the wavelength is highly absorbed by tissue water. Further, like CO2 laser, the Holmium produces immediate tissue vaporization while minimizing deep thermal damage to surrounding tissues. It is an excellent instrument for endopyelotomy, internal urethrotomy, bladder neck incisions and it can be used to resect the prostate. The Holmium creates an acute TUR defect which gives immediate results like the TURP. More than 50 patients were treated from Jan. 1996 to Jan. 1997 for obstructive symptoms due to benign prostatic hyperplasia, bladder neck stricture, urethral stenosis, and superficial bladder tumors.

  7. High gain holmium-doped fibre amplifiers.

    PubMed

    Simakov, Nikita; Li, Zhihong; Jung, Yongmin; Daniel, Jae M O; Barua, Pranabesh; Shardlow, Peter C; Liang, Sijing; Sahu, Jayanta K; Hemming, Alexander; Clarkson, W Andrew; Alam, Shaif-Ul; Richardson, David J

    2016-06-27

    We investigate the operation of holmium-doped fibre amplifiers (HDFAs) in the 2.1 µm spectral region. For the first time we demonstrate a diode-pumped HDFA. This amplifier provides a peak gain of 25 dB at 2040 nm with a 15 dB gain window spanning the wavelength range 2030 - 2100 nm with an external noise figure (NF) of 4-6 dB. We also compare the operation of HDFAs when pumped at 1950 nm and 2008 nm. The 1950 nm pumped HDFA provides 41 dB peak gain at 2060 nm with 15 dB of gain spanning the wavelength range 2050 - 2120 nm and an external NF of 7-10 dB. By pumping at the longer wavelength of 2008 nm the gain bandwidth of the amplifier is shifted to longer wavelengths and using this architecture a HDFA was demonstrated with a peak gain of 39 dB at 2090 nm and 15 dB of gain spanning the wavelength range 2050 - 2150 nm. The external NF over this wavelength range was 8-14 dB. PMID:27410557

  8. Holmium laser urethrotomy for urethral stricture.

    PubMed

    Hossain, A Z M Z; Khan, S A; Hossain, S; Salam, M A

    2004-08-01

    A prospective cross-sectional study was carried-out in the department of urology, Dhaka Medical College Hospital (DMCH) to evaluate the outcome of Laser urethrotomy for the treatment of urethral stricture. For this purpose, 30 male patients aged 15 to 60 years with short segment anterior urethral stricture (>2cm) were treated by HO:YAG Laser. The energy used for this purpose was 0.8 to 1.5 joules by LISA 80 Watt Holmium Laser machine. All patients were catheterized for less than 24 hours and were followed up for 6 to 12 months postoperatively by uroflowmetry and by retrograde with voiding cystourethrogram 3 monthly. The study revealed that out of 30 patients, 27(90%) showed good flow of urine (Qave>16.0 ml/sec) and adequate caliber urethra in retrograde urethrogram (RGU). Only 3(10%) patients showed narrow stream of urine (Qave<8.0 ml/sec) and recurrent stricture in RGU which were managed by optical internal urethrotomy (OIU) and clean intermittent self catheterization (CISC). The study showed satisfactory results in 90% cases with short term follow up. The study concludes that HO:YAG Laser urethrotomy for the treatment of short segment urethral stricture is highly effective. The study further reveals that the method is simple, safe and thus, it can be considered favorably as a new therapeutic option for the treatment of urethral stricture. However, long term follow up is necessary for making a final comment on this issue. PMID:15813486

  9. Holmium:YAG laser stapedotomy: preliminary evaluation

    NASA Astrophysics Data System (ADS)

    Stubig, Ingrid M.; Reder, Paul A.; Facer, G. W.; Rylander, Henry G.; Welch, Ashley J.

    1993-07-01

    This study investigated the use of a pulsed Holmium:YAG ((lambda) equals 2.09 micrometers ) laser- fiber microsurgical system for laser stapedotomy. This system ablates human stapes bones effectively with minimal thermal damage. The study was designed to determine the effectiveness of the Ho:YAG laser (Schwartz Electro Optics, Inc., Orlando, FL) for stapedotomy and to evaluate temperature changes within the cochlea during the ablation process. Human cadaveric temporal bones were obtained and the stapes portion of the ossicular chain was removed. A 200 micrometers diameter low OH quartz fiber was used to irradiate these stapes bones in an air environment. The laser was pulsed at 2 Hz, 250 microsecond(s) ec pulse width and an irradiance range of 100 - 240 J/cm2 was used to ablate holes in the stapes footplate. The resultant stapedotomies created had smooth 300 micrometers diameter holes with a minimum of circumferential charring. Animal studies in-vivo were carried out in chinchillas to determine the caloric spread within the cochlea. A 0.075 mm Type T thermocouple was placed in the round window. Average temperature change during irradiation of the stapes footplate recorded in the round window was 3.6 degree(s)C. The data suggest that stapedotomy using the Ho:YAG laser can result in a controlled ablation of the stapes footplate with minimal thermal damage to the surrounding stapes. Optical coupling using fiberoptic silica fibers is an ideal method for delivering laser energy to the stapes during stapedotomy.

  10. Gain and energy storage in holmium YLF

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.; Deyst, John P.

    1991-01-01

    It is demonstrated that Q-switched holmium lasers are capable of high-gain and high-energy operation at 300 K. Small-signal gain coefficients of 0.50 and 0.12/cm have been measured in YLF and YAG, respectively. Small-signal gains of 0.50/cm are comparable to those achievable in Nd:YAG and are not typical of low-gain materials. This large gain in the Ho:YLF material is made possible by operating the amplifier in the ground state depletion mode. The amplifier performance data and associated analysis presented demonstrate that efficient energy storage is possible with very high excited state ion densities of the Ho 5I7 upper laser level. This is an important result since upconversion can limit the 5I7 population. Although upconversion was still present in this experiment, it was possible to achieve efficient energy storage, demonstrating that the problem is manageable even at high excitation densities in YLF.

  11. Holmium:YAG laser coronary angioplasty in acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Patients who sustain complicated acute myocardial infarction in whom thrombolytic agents either fail or are contraindicated often need mechanical revascularization other than PTCA. In 24 patients with acute infarction complicated by continuous chest pain and ischemia who either received lytics or with contraindication to lytics, a holmium:YAG laser (Eclipse Surgical Technologies, Palo Alto, CA) was utilized for thrombolysis and plaque ablation. Clinical success was achieved in 23/24 patients, with 23 patients (94%) surviving the acute infarction. Holmium:YAG laser is very effective and safe in thrombolysis and revascularization in this complicated clinical setting.

  12. Variable valence of praseodymium in rare-earth oxide solid solutions

    SciTech Connect

    Kravchinskaya, M.V.; Merezhinskii, K.Y.; Tikhonov, P.A.

    1986-06-01

    Solid solutions of elevated praseodymium oxide content have interesting electrical properties, making them the basis for the manufacture of high-temperature electrically conducting materials. Establishment of the composition-structure-valence state relationships enables control of the material properties. The authors performed investigations using a thermogravimetric apparatus with an electronic microbalance of type EM-5-3M, and using x-ray phase analysis of powders (DRON-1 diffractometer, CuK /SUB alpha/ -radiation). The authors also studied the kinetics of praseodymium oxidation with a thermogravimetric apparatus under isothermal conditions. Evaluation of the results with the equation of Kolmogorov, Erofeev, and Avraam indicates that the process is limited by the chemical oxidation of praseodymium and not by diffusion.

  13. Molecular distribution and toxicity assessment of praseodymium by Spirodela polyrrhiza.

    PubMed

    Xu, Ting; Su, Chunlei; Hu, Dan; Li, Feifei; Lu, Qianqian; Zhang, Tingting; Xu, Qinsong

    2016-07-15

    Aquatic macrophytes are known to accumulate and bioconcentrate metals. In this study, the physiological, biochemical, and ultrastructural responses of Spirodela polyrrhiza to elevated concentrations of praseodymium (Pr), ranging from 0 to 60μM, were investigated over 20 d exposure. The results showed that the accumulation of Pr in S. polyrrhiza occurred in a concentration-dependent manner. The accumulation of Pr in biomacromolecules decreased in the order of cellulose and pectin (65-69%), crude proteins (18-25%), crude polysaccharides (6-10%), crude lipids (3%-4%). Significant increases in malondialdehyde (MDA), and decreases in photosynthetic pigment, soluble protein, and unsaturated fatty acids showed that Pr induced oxidative stress. Inhibitory effects on photosystem II and the degradation of the reaction center proteins D1 and D2 were revealed by chlorophyll a fluorescence transients, immunoblotting, and damage to chloroplast ultrastructure. Significant increases in cell death were observed in Pr-treated plants. However, S. polyrrhiza can combat Pr induced oxidative injury by activating various enzymatic and non-enzymatic antioxidants. These results will improve understanding of the biological consequences of rare earth elements (REEs) contamination, particularly in aquatic bodies. PMID:27017399

  14. Mechanical and Thermal Properties of Praseodymium Monopnictides: AN Ultrasonic Study

    NASA Astrophysics Data System (ADS)

    Bhalla, Vyoma; Kumar, Raj; Tripathy, Chinmayee; Singh, Devraj

    2013-09-01

    We have computed ultrasonic attenuation, acoustic coupling constants and ultrasonic velocities of praseodymium monopnictides PrX(X: N, P, As, Sb and Bi) along the <100>, <110>, <111> in the temperature range 100-500 K using higher order elastic constants. The higher order elastic constants are evaluated using Coulomb and Born-Mayer potential with two basic parameters viz. nearest-neighbor distance and hardness parameter in the temperature range of 0-500 K. Several other mechanical and thermal parameters like bulk modulus, shear modulus, Young's modulus, Poisson ratio, anisotropic ratio, tetragonal moduli, Breazeale's nonlinearity parameter and Debye temperature are also calculated. In the present study, the fracture/toughness (B/G) ratio is less than 1.75 which implies that PrX compounds are brittle in nature at room temperature. The chosen material fulfilled Born criterion of mechanical stability. We also found the deviation of Cauchy's relation at higher temperatures. PrN is most stable material as it has highest valued higher order elastic constants as well as the ultrasonic velocity. Further, the lattice thermal conductivity using modified approach of Slack and Berman is determined at room temperature. The ultrasonic attenuation due to phonon-phonon interaction and thermoelastic relaxation mechanisms have been computed using modified Mason's approach. The results with other well-known physical properties are useful for industrial applications.

  15. Synthesis and structural studies of praseodymium doped silver borate glasses

    SciTech Connect

    Jagadeesha Gowda, G. V.; Eraiah, B.

    2013-02-05

    Praseodymium doped silver borate glasses with nominal composition xPr{sub 6}O{sub 11}-(25-x)Ag{sub 2}O-75B{sub 2}O{sub 3} (x=0, 1, 2, 3, 4, 5) were prepared by melt quench technique. XRD pattern shows that there is no sharp peak it confirms the amorphous nature of the present glasses. The glass transition temperature (T{sub g}) of this glass system have been studied using the Matac MBS-8000 Digital Signal Processing and Conventional Thermal Analysis (DTA) method. The T{sub g} of these glasses increases with increase in concentration of Pr{sub 6}O{sub 11} except at 0.2 mol%, T{sub g} value is lower. {sup 11}B MAS-NMR shows the presence of sharp peak around 0.306 ppm. Chemical shift of these glasses decreases with mol% of rare earth oxide. FTIR spectra recorded in the region of 400 to 4000 cm{sup -1}. This studies revealed that the progressive addition Ag{sub 2}O and Pr{sub 6}O{sub 11} leads to modification of B{sub 2}O{sub 3} into BO{sub 4} groups. Raman measurements of these glasses support the proposed interpretations of the experimental results.

  16. Solvent extraction studies of holmium with acidic extractants

    SciTech Connect

    Gaikwad, A.G.; Damodaran, A.D. )

    1993-03-01

    Liquid-liquid extraction studies of holmium with 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester, naphthenic, and Versatic 10 acids have been carried out. The nature of the extracted species and the extraction equilibrium constants of these systems have been determined from aqueous nitrate solution. The extraction mechanism and complexation models have been proposed. 11 refs., 8 figs.

  17. Spectral performance of monolithic holmium and thulium lasers

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1991-01-01

    Fabry-Perot resonators have been used to demonstrate single-mode lasing of holmium and neodymium YAG. The previous demonstration in the holmium laser required TE cooling the crystal to -15 C in order to achieve threshold. The present study extends that result, demonstrating +25 C operation in a 1-mm thick plano/plano resonator. The experimental configuration of lasing both the holmium and thulium lasers used a 500-mW diode laser which was collimated, circularized, and focused into a beam radius of 60 microns. The single-frequency lasing spectrum of the holmium laser is shown. By adjusting the mirror reflectivity, the ability to control the laser's wavelength is demonstrated. This laser operated with 11 mW of optical power, a 57-percent slope efficiency, and 120-mW threshold vs absorbed diode power laser for the 60-micron beam radius. The thulium laser operated very efficiently at room temperature, but on seven longitudinal modes. The Tm:TAG laser exhibits typical characteristics of spatial hole burning not seen in the Ho:Tm:YAG for flat/flat resonators.

  18. Percutaneous laser disc decompression with the holmium: YAG laser.

    PubMed

    Casper, G D; Hartman, V L; Mullins, L L

    1995-06-01

    This article discusses the evolution of the percutaneous laser disc decompression (PLDD) method using a holmium:YAG laser. Advantages of using this wavelength and several techniques for its use in PLDD are reviewed. The article also discusses the current devices and delivery systems available for this application. PMID:10150646

  19. Synthesis, characterization, and neutron activation of holmium metallofullerenes

    SciTech Connect

    Cagle, D.W.; Thrash, T.P.; Wilson, L.J.; Alford, M.; Chibante, L.P.F.; Ehrhardt, G.J.

    1996-08-28

    Isolation of the first macroscopic quantities of endohedral holmium metallofullerenes (principally Ho@C{sub 82}, Ho{sub 2}@C{sub 82}, and Ho{sub 3}@C{sub 82} by LD-TOF mass spectrometry) has been accomplished by carbon-arc and preparative HPLC methodologies. The detailed procedure for production and isolation of the metallofullerenes includes a new technique whereby holmium-impregnated electrodes are prepared simply by soaking porous graphite rods in an ethanolic solution of Ho(NO{sub 3}){sub 3}.xH{sub 2}O. Monoisotopic {sup 165}Ho offers a unique combination of advantages for neutron-activation studies of metallofullerenes, and purified samples containing {sup 165}Ho@C{sub 82}, {sup 165}Ho{sub 2}@C{sub 82}, and {sup 165}Ho{sub 3}@C{sub 82} have been activated by high-flux neutron irradiation ({Phi} = 4 x 10{sup 13}n cm{sup -2} s{sup -1}) to generate {sup 166}Ho metallofullerenes, which undergo {beta}{sup -} decay to produce stable {sup 166}Er. Chemical workup of the irradiated samples, followed by re-irradiation, has been used to demonstrate that observed decomposition of holmium metallofullerenes is due mainly to `fast` neutron damage rather than to holmium atom nuclear recoil (E{sub max} = 200 eV). This implies that metallofullerene damage can be minimized by using neutron fluxes with the highest possible thermal component. 60 refs., 4 figs.

  20. Hemangioma of the prostatic urethra: holmium laser treatment.

    PubMed

    de León, Javier Ponce; Arce, Jacobo; Gausa, Luís; Villavicencio, Humberto

    2008-01-01

    Urethral hemangiomas are benign vascular tumors that are found in perimontanal prostatic localization and less frequently in the urethra. Although different urethral procedures have been postulated for its treatment, the best results are achieved using lasers. A patient who underwent endoscopic holmium laser treatment for such hemangiomas is presented. Total disappearance of the lesions without any complications was achieved. PMID:18204245

  1. Hybrid quantum circuit with implanted erbium ions

    SciTech Connect

    Probst, S.; Rotzinger, H.; Tkalčec, A.; Kukharchyk, N.; Wieck, A. D.; Wünsch, S.; Siegel, M.; Ustinov, A. V.; Bushev, P. A.

    2014-10-20

    We report on hybrid circuit quantum electrodynamics experiments with focused ion beam implanted Er{sup 3+} ions in Y{sub 2}SiO{sub 5} coupled to an array of superconducting lumped element microwave resonators. The Y{sub 2}SiO{sub 5} crystal is divided into several areas with distinct erbium doping concentrations, each coupled to a separate resonator. The coupling strength is varied from 5 MHz to 18.7 MHz, while the linewidth ranges between 50 MHz and 130 MHz. We confirm the paramagnetic properties of the implanted spin ensemble by evaluating the temperature dependence of the coupling. The efficiency of the implantation process is analyzed and the results are compared to a bulk doped Er:Y{sub 2}SiO{sub 5} sample. We demonstrate the integration of these engineered erbium spin ensembles with superconducting circuits.

  2. Characterization of the surface changes during the activation of erbium/erbium oxide for hydrogen storage.

    SciTech Connect

    Zavadil, Kevin Robert; Snow, Clark Sheldon; Brumbach, Michael Todd

    2010-09-01

    Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.

  3. α-Regioselective Barbier Reaction of Carbonyl Compounds and Allyl Halides Mediated by Praseodymium.

    PubMed

    Wu, San; Li, Ying; Zhang, Songlin

    2016-09-01

    The first utility of praseodymium as a mediating metal in the Barbier reaction of carbonyl compounds with allyl halides was reported in this paper. In contrast to the traditional metal-mediated or catalyzed Barbier reactions, exclusive α-adducts were obtained in this one-pot reaction with a broad scope of substrates and feasible reaction conditions. PMID:27490708

  4. Regioselective synthesis and molecular structure of the first derivative of praseodymium-containing metallofullerenes.

    PubMed

    Zhou, Qin; Li, Hui; Lian, Yongfu; Suzuki, Mitsuaki; Bao, Lipiao; Cai, Wenting; Wang, Weiwei; Nagase, Shigeru; Lu, Xing; Akasaka, Takeshi

    2014-09-01

    Regioselective cycloaddition of adamantylidene carbene to Pr@C(2v)(9)-C82 affords the first derivative of praseodymium-containing metallofullerenes. Single-crystal X-ray crystallographic data in combination with theoretical studies demonstrate that the addition is dictated by the single metal ion encapsulated inside the fullerene cage. PMID:25026192

  5. Thermodynamics of reaction of praseodymium with gallium-indium eutectic alloy

    NASA Astrophysics Data System (ADS)

    Melchakov, S. Yu.; Ivanov, V. A.; Yamshchikov, L. F.; Volkovich, V. A.; Osipenko, A. G.; Kormilitsyn, M. V.

    2013-06-01

    Thermodynamic properties of Ga-In eutectic alloys saturated with praseodymium were determined for the first time employing the electromotive force method. The equilibrium potentials of the Pr-In alloys saturated with praseodymium (8.7-12.1 mol.% Pr) and Pr-Ga-In alloys (containing 0.0012-6.71 mol.% Pr) were measured between 573-1073 K. Pr-In alloy containing solid PrIn3 with known thermodynamic properties was used as the reference electrode when measuring the potentials of ternary Pr-In-Ga alloys. Activity, partial and excessive thermodynamic functions of praseodymium in alloys with indium and Ga-In eutectic were calculated. Activity (a), activity coefficients (γ) and solubility (X) of praseodymium in the studied temperature range can be expressed by the following equations: lgaα-Pr(In) = 4.425 - 11965/T ± 0.026. lgаα-Pr(Ga-In) = 5.866 - 14766/T ± 0.190. lgγα-Pr(Ga-In) = 2.351 - 9996/T ± 0.39. lgХPr(Ga-In) = 3.515 - 4770/T ± 0.20.

  6. Dysprosium, holmium and erbium ions doped indium oxide nanotubes as photoanodes for dye sensitized solar cells and improved device performance.

    PubMed

    Miao, Chuang; Chen, Cong; Dai, Qilin; Xu, Lin; Song, Hongwei

    2015-02-15

    In this work, rare earth (RE) ion RE(3+) (RE(3+)=Dy(3+), Ho(3+) and Er(3+)) doped and undoped In2O3 nanotubes are synthesized by the electrospinning method and the band gap of In2O3 is systemically controlled, depending on the order of doped elements. Dye-sensitized solar cells (DSSCs) based on In2O3:RE(3+) nanotubes are also fabricated, and significantly improved performance of In2O3-DSSC is observed due to the modulation of the band gap, larger recombination charge transfer resistance and longer electron lifetime. PMID:25460702

  7. Magnetoresistance and magnetic ordering in praseodymium and neodymium hexaborides

    SciTech Connect

    Anisimov, M. A.; Bogach, A. V.; Glushkov, V. V.; Demishev, S. V.; Samarin, N. A.; Filipov, V. B.; Shitsevalova, N. Yu.; Kuznetsov, A. V.; Sluchanko, N. E.

    2009-11-15

    The magnetoresistance {Delta}{rho}/{rho} of single-crystal samples of praseodymium and neodymium hexaborides (PrB{sub 6} and NdB{sub 6}) has been measured at temperatures ranging from 2 to 20 K in a magnetic field of up to 80 kOe. The results obtained have revealed a crossover of the regime from a small negative magnetoresistance in the paramagnetic state to a large positive magnetoresistive effect in magnetically ordered phases of the PrB{sub 6} and NdB{sub 6} compounds. An analysis of the dependences {Delta}{rho}(H)/{rho} has made it possible to separate three contributions to the magnetoresistance for the compounds under investigation. In addition to the main negative contribution, which is quadratic in the magnetic field (-{Delta}{rho}/{rho} {proportional_to} H{sup 2}), a linear positive contribution ({Delta}{rho}/{rho} {proportional_to} H) and a nonlinear ferromagnetic contribution have been found. Upon transition to a magnetically ordered state, the linear positive component in the magnetoresistance of the PrB{sub 6} and NdB{sub 6} compounds becomes dominant, whereas the quadratic contribution to the negative magnetoresistance is completely suppressed in the commensurate magnetic phase of these compounds. The presence of several components in the magnetoresistance has been explained by assuming that, in the antiferromagnetic phases of PrB{sub 6} and NdB{sub 6}, ferromagnetic nanoregions (ferrons) are formed in the 5d band in the vicinity of the rareearth ions. The origin of the quadratic contribution to the negative magnetoresistance is interpreted in terms of the Yosida model, which takes into account scattering of conduction electrons by localized magnetic moments of rare-earth ions. Within the approach used, the local magnetic susceptibility {chi}{sub loc} has been estimated. It has been demonstrated that, in the temperature range T{sub N} < T < 20 K, the behavior of the local magnetic susceptibility {chi}{sub loc} for the compounds under investigation can

  8. Resonance ionization of holmium for ion implantation in microcalorimeters

    NASA Astrophysics Data System (ADS)

    Schneider, F.; Chrysalidis, K.; Dorrer, H.; Düllmann, Ch. E.; Eberhardt, K.; Haas, R.; Kieck, T.; Mokry, C.; Naubereit, P.; Schmidt, S.; Wendt, K.

    2016-06-01

    The determination of the electron neutrino mass by calorimetric measurement of the 163 Ho electron capture spectrum requires ultra-pure samples. Several collaborations, like ECHo or HOLMES, intend to employ microcalorimeters into which 163 Ho is implanted as an ion beam. This makes a selective and additionally very efficient ion source for holmium mandatory. For this purpose, laser resonance ionization of stable holmium 165 Ho was studied, using a three step excitation scheme driven by pulsed Ti:sapphire lasers. Five measurements with sample sizes of 1014 and 1015 atoms were performed for the efficiency investigation. In average, an excellent ionization efficiency of 32(5) % could be shown, demonstrating the suitability for ion beam implantation.

  9. Standard thermodynamic functions and Gibbs energy of holmium tungstenates

    SciTech Connect

    Nadiradze, A.A.; Gvelesiani, G.G.; Abashidze, T.D.; Makharadze, I.A.

    1986-12-01

    The Gibbs free energy of meta- and normal holmium tungstenates was studied by the emf method with the solid oxygen-ion electrolyte. The standard values of the entropy and enthalpy of formation of holmium tungstenates Ho/sub 6/WO/sub 12/, Ho/sub 10/W/sub 2/O/sub 21/, Ho/sub 14/W/sub 4/O/sub 33/, Ho/sub 2/WO/sub 6/, and Ho/sub 2/(WO/sub 4/)/sub 3/ were calculated. Three-term equations for the Gibbs energy of formation of the indicated tungstenates from the oxides for a wide temperature range were constructed. It was shown that the values of the standard atomic entropies and enthalpies of formation of these compounds decrease as their WO/sub 3/ content increases.

  10. Development of high-power holmium-doped fibre amplifiers

    NASA Astrophysics Data System (ADS)

    Hemming, Alexander; Simakov, Nikita; Davidson, Alan; Oermann, Michael; Corena, Len; Stepanov, Dmitrii; Carmody, Neil; Haub, John; Swain, Robert; Carter, Adrian

    2014-03-01

    Resonantly pumped holmium fibre lasers present a range of opportunities for the development of novel fibre laser and amplifier devices due to the availability of mature, efficient high power thulium fibre pump lasers. In this paper we describe the operation of a large mode area holmium-doped fibre amplifier. The master-oscillator is an all-fibre linearly polarised, core pumped single mode laser operating at 27 W at 2.11 μm. This laser was amplified in a large mode area fibre producing up to 265 W of output power. This system is the first demonstration of a resonantly pumped holmiumdoped fibre amplifier. It is also the highest power fibre amplifier that is capable of operating in an atmospheric transmission window <2.05 μm. This monolithic all-fibre system is able to address a wide range of remote sensing, scientific, medical and defence applications.

  11. Hard and fragile holmium-based bulk metallic glasses

    SciTech Connect

    Luo, Q.; Zhao, D.Q.; Pan, M.X.; Wang, R.J.; Wang, W.H.

    2006-05-01

    A family of holmium-based bulk metallic glasses (BMGs) with high glass-forming ability is obtained. The Ho-based BMGs exhibit much larger elastic moduli and high thermal stability in contrast to other known rare-earth (RE)-based BMGs. In particular, the BMGs show a large value of fragility. It is expected that the hard RE-based glasses with high glass-forming ability and fragile behaviors make them the appropriate candidate for glass transition study.

  12. Holmium YAG laser treatment of superficial bladder carcinoma.

    PubMed

    Hossain, M Z; Khan, S A; Salam, M A; Hossain, S; Islam, R

    2005-01-01

    Holmium YAG laser is one of the new modalities of treatment of urinary bladder tumor. Thirty patients of superficial bladder carcinoma were selected from the Urology out patient department of Dhaka Medical College Hospital from January 2004 to July 2004. Among thirty cases, 18 were recurrent and 12 were primary superficial bladder carcinoma. Out of thirty patients, 24 were male and six were female. Patients were treated with Holmium YAG laser under spinal anesthesia. Before resection, cold cup biopsy were taken from the apex and after resection of the tumor, another cold cup biopsy were taken from the base of the tumor. Holmium YAG laser therapy was given with a 550 micron end firing quartz laser fiber through the working element of resectoscope. Small tumors (< 1 cm) were ablated and large tumors (1-4 cm) were resected. The initial laser setting was 0.5 to 0.8 J and 10 Hz. For resection of the tumor, a slightly higher energy of 1 to 1.2 J was used at 10 to 12 Hz. After resection, bleeding vessels were coagulated. The resected tumor was evacuated by Elik's evacuator. All cases were followed for 6 to 12 months by history, physical examination, urine analysis, sonogram and cystoscopy three monthly. Bleeding was minimum during the procedure and no transfusion was required. Complications like obturator jerk, clot retention or perforation were not developed. No recurrence was found during the 6 to 12 months follow up period. The procedure was found safe, effective, and acceptable. The study was conducted to evaluate the initial result of Holmium YAG laser for the treatment of superficial bladder carcinoma. We warrants further studies in this regard. PMID:15695945

  13. The structure of rare earth thin films: holmium and gadolinium on yttrium

    NASA Astrophysics Data System (ADS)

    Bentall, M. J.; Cowley, R. A.; Ward, R. C. C.; Wells, M. R.; Stunault, A.

    2003-11-01

    Single-crystal holmium and gadolinium layers have been grown on yttrium substrates using the molecular beam epitaxy technique and their structures investigated using high resolution x-ray scattering. The experiments were performed using a Philips MRD diffractometer in Oxford, and with the XMaS facility at the ESRF. Holmium layers with a thickness below T_{\\mathrm {c}}'=115\

  14. Experimental studies on the usage possibilities of the holmium laser in cataract surgery

    NASA Astrophysics Data System (ADS)

    Kecik, Tadeusz; Kecik, Dariusz; Kasprzak, Jan; Pratnicki, Antoni; Jankiewicz, Zdzislaw; Zajac, Andrzej

    1996-03-01

    The authors present initial investigations of used holmium laser during experimental cataract surgery. The investigations were performed 'in vitro' and 'in vivo.' The presented results of the experiments show that structure of the lens can be emulsified with the use of the holmium laser.

  15. Microstructural Features in Aged Erbium Tritide Foils

    SciTech Connect

    Gelles, David S.; Brewer, L. N.; Kotula, Paul G.; Cowgill, Donald F.; Busick, C. C.; Snow, C. S.

    2008-01-01

    Aged erbium tritide foil specimens are found to contain five distinctly different microstructural features. The general structure was of large columnar grains of ErT2. But on a fine scale, precipitates believed to be erbium oxy-tritides and helium bubbles could be identified. The precipitate size was in the range of ~10 nm and the bubbles were of an unusual planar shape on {111} planes with an invariant thickness of ~1 nm and a diameter on the order of 10 nm. Also, an outer layer containing no fine precipitate structure and only a few helium bubbles was present on foils. This layer is best described as a denuded zone which probably grew during aging in air. Finally, large embedded Er2O3 particles were found at low density and non-uniformly distributed, but sometimes extending through the thickness of the foil. A failure mechanism allowing the helium to escape is suggested by observed cracking between bubbles closer to end of life.

  16. Erbium laser resurfacing for actinic cheilitis.

    PubMed

    Cohen, Joel L

    2013-11-01

    Actinic cheilitis is a precancerous condition characterized by grayish-whitish area(s) of discoloration on the mucosal lip, often blunting the demarcation between mucosa and cutaneous lip. Actinic cheilitis is considered to be an early part of the spectrum of squamous cell carcinoma. Squamous cell carcinoma specifically of the lip has a high rate of recurrence and metastasis through the oral cavity leading to a poor overall survival. Risk factors for the development of actinic cheilitis include chronic solar irradiation, increasing age, male gender, light skin complexion, immunosuppression, and possibly tobacco and alcohol consumption. Treatment options include topical pharmacotherapy (eg, fluorouracil, imiquimod) or procedural interventions (eg, cryotherapy, electrosurgery, surgical vermillionectomy, laser resurfacing), each with their known advantages and disadvantages. There is little consensus as to which treatment options offer the most clinical utility given the paucity of comparative clinical data. In my practice, laser resurfacing has become an important tool for the treatment of actinic cheilitis owing to its ease of use and overall safety, tolerability, and cosmetic acceptability. Herein the use of erbium laser resurfacing is described for three actinic cheilitis presentations for which I find it particularly useful: clinically prominent actinic cheilitis, biopsy-proven actinic cheilitis, and treatment of the entire lip following complete tumor excision of squamous cell carcinoma. All patients were treated with a 2940-nm erbium laser (Sciton Profile Contour Tunable Resurfacing Laser [TRL], Sciton, Inc., Palo Alto, CA). PMID:24196339

  17. Optical Frequency Comb Generation based on Erbium Fiber Lasers

    NASA Astrophysics Data System (ADS)

    Droste, Stefan; Ycas, Gabriel; Washburn, Brian R.; Coddington, Ian; Newbury, Nathan R.

    2016-06-01

    Optical frequency combs have revolutionized optical frequency metrology and are being actively investigated in a number of applications outside of pure optical frequency metrology. For reasons of cost, robustness, performance, and flexibility, the erbium fiber laser frequency comb has emerged as the most commonly used frequency comb system and many different designs of erbium fiber frequency combs have been demonstrated. We review the different approaches taken in the design of erbium fiber frequency combs, including the major building blocks of the underlying mode-locked laser, amplifier, supercontinuum generation and actuators for stabilization of the frequency comb.

  18. Delivery of Erbium:YAG laser radiation through side-firing germanium oxide optical fibers

    NASA Astrophysics Data System (ADS)

    Ngo, Anthony K.; Fried, Nathaniel M.

    2006-02-01

    The Erbium:YAG laser is currently being tested experimentally for endoscopic applications in urology, including more efficient laser lithotripsy and more precise incision of urethral strictures than the Holmium:YAG laser. While side-firing silica fibers are available for use with the Ho:YAG laser in urology, no such fibers exist for use with the Er:YAG laser. These applications may benefit from the availability of a side-firing, mid-infrared optical fiber capable of delivering the laser radiation at a 90-degree angle to the tissue. The objective of this study is to describe the simple construction and characterization of a side-firing germanium oxide fiber for potential use in endoscopic laser surgery. Side-firing fibers were constructed from 450-micron-core germanium oxide fibers of 1.45-m-length by polishing the distal tip at a 45-degree angle and placing a 1-cm-long protective quartz cap over the fiber tip. Er:YAG laser radiation with a wavelength of 2.94 microns, pulse duration of 300 microseconds, pulse repetition rate of 3 Hz, and pulse energies of from 5 to 550 mJ was coupled into the fibers. The fiber transmission rate and damage threshold measured 48 +/- 4 % and 149 +/- 37 mJ, respectively (n = 6 fibers). By comparison, fiber transmission through normal germanium oxide trunk fibers measured 66 +/- 3 %, with no observed damage (n = 5 fibers). Sufficient pulse energies were transmitted through the side-firing fibers for contact tissue ablation. Although these initial tests are promising, further studies will need to be conducted, focusing on assembly of more flexible, smaller diameter fibers, fiber bending transmission tests, long-term fiber reliability tests, and improvement of the fiber output spatial beam profile.

  19. Buckshot colic: utilizing holmium:yag laser for ureteroscopic removal of a bullet fragment within the proximal ureter.

    PubMed

    Ziegelmann, Matthew; Carrasco, Alonso; Knoedler, John; Krambeck, Amy E

    2016-06-01

    Buckshot colic is a rare phenomenon, presenting as firearm-induced urinary tract obstruction. We present a case of gunshot-induced ureteral obstruction in a 49-year-old male, treated endoscopically with the holmium:YAG (holmium) laser. CT revealed a 1 cm bullet fragment within the left proximal ureter. A percutaneous nephrolithotomy was performed utilizing the holmium laser to fragment the metal into basket-retrievable pieces. At 4 month follow up the patient is without evidence of stricture. To our knowledge, this is the first reported utilization of the holmium laser to treat "buckshot colic". Endoscopy with holmium laser appears a feasible and safe treatment option. PMID:27347630

  20. Investigation of Praseodymium Fluorides: A Combined Matrix-Isolation and Quantum-Chemical Study.

    PubMed

    Vent-Schmidt, Thomas; Riedel, Sebastian

    2015-12-01

    The chemistry of the lanthanides is mostly dominated by compounds in the oxidation state +III. Only few compounds of Ce, Pr, and Tb are known with the metal in the +IV oxidation state. Removal of the last f-electron on praseodymium +IV would lead to a closed-shell system with formal oxidation state V. In this work we investigated the stability of the PrF5 molecule by theory and matrix-isolation techniques through the reaction of laser-ablated praseodymium atoms with fluorine in excess of neon, argon, krypton, or neat fluorine. Besides the known PrF3 molecule, unreported IR bands for PrF4 could be observed, and there is evidence for the formation of PrF and PrF2 but not for the formation of PrF5. PMID:26544761

  1. Lanthanum(III) and praseodymium(III) derivatives with dithiocarbamates derived from α-amino acids

    NASA Astrophysics Data System (ADS)

    Rai, Anita; Sengupta, Soumitra K.; Pandey, Om P.

    2006-06-01

    Lanthanum(III) and praseodymium(III) complexes with dithiocarbamates have been synthesized by the reactions of lanthanum(III) and praseodymium(III) chloride with barium dithiocarbamate and complexes of type [LnCl(L)H 2O] n have been obtained (where Ln = La(III) or Pr(III); L = barium salt of dithiocarbamate derived from glycine, L-leucine, L-valine, DL-alanine). The complexes have been characterized by elemental analysis, molar conductance, electronic absorption and fluorescence, infrared, far infrared, 1H NMR spectral studies. The presence of coordinated water molecule is inferred from thermogravimetric analysis which indicates the loss of one water molecule at 150-170 °C. The oscillator strength, Judd-Ofelt intensity parameter, stimulated emission cross-section, etc. have been obtained for different transitions of Pr 3+.

  2. High-Resolution Spectroscopy of K-shell Praseodymium with a High-Energy Calorimeter

    SciTech Connect

    Thorn, D B; Brown, G V; Clementson, J T; Chen, H; Chen, M H; Beiersdorfer, P; Boyce, K R; Kilbourne, C A; Porter, F S; Kelley, R L

    2007-06-05

    We present a measurement of the K-shell spectrum of He-like through Be-like praseodymium ions trapped in the Livermore SuperEBIT electron beam ion trap using a bismuth absorber pixel on the XRS/EBIT microcalorimeter. This measurement is the first of its kind where the n=2 to n=1 transitions of the various charge states are spectroscopically resolved. The measured transition energies are compared with theoretical calculations from several atomic codes.

  3. Size control of erbium-doped silicon nanocrystals

    NASA Astrophysics Data System (ADS)

    John, John St.; Coffer, Jeffery L.; Chen, Yandong; Pinizzotto, Russell F.

    2000-09-01

    This work describes the effects of pyrolysis oven length and erbium precursor on the preparation of discrete erbium-doped silicon nanoparticles. These doped nanoparticles were prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd)3 (tmhd=2,2,6,6-tetramethyl-3,5-heptanedionato). The particle sizes and size distributions were determined using high resolution and conventional transmission electron microscopy. Erbium-doped silicon nanoparticles exhibit a selected area electron diffraction pattern consistent with the diamond cubic phase and a distinctive dark contrast in the transmission electron microscope. The presence of erbium is confirmed by x-ray energy dispersive spectroscopy. In general, the mean diameter of the individual nanoparticles increases as the length of the pyrolysis oven used during their preparation is increased.

  4. Age hardening and creep resistance of cast Al–Cu alloy modified by praseodymium

    SciTech Connect

    Bai, Zhihao; Qiu, Feng; Wu, Xiaoxue; Liu, Yingying; Jiang, Qichuan

    2013-12-15

    The effects of praseodymium on age hardening behavior and creep resistance of cast Al–Cu alloy were investigated. The results indicated that praseodymium facilitated the formation of the θ′ precipitates during the age process and improved the hardness of the Al–Cu alloy. Besides, praseodymium resulted in the formation of the Al{sub 11}Pr{sub 3} phase in the grain boundaries and among the dendrites of the modified alloy. Because of the good thermal stability of Al{sub 11}Pr{sub 3} phase, it inhibits grain boundary migration and dislocation movement during the creep process, which contributes to the improvement in the creep resistance of the modified alloy at elevated temperatures. - Highlights: • Pr addition enhances the hardness and creep resistance of the Al–Cu alloy. • Pr addition facilitates the formation of the θ′ precipitates. • Pr addition results in the formation of the Al11Pr3 phase in the Al–Cu alloy.

  5. Luminescence of erbium ions in tellurite glasses

    SciTech Connect

    Savikin, Alexander P.; Grishin, Igor A.; Sharkov, Valery V.; Budruev, Andrei V.

    2013-11-15

    Optical characteristics of new generation of tellurite glasses having high stability against crystallization have been studied. As the initial reagents for the glasses synthesis on the base of tellurium oxide (TeO{sub 2}) there were used such oxides as WO{sub 3}, MoO{sub 3}, La{sub 2}O{sub 3}, Li{sub 2}CO{sub 3}, ZnO—Bi{sub 2}O{sub 2}CO{sub 3} and active components such as high purity Er{sub 2}O{sub 3}, Yb{sub 2}O{sub 3}, ErF{sub 3} and YbF{sub 3}. Intensities of luminescence at 1.53 µm of the erbium ions were determined after excitation at 975 nm. Experimental data obtained have shown the possibility to use the studied glasses doped by Er{sup 3+} and Yb{sup 3+} as active elements for fiber and integrated optics. - Graphical abstract: In contrast to the case of ZBLAN glass the TeO{sub 2}–WO{sub 3} (Er{sup 3+}) glass has bright intensity of luminescence at 1.53 µm for erbium ions that should be caused by excitation at 975 nm. Experimental data obtained have shown the possibility to use the studied glasses doped by Er{sup 3+} and Yb{sup 3+} as active elements for fiber and integrated optics. Display Omitted - Highlights: • We examined changes in growth of luminescence in doubly-doped tellurite glasses. • We found that luminescence grows in two orders by using Er{sup 3+} and Yb{sup 3+} at 1.53 μm. • We see possibility to use those glasses as active elements for integrated optics.

  6. Intracorporeal lithotripsy with the holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    A variety of devices are currently available for intracorporeal stone fragmentation. Recently a new wavelength of laser, the Holmium:YAG, has demonstrated a variety of potential urologic applications including ablation of soft tissue lesions as well as stone fragmentation. This laser has a wavelength of 2100 nm and operates in a pulsed mode. Energy is delivered through a 400 um quartz end-firing fiber. In this presentation we review our clinical experience with the Holmium:YAG laser for the treatment of renal and ureteral calculi. Over a 23 month period, 63 patients underwent 67 procedures. Seven procedures consisted of percutaneous nephrolithotripsy for large or staghorn renal calculi. Sixty procedures were performed for ureteral stones. Procedures for proximal ureteral stones (6) employed a retrograde approach using flexible ureteroscopes (8.5 or 9.8). Stones in the mid ureter (12) and distal ureter (42) were approached transurethrally using a 6.9 rigid ureteroscope. Complete stone fragmentation without the need for additional procedures was achieved in 82% of cases. Treatment failures included 1 stone migration into the renal pelvis during laser activation, 6 patients who had incomplete fragmentation and 3 patients in which laser malfunction precluded complete fragmentation. Stone analysis available in 23 patients revealed calcium oxalate monohydrate (15), calcium oxalate dihydrate (2), cystine (2), uric acid (3) and calcium phosphate (1). A single complication of ureteral perforation occurred when the laser was fired without direct visual guidance. Radiographic follow-up at an average of 16 weeks is available in 22 patients and has identified 2 patients with ureteral strictures that are not believed to be related to laser lithotripsy. In summary, we have found the Holmium:YAG laser to be a reliable and versatile device for intracorporeal lithotripsy. Its safety and efficacy make it a suitable alternative for performing intracorporeal lithotripsy of urinary

  7. Holmium laser lithotripsy for ureteral calculi: an outpatient procedure.

    PubMed

    Yip, K H; Lee, C W; Tam, P C

    1998-06-01

    A retrospective review was conducted to evaluate the efficacy of ureteroscopic lithotripsy using the holmium laser with a semirigid endoscope in a newly established day surgery center. In 1996, 69 consecutive patients (40 male and 29 female) with a mean age of 46.7 (range 21-73) years and ASA status I or II underwent ureteroscopic lithotripsy for their ureteral calculi using the holmium laser (365-micron fiber; power setting 0.5-1.4 J/5 Hz) and 8.5F semirigid ureteroscope in a day surgery setting. Stone features, postoperative pain scores, readmissions, and complications were evaluated. Eighteen upper, 17 middle, and 34 lower ureteral stones were treated, with a mean size measuring 12.1 (5-45) mm. The mean operative time was 61 minutes including the anesthetic time (range 15-150 minutes), and the success rate was 91% (63/69). The complication rate was 10% (7/69) including four unscheduled readmissions (6%). Telephone follow-up on postoperative Day 1 and Day 3 revealed mean pain scores of 2 and 1, respectively (on a 0-10 scale) and an analgesic requirement of 1 tablet of Dologesic (containing 32.5 mg of dextropropoxyphene + 320 mg of paracetamol) four times a day on both days. Ureteroscopic lithotripsy using the holmium laser and a semirigid endoscope is highly successful and well tolerated and carries a low complication rate. It is indicated as an ambulatory and minimally invasive treatment modality in low-risk patients with ureteral stones. PMID:9658294

  8. Drug metabolism: Comparison of biodistribution profile of holmium in three different compositions in healthy Wistar rats.

    PubMed

    Cerqueira-Coutinho, Cristal; Vidal, Lluis Pascual; Pinto, Suyene Rocha; Santos-Oliveira, Ralph

    2016-06-01

    Radioisotope holmium is a candidate to be used in cancer treatment and diagnosis. There are different holmium salts and they present distinct solubility and consequently different biodistribution profiles. In this work, we aimed to evaluate the biodistribution profiles of two holmium salts (chloride and sulfate) and holmium nanoparticles (oxide) through an in vivo biodistribution assay using animal model. Samples were labeled with technetium-99m and administered in Wistar rats by retro-orbital route. Holmium chloride is highly soluble in water and it was quickly filtered by the kidneys while holmium sulfate that presents lower solubility in water was mainly found in the liver and the spleen. However, both the salts showed a similar biodistribution profile. On the other hand, holmium oxide showed a very different biodistribution profile since it seemed to interact with all organs. Due to its particle size range (approximately 100nm) it was not intensively filtered by the kidneys being found in high quantities in many organs, for this reason its use as a nanoradiopharmaceutical could be promising in the oncology field. PMID:26986812

  9. The studies on the aromaticity of fullerenes and their holmium endohedral compounds.

    PubMed

    Tan, Bisheng; Peng, Rufang; Li, Hongbo; Wang, Bing; Jin, Bo; Chu, Shijin; Long, Xinping

    2011-02-01

    Density functional theory BLYP/DNP was employed to optimize a series of fullerenes and their holmium endohedral compounds, including C(20), Ho@C(20), Ho(3+)@C(20), C(60), Ho@C(60), Ho(3+)@C(60),C(70), Ho@C(70), Ho(3+)@C(70) C(78), Ho@C(78), Ho(3+)@C(78), C(82),Ho@C(82) and Ho(3+)@C(82). DFT semi core pseudospot approximation was taken into consideration in the calculations of the element holmium because of its particular electronic structure. Fullerenes and their holmium endohedral compounds' aromaticity were studied in terms of structural criteria, energetic criteria, and reactivity criteria. The results indicate that the aromaticity of fullerenes was reduced when a holmium atom was introduced into the carbon cage, and the endohedral fullerenes' reactive activity enhance; but the aromaticity of the carbon cage increased when a Ho(3+) cation was encapsulated into a fullerene. Calculations of aromaticity and stability indicate that two paths can lead to the similar aim of preparing holmium endohedral fullerenes; that is, they can form from either a holmium atom or a holmium cation (Ho(3+)) reacting with fullerenes, respectively, and the latter is more favorable. PMID:20443036

  10. Role of temperature in the theoretical analysis of holmium pnictides

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Purvee; Singh, Sadhna

    2016-01-01

    The high-pressure structural phase transition and associated properties of holmium pnictides (HoX; X = P, As, Sb and Bi) have been investigated in the present work. The Realistic Interaction Potential Approach (RIPA) including the effect of temperature has been applied. The occurrence of first order phase transition is evidenced from a sudden collapse in volume. These compounds transform from B1 to B2 structure under high pressure. The high temperature and pressure behaviour of elastic constants and bulk modulus are also reported. Our results are in general in good agreement with experimental and other theoretical results where available, and provide predictions where they are unavailable.

  11. Treatment of pulmonary diseases with Holmium:YAG laser

    NASA Astrophysics Data System (ADS)

    Zhang, Mei-Jue; Zhu, Jing; Zhang, Hui-Guo; Wang, Fu-Juan; Ke, Lin; Ma, Wei; Luo, Qun-Hua; Zhang, Yue-E.

    1998-11-01

    We report 5 cases of pulmonary disease treated with Holmium:YAG laser through fibrous bronchoscope. 1 inflammatory granuloma was cured after three times of treatment. Compared with conventional methods such as electrocautery and microwave treatment, laser has the merit of good hemostasis effect and quick recovery of the operation area. The other 4 patients who were suffered late lung cancer received 3-7 times of palliative treatment. After the treatment, the tumor tissues become smaller variably, and tact were unobstructed, symptoms of tract- obstructed obviously alleviated. We think that laser treatment has some practical significance in alleviating tract blocking of pulmonary diseases of late stage, and therefore raise the life quality.

  12. Erbium Doped Fiber Sources and Amplifiers for Optical Fiber Sensors.

    NASA Astrophysics Data System (ADS)

    Wagener, Jefferson L.

    1996-08-01

    This thesis explores the use of erbium-doped fiber in lasers, amplified spontaneous emission sources, and amplifiers with particular attention to applications involving fiber sensor technology. Erbium-doped fiber laser output power is shown to be strongly dependent on the erbium dopant concentration in a fiber. Using multiple fibers with various erbium ion concentrations, laser output powers are found to decrease as erbium concentration is increased. Upconversion in paired ions is successfully used to model the lasers, resulting in a better understanding of the loss mechanism involved. Further investigation shows that co-doping an erbium-doped fiber with aluminum helps eliminate upconversion in paired ions, and an optimum ratio of 20 aluminum ions for every erbium ion is established. Upconversion due to paired ions is also used to predict the behavior of erbium-doped fiber amplifiers as a function of the erbium ion concentration. With this knowledge of concentration dependence, a low doped, high output power fiber is chosen for use as an amplified spontaneous emission source in a fiber optic gyroscope. Used as a single pass broadband source in one propagation direction and as a signal amplifier in the other direction, this source is tested experimentally in a high quality fiber gyroscope. Experimental results reveal an unexpected dependence on the polarization states of the optical pump and the gyroscope output signal. A theory of polarization anisotropy in the erbium ions is developed in full and accurately models the experimental observations. Using this model to optimize the source, a fiber gyroscope output stability of 4 parts per million is obtained experimentally, approaching the requirements of inertial navigation. This model is also used to explore novel single polarization amplified spontaneous emission sources. Large scale amplified sensor arrays are examined theoretically to determine component and amplification requirements. For balanced gain and loss

  13. Holmium Nitrate Complexation with Tri-n-butyl Phosphate in Supercritical Carbon Dioxide

    SciTech Connect

    Robert V. Fox; R. Duane Ball; Peter de B. Harrington; Harry W. Rollins; Chien M. Wai

    2005-12-01

    Holmium nitrate pentahydrate was reacted with tri-n-butyl phosphate in supercritical carbon dioxide at 308 K. The products of the complexation reaction were measured under supercritical fluid conditions using UV-vis spectroscopy. The solubility of the metal complexes in the supercritical fluid phase was measured. The mole-ratio titration method was used to determine the stoichiometry of the soluble complexes. Conditional extraction coefficients were calculated from spectral data using least-squares regression and hard-equilibria models. Data indicate that the holmium nitrate-tributyl phosphate system forms 1:2 and 1:4 holmium-tributyl phosphate complexes.

  14. Effect of the active-ion concentration on the lasing dynamics of holmium fibre lasers

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-12-09

    The lasing dynamics of fibre lasers with a core based on quartz glass doped with holmium ions to concentrations in the range of 10{sup 19}-10{sup 20} cm{sup -3} is investigated. It is shown that fibre lasers with a high concentration of active holmium ions generate pulses, but a decrease in the holmium concentration changes the lasing from pulsed to cw regime. At the same time, a decrease in the active-ion concentration and the corresponding increase in the fibre length in the cavity reduce the lasing efficiency. (lasers)

  15. Effect of active-ion concentration on holmium fibre laser efficiency

    SciTech Connect

    Kurkov, Andrei S; Sholokhov, E M; Marakulin, A V; Minashina, L A

    2010-08-03

    We have measured the fraction of holmium ions that relax nonradiatively to the ground level as a result of interaction at a metastable level in optical fibres with a silica-based core doped with holmium ions to 2 x 10{sup 19} - 2 x 10{sup 20} cm{sup -3}. The percentage of such ions has been shown to depend on the absolute active-ion concentration. The fibres have been used to make a number of 2.05-{mu}m lasers, and their slope efficiency has been measured. The laser efficiency decreases with increasing holmium concentration in the fibres (lasers)

  16. Holmium:YAG laser angioplasty: treatment of acute myocardial infarction

    NASA Astrophysics Data System (ADS)

    Topaz, On

    1993-06-01

    We report our clinical experience with a group of 14 patients who presented with acute myocardial infarction. A holmium:YAG laser was applied to the infarct-related artery. This laser emits 250 - 600 mJ per pulse, with a pulse length of 250 microseconds and repetition rate of 5 Hz. Potential benefits of acute thrombolysis by lasers include the absence of systemic lytic state; a shortened thrombus clearing time relative to using thrombolytics; safe removal of the intracoronary thrombus and facilitation of adjunct balloon angioplasty. Potential clinical difficulties include targeting the obstructive clot and plaque, creation of debris and distal emboli and laser-tissue damage. It is conceivable that holmium:YAG laser can be a successful thrombolytic device as its wave length (2.1 microns) coincides with strong water absorption peaks. Since it is common to find an atherosclerotic plaque located under or distal to the thrombotic occlusion, this laser can also be applied for plaque ablation, and the patient presenting with acute myocardial infarction can clearly benefit from the combined function of this laser system.

  17. Dielectric and conducting behaviour of polycrystalline holmium octa-molybdate

    NASA Astrophysics Data System (ADS)

    Want, Basharat; Zahoor Ahmad, Bhat; Bhat, Bilal Hamid

    2014-09-01

    Polycrystalline holmium octa-molybdate spherulites have been obtained by using gel diffusion technique and characterized by different physio-chemical techniques. The surfaces of these spherulites are composed of nano-rod with an average diameter of about 80 nm. At room temperature the initial crystal structure is triclinic, space group P1. Thermal studies suggested a phase transition occurring in holmium octa-molybdate crystals at about 793 K. The electrical properties of the system have been studied as a function of frequency and temperature in the ranges of 20 Hz-3 MHz and 290-570 K, respectively. A giant dielectric constant and two loss peaks have been observed in the permittivity formalism. The conducting behaviour of the material is also discussed. The conductivity was found to be 1572 μ Ω-1 m-1 at room temperature and 3 MHz frequency. The conductivity of the polycrystalline material was attributed to the fact that it arises due to the migration of defects on the oxygen sub-lattice. Impedance studies were also performed in the frequency domain to infer the bulk and grain boundary contributions to the overall electric response of the material. The electrical responses have been attributed to the grain, grain-boundary, and interfacial effects.

  18. Anodic behavior of alloys in the systems aluminum-scandium(yttrium, praseodymium, neodymium) in a neutral medium

    SciTech Connect

    Ganiev, I.N.; Yunusov, I.; Krasnoyarskii, V.V.

    1988-03-10

    The authors investigated the influence of scandium, yttrium, praseodymium, and neodymium on the anodic behavior of aluminum in a 3% sodium chloride solution by a potentiodynamic method which provided information over a time interval during which the state of the electrode surface and the composition of the solution remained essentially unchanged. Data were derived for electrochemical and pitting corrosion for different alloy contents and compositions. Results were analyzed for aluminum-scandium, aluminum-yttrium, aluminum-praseodymium, and aluminum-neodymium binary systems.

  19. Composition and method of treatment of arthritis and related diseases with holmium-166 radionuclides

    SciTech Connect

    Lieberman, E.; Bordoni, M.E.; Thornton, A.K.

    1991-10-29

    This patent describes a radioactive composition for the treatment of arthritis. It comprises a suspension containing particles having a minimum size of one micron, the suspension including particles containing holmium-166.

  20. Holmium laser use in the treatment of selected dry eye syndrome complications

    NASA Astrophysics Data System (ADS)

    Kecik, Dariusz; Kecik, Tadeusz; Kasprzak, Jan; Kecik, Mariusz

    1996-03-01

    The authors present initial results of treatment selected complications of dry eye syndrome with holmium laser. The lacrimal puncta obliteration and coagulation of the corneal ulcer surface were done.

  1. Holmium-doped fibre amplifier operating at 2.1 μm

    SciTech Connect

    Kamynin, V A; Antipov, S O; Kurkov, A S; Baranikov, A V

    2014-02-28

    A small-signal holmium-doped fibre amplifier is demonstrated. The seed source is a cw holmium-doped fibre laser whose output power is modulated by an electro-optical modulator. The maximum gain reached (wavelength, 2.1 μm; power, 0.25 mW; pulse duration, 100 ns; pulse repetition rate, 1 μs) is 28.5 dB. (lasers)

  2. Growth of praseodymium oxide on Si(111) under oxygen-deficient conditions

    SciTech Connect

    Schaefer, A.; Zielasek, V.; Baeumer, M.; Schmidt, Th.; Schowalter, M.; Schulz, Ch.; Rosenauer, A.; Falta, J.; Sandell, A.; Seifarth, O.; Schroeder, T.; Wollschlaeger, J.

    2009-07-15

    Surface science studies of thin praseodymium oxide films grown on silicon substrates are of high interest in view of applications in such different fields as microelectronics and heterogeneous catalysis. In particular, a detailed characterization of the growth and the final structure of the films are mandatory to achieve a fundamental understanding of such topics as oxygen mobility and defect structure, and their role for the electronic and chemical properties. In this paper, the MBE growth of praseodymium oxide films on Si(111) substrates was investigated at low-deposition rates (0.06 nm/min) and low-oxygen partial pressures (p(O{sub 2})<1x10{sup -10} mbar). To obtain insight into the structure and chemical composition of the growing film, spot profile analyzing low-energy electron diffraction (SPA-LEED), transmission electron microscopy, and synchrotron radiation-based x-ray photoelectron spectroscopy (XPS) and x-ray absorption spectroscopy (XAS) were applied. SPA-LEED reveals the formation of an initial closed layer followed by continuous roughening and formation of ordered three-dimensional structures. This result is in contrast to observations at higher-deposition rates, were a layer-by-layer growth was reported. XAS and XPS provide evidence that a continuous reaction takes place in the growing Pr{sub 2}O{sub 3} film leading to the formation of silicate and silicide structures within the film. Combining all data, a consistent picture of the deposition of praseodymium oxide on Si(111) emerges which clearly shows that in contrast to higher-throughput molecular beam epitaxy conditions the reactivity of the growing film strongly influences the growth behavior at low-deposition rates and low pressures.

  3. Activation of erbium films for hydrogen storage

    SciTech Connect

    Brumbach, Michael T.; Ohlhausen, James A.; Zavadil, Kevin R.; Snow, Clark S.; Woicik, Joseph C.

    2011-06-01

    Hydriding of metals can be routinely performed at high temperature in a rich hydrogen atmosphere. Prior to the hydrogen loading process, a thermal activation procedure is required to promote facile hydrogen sorption into the metal. Despite the wide spread utilization of this activation procedure, little is known about the chemical and electronic changes that occur during activation and how this thermal pretreatment leads to increased rates of hydrogen uptake. This study utilized variable kinetic energy X-ray photoelectron spectroscopy to interrogate the changes during in situ thermal annealing of erbium films, with results confirmed by time-of-flight secondary ion mass spectrometry and low energy ion scattering. Activation can be identified by a large increase in photoemission between the valence band edge and the Fermi level and appears to occur over a two stage process. The first stage involves desorption of contaminants and recrystallization of the oxide, initially impeding hydrogen loading. Further heating overcomes the first stage and leads to degradation of the passive surface oxide leading to a bulk film more accessible for hydrogen loading.

  4. Activatino of Erbium Films for Hydrogen Storage

    SciTech Connect

    M Brumbach; j Ohlhausen; K Zavadil; C Snow; J Woicik

    2011-12-31

    Hydriding of metals can be routinely performed at high temperature in a rich hydrogen atmosphere. Prior to the hydrogen loading process, a thermal activation procedure is required to promote facile hydrogen sorption into the metal. Despite the wide spread utilization of this activation procedure, little is known about the chemical and electronic changes that occur during activation and how this thermal pretreatment leads to increased rates of hydrogen uptake. This study utilized variable kinetic energy X-ray photoelectron spectroscopy to interrogate the changes during in situ thermal annealing of erbium films, with results confirmed by time-of-flight secondary ion mass spectrometry and low energy ion scattering. Activation can be identified by a large increase in photoemission between the valence band edge and the Fermi level and appears to occur over a two stage process. The first stage involves desorption of contaminants and recrystallization of the oxide, initially impeding hydrogen loading. Further heating overcomes the first stage and leads to degradation of the passive surface oxide leading to a bulk film more accessible for hydrogen loading.

  5. Erbium concentration dependent absorbance in tellurite glass

    SciTech Connect

    Sazali, E. S. Rohani, M. S. Sahar, M. R. Arifin, R. Ghoshal, S. K. Hamzah, K.

    2014-09-25

    Enhancing the optical absorption cross-section in topically important rare earth doped tellurite glasses is challenging for photonic devices. Controlled synthesis and detailed characterizations of the optical properties of these glasses are important for the optimization. The influence of varying concentration of Er{sup 3+} ions on the absorbance characteristics of lead tellurite glasses synthesized via melt-quenching technique are investigated. The UV-Vis absorption spectra exhibits six prominent peaks centered at 490, 526, 652, 800, 982 and 1520 nm ascribed to the transitions in erbium ion from the ground state to the excited states {sup 4}F{sub 7/2}, {sup 2}H{sub 11/2}, {sup 4}F{sub 9/2}, {sup 4}I{sub 9/2}, {sup 2}H{sub 11/2} and {sup 4}I{sub 13/2}, respectively. The results are analyzed by means of optical band gap E{sub g} and Urbach energy E{sub u}. The values of the energy band gap are found decreased from 2.82 to 2.51 eV and the Urbach energy increased from 0.15 to 0.24 eV with the increase of the Er{sub 2}O{sub 3} concentration from 0 to 1.5 mol%. The excellent absorbance of the prepared tellurite glasses makes them suitable for fabricating solid state lasers.

  6. Nanothermometry using optically trapped erbium oxide nanoparticle

    NASA Astrophysics Data System (ADS)

    Baral, Susil; Johnson, Samuel C.; Alaulamie, Arwa A.; Richardson, Hugh H.

    2016-04-01

    A new optical probe technique using a laser-trapped erbium oxide nanoparticle (size ~150 nm) is introduced that can measure absolute temperature with a spatial resolution on the size of the trapped nanoparticle. This technique (scanning optical probe thermometry) is used to collect a thermal image of a gold nanodot prepared with hole-mask colloidal lithography. A convolution analysis of the thermal profile shows that the point spread function of our measurement is a Gaussian with a FWHM of 165 nm. We attribute the width of this function to clustering of Er2O3 nanoparticles in solution. The scanning optical probe thermometer is used to measure the temperature where vapor nucleation occurs in degassed water (555 K), confirming that a nanoscale object heated in water will superheat the surrounding water to the spinodal decomposition temperature. Subsequently, the temperature inside the vapor bubble rises to the melting point of the gold nanostructure (~1300) where a temperature plateau is observed. The rise in temperature is attributed to inhibition of thermal transfer to the surrounding liquid by the thermal insulating vapor cocoon.

  7. Performance characteristics of a mode-locked erbium-doped fiber ring laser as a function of erbium ion concentration

    NASA Astrophysics Data System (ADS)

    Fanto, Michael L.; Gerhardstein, Cheryl M.; Vettese, E. K.; Winter, D. L.; Johns, Steven T.; Bussjager, Rebecca J.; Hayduk, Michael J.

    2003-07-01

    The generation of ultrastable picosecond pulses in the 1550 nm range is required for numerous applications including photonic analog-to-digital converter systems and high-bit rate optical communication systems. Mode-locked erbium-doped fiber ring lasers are typically used to generate pulses at this wavelength. In addition to stability and output power, the physical size of the laser cavity is of primary importance. The length of the erbium-doped fiber used as the gain medium may be on the order of meters or even tens of meters which makes packing of the laser rather difficult. However the length of the gain medium can often be reduced if the erbium ion concentration within the fiber is increased. This paper will investigate the performance of an erbium-doped fiber ring laser as a function of ion concentration within the gain medium. Results will be presented for mode-locked lasers consisting of Lucent HE980, HG980 and HC erbium-doped fibers. The parameters that will be compared between the lasers include the output power as a function of length and concentration, optical pulse width and spectral bandwidth. Phase noise measurements of the laser output will also be presented.

  8. Composition and structure of sputter deposited erbium hydride thin films

    SciTech Connect

    ADAMS,DAVID P.; ROMERO,JUAN A.; RODRIGUEZ,MARK A.; FLORO,JERROLD A.; BANKS,JAMES C.

    2000-05-10

    Erbium hydride thin films are grown onto polished, a-axis {alpha} Al{sub 2}O{sub 3} (sapphire) substrates by reactive ion beam sputtering and analyzed to determine composition, phase and microstructure. Erbium is sputtered while maintaining a H{sub 2} partial pressure of 1.4 x 10{sup {minus}4} Torr. Growth is conducted at several substrate temperatures between 30 and 500 C. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analyses after deposition show that the H/Er areal density ratio is approximately 3:1 for growth temperatures of 30, 150 and 275 C, while for growth above {approximately}430 C, the ratio of hydrogen to metal is closer to 2:1. However, x-ray diffraction shows that all films have a cubic metal sublattice structure corresponding to that of ErH{sub 2}. RBS and Auger electron that sputtered erbium hydride thin films are relatively free of impurities.

  9. Dipolar Physics in an Erbium Quantum Gas Microscope

    NASA Astrophysics Data System (ADS)

    Hebert, Anne; Krahn, Aaron; Phelps, Gregory; Dickerson, Susannah; Greiner, Markus; Erbium Lab Team

    2016-05-01

    Erbium offers exciting possibilities for extending the single-site imaging work of current quantum gas microscopes. With a magnetic dipole moment of 7μB, the dipole-dipole interaction of erbium is 50 times that of alkali atoms. The long-range and anisotropic nature of the dipole interaction adds richness to the short-range interactions that dominate the physics of the ground-state alkali atoms commonly used in ultracold experiments today. Erbium has several abundant isotopes, giving the added flexibility of studying both bosonic and fermionic systems. We present proposed avenues of research for the dipolar microscope being developed, including studies of magnetism, the Einstein-de Haas effect, and quantum phase transitions with fractional filling factors.

  10. Radiation-resistant erbium-doped silica fibre

    SciTech Connect

    Zotov, K V; Likhachev, M E; Tomashuk, A L; Bubnov, M M; Yashkov, M V; Gur'yanov, A N

    2007-10-31

    It is shown that the service life of erbium-doped fibres can be increased many times under conditions of an elevated radiation level by loading the fibre glass network with molecular hydrogen. Backdiffusion of hydrogen from the fibre in the process of its operation is virtually excluded for the fibre covered with a hermetic carbon coating. It is shown that this technique of fibre preparation allows one to slow down significantly degradation of the lasing properties of erbium fibres under the conditions characteristic of space applications. (special issue devoted to the 25th anniversary of the a.m. prokhorov general physics institute)

  11. Nonlinear optical responses of erbium-doped YAG ceramics

    NASA Astrophysics Data System (ADS)

    Sun, Wangliang; Yi, Jun; Miao, Lili; Li, Jiang; Xie, Tengfei; Zhao, Chujun; Pan, Yubai; Wen, Shuangchun

    2016-07-01

    By performing the Z-scan measurements with ultrafast femtosecond laser centered at 800 nm wavelength, we can unambiguously distinguish the real and imaginary part of the third-order optical nonlinearity of the erbium-doped YAG ceramics. The reverse saturable absorption of the erbium-doped YAG ceramics has been observed experimentally, and the nonlinear refractive index of the ceramics is estimated to be about 10-21 m2/W. The experimental results may provide design guidelines for the high power laser design and its applications.

  12. Metal-to-insulator transition in Y1-xPrxBa2Cu3O7-δ single crystals with various praseodymium contents

    NASA Astrophysics Data System (ADS)

    Vovk, R. V.; Nazyrov, Z. F.; Goulatis, I. L.; Chroneos, A.

    2013-02-01

    We investigate the influence of praseodymium content on the basis plane conductivity of Y1-хPrхBa2Cu3O7-δ single crystals. An increase of the praseodymium concentration leads to the enhancement of the localization effects and the appearance of a metal-insulator transition in the system, which always precedes the superconducting transition. The increase of the concentration of praseodymium, leads to a significant displacement of the point of the metal-insulator transition in the low temperature region.

  13. Energy upconversion in holmium doped lead-germano-tellurite glass

    SciTech Connect

    Kamma, Indumathi; Reddy, B. Rami

    2010-06-15

    Holmium doped lead-germano-tellurite glass was prepared by the melt quenching technique. The Judd-Ofelt intensity parameters were estimated as {Omega}{sub 2}=7.6x10{sup -20}, {Omega}{sub 4}=12.9x10{sup -20}, and {Omega}{sub 6}=2.5x10{sup -20} cm{sup 2}. Radiative transition probabilities and lifetimes were also determined for some of the levels. Room temperature upconversion emissions have been observed from Ho{sup 3+} at 497 nm under 532 nm laser excitation, and at 557 and 668 nm under 762 nm laser excitation. The upconversion emission mechanisms were found to be due to a step wise excitation process. Upconversion emission intensity enhanced in a heat treated glass.

  14. Controlling the physics and chemistry of binary and ternary praseodymium and cerium oxide systems.

    PubMed

    Niu, Gang; Zoellner, Marvin Hartwig; Schroeder, Thomas; Schaefer, Andreas; Jhang, Jin-Hao; Zielasek, Volkmar; Bäumer, Marcus; Wilkens, Henrik; Wollschläger, Joachim; Olbrich, Reinhard; Lammers, Christian; Reichling, Michael

    2015-10-14

    Rare earth praseodymium and cerium oxides have attracted intense research interest in the last few decades, due to their intriguing chemical and physical characteristics. An understanding of the correlation between structure and properties, in particular the surface chemistry, is urgently required for their application in microelectronics, catalysis, optics and other fields. Such an understanding is, however, hampered by the complexity of rare earth oxide materials and experimental methods for their characterisation. Here, we report recent progress in studying high-quality, single crystalline, praseodymium and cerium oxide films as well as ternary alloys grown on Si(111) substrates. Using these well-defined systems and based on a systematic multi-technique surface science approach, the corresponding physical and chemical properties, such as the surface structure, the surface morphology, the bulk-surface interaction and the oxygen storage/release capability, are explored in detail. We show that specifically the crystalline structure and the oxygen stoichiometry of the oxide thin films can be well controlled by the film preparation method. This work leads to a comprehensive understanding of the properties of rare earth oxides and highlights the applications of these versatile materials. Furthermore, methanol adsorption studies are performed on binary and ternary rare earth oxide thin films, demonstrating the feasibility of employing such systems for model catalytic studies. Specifically for ceria systems, we find considerable stability against normal environmental conditions so that they can be considered as a "materials bridge" between surface science models and real catalysts. PMID:26355535

  15. Characterization of the surface changes during the activation process of erbium/erbium oxide for hydrogen storage.

    SciTech Connect

    Zavadil, Kevin Robert; Snow, Clark Sheldon; Ohlhausen, James Anthony; Brumbach, Michael Todd

    2010-10-01

    Erbium is known to effectively load with hydrogen when held at high temperature in a hydrogen atmosphere. To make the storage of hydrogen kinetically feasible, a thermal activation step is required. Activation is a routine practice, but very little is known about the physical, chemical, and/or electronic processes that occur during Activation. This work presents in situ characterization of erbium Activation using variable energy photoelectron spectroscopy at various stages of the Activation process. Modification of the passive surface oxide plays a significant role in Activation. The chemical and electronic changes observed from core-level and valence band spectra will be discussed along with corroborating ion scattering spectroscopy measurements.

  16. Comparison of holmium:YAG and thulium fiber lasers for lithotripsy

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Irby, Pierce B.; Fried, Nathaniel M.

    2010-02-01

    The Holmium:YAG laser is currently the most common laser lithotripter. However, recent experimental studies have demonstrated that the Thulium fiber laser is also capable of vaporizing urinary stones. The high-temperature water absorption coefficient for the Thulium wavelength (μa = 160 cm-1 at λ = 1908 nm) is significantly greater than for the Holmium wavelength (μa = 28 cm-1 at λ = 2120 nm). We hypothesize that this should translate into more efficient laser lithotripsy using the Thulium fiber laser. This study directly compares stone vaporization rates for Holmium and Thulium fiber lasers. Holmium laser radiation pulsed at 3 Hz with 70 mJ pulse energy and 220 μs pulse duration was delivered through a 100-μm-core silica fiber to human uric acid (UA) and calcium oxalate monohydrate (COM) stones, ex vivo (n = 10 each). Thulium fiber laser radiation pulsed at 10 Hz with 70 mJ pulse energy and 1 ms pulse duration was also delivered through a 100-μm fiber for the same sets of 10 stones. For same number of pulses and total energy (126 J) delivered to each stone, mass loss averaged 2.4 +/- 0.6 mg (UA) and 0.7 +/- 0.2 mg (COM) for Holmium laser and 12.6 +/- 2.5 mg (UA) and 6.8 +/- 1.7 (COM) for Thulium fiber laser. UA and COM stone vaporization rates for Thulium fiber laser averaged 5-10 times higher than for Holmium laser at 70 mJ pulse energies. With further development, the Thulium fiber laser may represent an alternative to the conventional Holmium laser for more efficient laser lithotripsy.

  17. Preparation, fluorescence spectroscopy, and AFM analysis of erbium oxide nanocolloid

    NASA Astrophysics Data System (ADS)

    Patel, Darayas; Vance, Calvin; King, Newton; Jessup, Malcolm; Sarkisov, Sergey

    2009-02-01

    Nanocolloids of compounds containing fluorescent rare earth ions have recently attracted significant attention as agents for biolabeling, bioimaging, bio- and chemical sensing, and other applications. Erbium oxide nanocolloids have been prepared for the first time in water and gammabutyrolactone. Optical dynamic scatterometry and atomic force microscopy determined an average size (average mean height) of erbium oxide nanoparticles to be 10-11 nm. Prominent optical absorption peaks of the nanocolloids at 442.5 nm, 450.0 nm, 487.2 nm (strong), 492.0 nm, 523.0 nm (strong), 541.6 nm, 548.6 nm, 652.6 nm, and 665.7 nm (strong) can be attributed to erbium ions hosted within nanoparticles. Laser fluorescence spectroscopy of the nanocolloids was conducted using excitations with the lines of argon-ion laser (514 nm, 488 nm, 476 nm, and 458 nm) and 980-nm semiconductor laser. Strong green emission at 571 nm is more likely from transition between 4S3/2 and 4I15/2 levels and relatively weak red emissions from transition between 4I9/2 and 4I15/2 level of erbium was observed at excitation with visible laser radiation 488 nm and 476 nm. The reported nanocolloids thus showed to be good candidates for fluorescent biosensing applications and also as a new lasing filling medium in fiber lasers.

  18. Safety and efficacy of holmium:YAG laser lithotripsy in patients with bleeding diatheses

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Cook, Anthony J.; Beiko, Darren T.; Nott, Linda; Auge, Brian K.; Preminger, Glenn M.; Denstedt, John D.

    2003-06-01

    Purpose: To assess the safety and efficacy of ureteroscopy and holmium:YAG (yttrium-aluminum-garnet) laser lithotripsy in the treatment of upper urinary tract calculi in patients with known and uncorrected bleeding diatheses. Materials and Methods: A retrospective chart review from 2 tertiary stone centers was performed to identify patients with known bleeding diatheses who were treated with holmium:YAG laser lithotripsy for upper urinary tract calculi. Twenty-five patients with 29 upper urinary tract calculi were treated with ureteroscopic holmium laser lithotripsy. Bleeding diatheses identified were coumadin administration for various conditions (17), liver dysfunction (3), thrombocytopenia (4), and von Willebrand's disease (1). Mean international normalized ratio (INR), platelet count and bleeding time were 2.3, 50 x 109/L, and > 16 minutes, for patients receiving coumadin or with liver dysfunction, thrombocytopenia, or von Willebrand's disease, respectively. Results: Overall, the stone-free rate was 96% (27/28) and 29 of 30 procedures were completed successfully without significant complication. One patient who was treated concomitantly with electrohydraulic lithotripsy (EHL) had a significant retroperitoneal hemorrhage that required blood transfusion. Conclusions: Treatment of upper tract urinary calculi in patients with uncorrected bleeding diatheses can be safely performed using contemporary small caliber ureteroscopes and holmium laser as the sole modality of lithotripsy. Ureteroscopic holmium laser lithotripsy without preoperative correction of hemostatic parameters limits the risk of thromboembolic complications and costs associated with an extended hospital stay. Avoidance of the use of EHL is crucial in reducing bleeding complications in this cohort of patients.

  19. Evaluation of holmium laser for transurethral deroofing of severe and multiloculated prostatic abscesses

    PubMed Central

    Lee, Chan Ho; Ku, Ja Yoon; Park, Young Joo; Lee, Jeong Zoo

    2015-01-01

    Purpose Our objective was to evaluate the use of a holmium laser for transurethral deroofing of a prostatic abscess in patients with severe and multiloculated prostatic abscesses. Materials and Methods From January 2011 to April 2014, eight patients who were diagnosed with prostatic abscesses and who underwent transurethral holmium laser deroofing at Pusan National University Hospital were retrospectively reviewed. Results Multiloculated or multifocal abscess cavities were found on the preoperative computed tomography (CT) scan in all eight patients. All patients who underwent transurethral holmium laser deroofing of a prostatic abscess had successful outcomes, without the need for secondary surgery. Of the eight patients, seven underwent holmium laser enucleation of the prostate (HoLEP) for the removal of residual adenoma. Markedly reduced multiloculated abscess cavities were found in the follow-up CT in all patients. No prostatic abscess recurrence was found. Transient stress urinary incontinence was observed in three patients. The stress urinary incontinence subsided within 3 weeks in two patients and improved with conservative management within 2 months in the remaining patient. Conclusions Transurethral holmium laser deroofing of prostatic abscesses ensures successful drainage of the entire abscess cavity. Because we resolved the predisposing conditions of prostatic abscess, such as bladder outlet obstruction and prostatic calcification, by simultaneously conducting HoLEP, there was no recurrence of the prostatic abscesses after surgery. We recommend our method in patients requiring transurethral drainage. PMID:25685303

  20. Praseodymium Nitrate and Neodymium Complexation with Organophosphorus Reagents in Supercritical Carbon Dioxide Solvent

    SciTech Connect

    Robert V. Fox; R. Duane Ball; Peter de B. Harrington; Harry W. Rollins; John G. Jolley; Chien M. Wai

    2004-11-01

    Complex formation reactions of praseodymium nitrate hexahydrate, and neodymium nitrate hexahydrate salts with tri-n-butyl phosphate (TBP) and several other neutral organophosphorus reagents were investigated in supercritical carbon dioxide. The concentration of the metal complexes in the supercritical fluid (SCF) phase was determined using UV-Vis and luminescence spectroscopies. The stoichiometry of the complexes was determined using the mole-ratio method. Extraction equilibrium constants were calculated from the spectral data using least-squares regression and hard-equilibria models. UV-Vis absorbance data indicate that praseodymium nitrate and neodymium nitrate both form 1:4 lanthanide–tributyl phosphate complexes in supercritical carbon dioxide at 308 K. The conditional extraction coefficients for those two systems were calculated to be log Kex=7.45±0.06 for the praseodymium system and log Kex=7.52±0.03 for the neodymium system. For comparison, neodymium nitrate complexation reactions with tri-n-butyl phosphate and tributyl phosphite (TBPO3) were studied in hexane under ambient conditions. UV-Vis data indicate that a 1:4 neodymium–tributyl phosphate complex is formed in hexane with a conditional extraction coefficient of log Kex=3.4±0.2. Tributyl phosphite forms a 1:8 complex with neodymium in hexane with a conditional extraction coefficient of log Kex=11.0±0.1. Neodymium nitrate was titrated with other organophosphorus reagents, tributyl phosphite and tributyl phosphine oxide (TBPO), in supercritical carbon dioxide to investigate differences between neutral oxygen donor ligands and neutral phosphorus donor ligands. UV-Vis and luminescence data indicate that neodymium nitrate forms a 1:8 complex with tributyl phosphite and a 1:5 complex with tributyl phosphine oxide, compared to a 1:4 complex with tri-n-butyl phosphate. The conditional extraction coefficient for the 1:8 neodymium–tributyl phosphite system was calculated as log Kex=21.4±0.2 from UV

  1. Spectroscopic detection and state preparation of a single praseodymium ion in a crystal.

    PubMed

    Utikal, T; Eichhammer, E; Petersen, L; Renn, A; Götzinger, S; Sandoghdar, V

    2014-01-01

    The narrow optical transitions and long spin coherence times of rare earth ions in crystals make them desirable for a number of applications ranging from solid-state spectroscopy and laser physics to quantum information processing. However, investigations of these features have not been possible at the single-ion level. Here we show that the combination of cryogenic high-resolution laser spectroscopy with optical microscopy allows one to spectrally select individual praseodymium ions in yttrium orthosilicate. Furthermore, this spectral selectivity makes it possible to resolve neighbouring ions with a spatial precision of the order of 10 nm. In addition to elaborating on the essential experimental steps for achieving this long-sought goal, we demonstrate state preparation and read out of the three ground-state hyperfine levels, which are known to have lifetimes of the order of hundred seconds. PMID:24722142

  2. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    DOE PAGESBeta

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-26

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. As a result, this amphoteric doping behavior inmore » the boundary plane is further confirmed by first principles theoretical calculations.« less

  3. Amphoteric Doping of Praseodymium Pr3+ in SrTiO3 Grain Boundaries

    SciTech Connect

    Yang, Hao; Lee, H. S.; Kotula, Paul G.; Sato, Yukio; Ikuhara, Yuichi; Browning, Nigel D.

    2015-03-23

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. This amphoteric doping behavior in the boundary plane is further confirmed by first principles theoretical calculations.

  4. Nonaaqua­praseodymium triiodide–thio­urea (1/2)

    PubMed Central

    Antonenko, Taisia A.; Alikberova, Lyudmila Yu.; Albov, Dmitry V.

    2012-01-01

    The title compound, [Pr(H2O)9]I3·2CS(NH2)2, an adduct of nona­aqua­praseodymium triiodide with two thio­urea mol­ecules, is composed from [Pr(H2O)9]3+ cations (polyhedron: monocapped tetra­gonal anti­prism), noncoordinated thio­urea mol­ecules and iodide anions. The components are evidently connected by hydrogen bonds but in the presence of heavy atoms water H atoms have not been located. The complex cation and one of the two independent iodide anions are located on a twofold axis. PMID:22346801

  5. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    NASA Astrophysics Data System (ADS)

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-01

    Charge compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy. The presence of Pr3+ induces structural variations and changes the statistical prevalence of the GB structures. In contrast to the assumption that Pr3+ substitutes on the Sr site in the bulk, Pr3+ is found to substitute on both Sr and Ti sites inside the GBs, with the highest concentration at the Ti sites. This amphoteric doping behavior in the boundary plane is further confirmed by first principles theoretical calculations.

  6. [A Case of Holmium: YAG Laser Resection of Superficial Bladder Tumor (HoLRBT)].

    PubMed

    Sugita, Yoshiko; Shitara, Toshiya; Hirayama, Takahiro; Fujita, Tetsuo; Yoshida, Kazunari; Kubo, Seiichi; Iwamura, Masatsugu

    2015-10-01

    We present a case of holmium : YAG laser resection of superficial bladder tumor (HoLRBT). A 73-year-old male was referred to our hospital with elevated prostatic specific antigen. Due to difficulty of urination, holmium : YAG laser enucleation of the prostate was performed under the diagnosis of benign prostatic hyperplasia. During the surgery, superficial bladder tumor was incidentally identified, and HoLRBT was performed. After the operation, histopathological examination revealed urothelial carcinoma, G2 > G1, pTa. The patient has been subsequently followed up for 9 months, and there areno evidence of recurrence. Changing the holmium : YAG laser energy setting can potentially be effective and safe to approach a superficial bladder tumor. PMID:26563623

  7. Effect of temperature on the active properties of erbium-doped optical fibres

    NASA Astrophysics Data System (ADS)

    Kotov, L. V.; Ignat'ev, A. D.; Bubnov, M. M.; Likhachev, M. E.

    2016-03-01

    We have studied the effect of heating on the performance of erbium-doped fibre based devices and determined temperaturedependent absorption and emission cross sections of the erbium ion in silica glass. The results demonstrate that heating of fibres in claddingpumped high-power (~100 W) erbium-doped fibre lasers causes no significant decrease in their efficiency. In contrast, superluminescent sources operating in the long-wavelength region (1565 – 1610 nm) are extremely sensitive to temperature changes.

  8. Proximal fiber tip damage during Holmium:YAG and thulium fiber laser ablation of kidney stones

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2016-02-01

    The Thulium fiber laser (TFL) is being studied as an alternative to Holmium:YAG laser for lithotripsy. TFL beam originates within an 18-μm-core thulium doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller fibers than possible during Holmium laser lithotripsy. This study examines whether TFL beam profile also reduces proximal fiber tip damage compared to Holmium laser multimodal beam. TFL beam at wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, 500-μs pulse duration, and pulse rates of 50-500 Hz. For each pulse rate, 500,000 pulses were delivered. Magnified images of proximal fiber surfaces were taken before and after each trial. For comparison, 20 single-use, 270-μm-core fibers were collected after clinical Holmium laser lithotripsy procedures using standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output power was stable, and no proximal fiber damage was observed after delivery of 500,000 pulses at settings up to 35 mJ, 500 Hz, and 17.5 W average power. In contrast, confocal microscopy images of fiber tips after Holmium lithotripsy showed proximal fiber tip degradation in all 20 fibers. The proximal fiber tip of a 105-μm-core fiber transmitted 17.5 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of Holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially reduce costs for the surgical disposables as well.

  9. Single crystal growth and characterization of holmium tartrate trihydrate

    NASA Astrophysics Data System (ADS)

    Want, Basharat; Ahmad, Farooq; Kotru, P. N.

    2007-02-01

    The growth of holmium tartrate trihydrate (HTT) single crystals is achieved in organic (agar-agar) as well as in inorganic (silica) gels by single gel diffusion method. Results of the study on nucleation kinetics of crystals grown in silica gel are described. The crystals exhibit the morphological form of a tetragonal dipyramidal class with {0 0 1} and {1 1 1} as dominant faces. Elemental and thermogravimetric analysis (TGA) supplemented by energy dispersive analysis of X-rays (EDAX) support the suggested chemical formula of the grown crystals to be [Ho (C 4H 4O 6) (C 4H 5O 6)·3H 2O]. Single crystal X-ray diffraction (XRD) studies indicate that the crystals belong to tetragonal system with the cell parameters a=5.97 Å, c=36.09 Å, bearing the space group P4 1. Fourier transform infrared (FT-IR) spectroscopic study indicates the presence of tartrate ligands and suggests that one of the tartrate ions is singly ionized. TGA suggests that the material is thermally stable up to 220 °C.

  10. Magnetic field-dependent spin structures of nanocrystalline holmium

    PubMed Central

    Szary, Philipp; Kaiser, Daniel; Bick, Jens-Peter; Lott, Dieter; Heinemann, André; Dewhurst, Charles; Birringer, Rainer; Michels, Andreas

    2016-01-01

    The results are reported of magnetic field-dependent neutron diffraction experiments on polycrystalline inert-gas condensed holmium with a nanometre crystallite size (D = 33 nm). At T = 50 K, no evidence is found for the existence of helifan(3/2) or helifan(2) structures for the nanocrystalline sample, in contrast with results reported in the literature for the single crystal. Instead, when the applied field H is increased, the helix pattern transforms progressively, most likely into a fan structure. It is the component of H which acts on the basal-plane spins of a given nanocrystallite that drives the disappearance of the helix; for nanocrystalline Ho, this field is about 1.3 T, and it is related to a characteristic kink in the virgin magnetization curve. For a coarse-grained Ho sample, concomitant with the destruction of the helix phase, the emergence of an unusual angular anisotropy (streak pattern) and the appearance of novel spin structures are observed. PMID:27047307

  11. An architecture for quantum computation with magnetically trapped Holmium atoms

    NASA Astrophysics Data System (ADS)

    Saffman, Mark; Hostetter, James; Booth, Donald; Collett, Jeffrey

    2016-05-01

    Outstanding challenges for scalable neutral atom quantum computation include correction of atom loss due to collisions with untrapped background gas, reduction of crosstalk during state preparation and measurement due to scattering of near resonant light, and the need to improve quantum gate fidelity. We present a scalable architecture based on loading single Holmium atoms into an array of Ioffe-Pritchard traps. The traps are formed by grids of superconducting wires giving a trap array with 40 μm period, suitable for entanglement via long range Rydberg gates. The states | F = 5 , M = 5 > and | F = 7 , M = 7 > provide a magic trapping condition at a low field of 3.5 G for long coherence time qubit encoding. The F = 11 level will be used for state preparation and measurement. The availability of different states for encoding, gate operations, and measurement, spectroscopically isolates the different operations and will prevent crosstalk to neighboring qubits. Operation in a cryogenic environment with ultra low pressure will increase atom lifetime and Rydberg gate fidelity by reduction of blackbody induced Rydberg decay. We will present a complete description of the architecture including estimates of achievable performance metrics. Work supported by NSF award PHY-1404357.

  12. Holmium:YAG laser in dentistry: photoconditioning of dentinal surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1994-09-01

    This in vitro study was undertaken to determine energy levels necessary to produce tubule closure and surface smoothing on dentinal surfaces of human teeth and their resultant temperature increases within the pulpal canals with the Holmium:YAG laser. An optimal working spot size and even absorption pattern were produced by defocusing the laser beam and evaluated by images produced on light exposed and developed photographic paper. The surface effects on dentin were examined by scanning electron microscopy. A thermocouple was positioned in the canals of fresh dissected dog jaws and attached to a recorder which produced a graph of the temperature changes. The in vitro research model for intrapulpal temperatures changes was verified by comparing premortem and postmortem temperature readings. The same protocol was used to evaluate temperature changes in fresh human extracted teeth. In vivo histological studies were conducted to evaluate the effects of HO:YAG laser energy on pulpal tissues. The results of these studies indicate the HO:YAG laser at a wavelength of 2.12 microns can be safely and effectively used for photoconditioning of the dentinal surfaces of teeth in clinical conditions.

  13. Clinical development of holmium:YAG laser prostatectomy

    NASA Astrophysics Data System (ADS)

    Kabalin, John N.

    1996-05-01

    Holmium:YAG (Ho:YAG) laser vaporization and resection of the prostate offers advantages in immediate tissue removal compared to the Neodymium:YAG (Nd:YAG) laser. Ongoing development of appropriate operative techniques and Ho:YAG laser delivery systems suitable for endoscopic prostate surgery, including side-firing optical delivery fibers, have facilitated this approach. We performed Ho:YAG laser prostatectomy in 20 human subjects, including 2 men treated immediately prior to radical prostatectomy to assess Ho:YAG laser effects in the prostate. A total of 18 men were treated in an initial clinical trial of Ho:YAG prostatectomy. Estimated excess hyperplastic prostate tissue averaged 24 g (range 5 - 50 g). A mean of 129 kj Ho:YAG laser energy was delivered, combined with a mean of 11 kj Nd:YAG energy to provide supplemental coagulation for hemostasis. We have observed no significant perioperative or late complications. No significant intraoperative changes in hematocrit or serum electrolytes were documented. In addition to providing acute removal of obstructing prostate tissue, Ho:YAG laser resection allowed tissue specimen to be obtained for histologic examination. A total of 16 of 18 patients (90%) underwent successful removal of their urinary catheter and voiding trial within 24 hours following surgery. Immediate improvement in voiding, comparable to classic transurethral electrocautery resection of the prostate (TURP), was reported by all patients. Ho:YAG laser resection of the prostate appears to be a viable surgical technique associated with minimal morbidity and immediate improvement in voiding.

  14. Suppression of optical damage at 532 nm in Holmium doped congruent lithium niobate.

    PubMed

    Barnes, Eftihia; O'Connell, Nathan H; Balli, Nicolas R; Pokhrel, Madhab; Movsesyan, Anush; Kokanyan, Edvard; Sardar, Dhiraj K

    2014-10-20

    Optical damage experiments were carried out in a series of Holmium doped congruent lithium niobate (Ho:cLN) crystals as a function of dopant concentration and laser intensity. The light induced beam distortion was recorded with a camera and a detector under the pseudo-Z-scan configuration. At 532 nm, strong suppression of the optical damage was observed for the 0.94 mol. % doped crystal. Increased resistance to optical damage was also observed at 488 nm. The suppression of the optical damage is predominantly attributed to the reduction of the Nb antisites due to the holmium doping. PMID:25401654

  15. Spectroscopic study and white-light simulation using praseodymium-doped fluorogermanate glass as single phosphor for white LEDs

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Rios, Nathalia P. S. M.; Bueno, Luciano A.

    2012-03-01

    Praseodymium-doped fluorogermanate 60PbGeO3-20PbF2-20CdF2 nano-structured phosphors were synthesized by thermal treatment of precursor glasses. Luminescence features of praseodymium ions incorporated into low-phononenergy PbF2 nanocrystals dispersed in the fluorogermanate glass matrix was evaluated. The luminescence spectra exhibited visible emission signals peaked at 490, 525, 613, 643 nm. White-light emission was observed in praeodymium single-doped phosphor excited using a LED at 460 nm. The dependence of the luminescence emisson intensity upon annealing temperature, and rare-earth concentration was also evaluated. The results indicated the existence of optimum annealing temperature and activator ion concentration to obtain intense emission light with CIE 1931 chromaticity coordinates within the white-light boundary region. Results suggest that the novel nanocomposite glass material herein reported is a promissing phosphor for white-light LED applications

  16. Spectroscopic study and white-light simulation using praseodymium-doped fluorogermanate glass as single phosphor for white LEDs

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Rios, Nathalia P. S. M.; Bueno, Luciano A.

    2012-12-01

    Praseodymium-doped fluorogermanate 60PbGeO3-20PbF2-20CdF2 nano-structured phosphors were synthesized by thermal treatment of precursor glasses. Luminescence features of praseodymium ions incorporated into low-phonon-energy PbF2 nanocrystals dispersed in the fluorogermanate glass matrix was evaluated. The luminescence spectra exhibited visible emission signals peaked at 490, 525, 613, and 643 nm. White-light emission was observed in praeodymium single-doped phosphor excited using a LED at 460 nm. The dependence of the luminescence emission intensity upon annealing temperature, and rare-earth concentration was also evaluated. The results indicated the existence of optimum annealing temperature and activator ion concentration to obtain intense emission light with CIE 1931 chromaticity coordinates within the white-light boundary region. Results suggest that the novel nanocomposite glass material herein reported is a promising phosphor for white-light LED applications.

  17. Adaptive dynamic FBG interrogation utilising erbium-doped fibre

    NASA Astrophysics Data System (ADS)

    John, R. N.; Read, I.; MacPherson, W. N.

    2013-04-01

    A dynamic fibre Bragg grating interrogation scheme is investigated using two-wave mixing in erbium-doped fibre, capable of adapting to quasistatic strain and temperature drifts. An interference pattern set up in the erbium-doped fibre creates, due to the photorefractive effect, a dynamic grating capable of wavelength demodulating the FBG signal. The presence of a dynamic grating was verified and then dynamic strain signals from a fibre stretcher were measured. The adaptive nature of the technique was successfully demonstrated by heating the FBG while it underwent dynamic straining leading to detection unlike an alternative arrayed waveguide grating system which simultaneously failed detection. Two gratings were then wavelength division multiplexed with the signal grating receiving approximately 30dB greater signal showing that there was little cross talk in the system.

  18. Erbium Implantation in Silica Studied by Molecular Dynamics Simulations

    SciTech Connect

    Du, Jincheng; Corrales, Louis R.

    2007-02-01

    Defect formation induced by erbium implantation in silica glass and cristobalite was studied using molecular dynamics simulations employing a partial charge model in combination with the ZBL potential. The results show that the number of displaced atoms generated at the same PKA energy is similar in silica and cristobalite but the number of coordination defects created is much lower in the cristobalite than in silica glass. In both cases, the erbium ion is able to create an optimal coordination environment at the end of the collision cascade. Subsequent thermal annealing causes the relaxation of the silicon oxygen network structure along with a reduction of silicon and oxygen defects. This research is supported by the Divisions of Materials Sciences and Engineering and Chemical Science, Office of Basic Energy Sciences, U.S. Department of Energy. The Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  19. Urbach absorption edge in epitaxial erbium-doped silicon

    SciTech Connect

    Shmagin, V. B. Kudryavtsev, K. E.; Shengurov, D. V.; Krasilnik, Z. F.

    2015-02-07

    We investigate the dependencies of the photocurrent in Si:Er p-n junctions on the energy of the incident photons. The exponential absorption edge (Urbach edge) just below fundamental edge of silicon was observed in the absorption spectra of epitaxial Si:Er layers grown at 400–600 C. It is shown that the introduction of erbium significantly enhances the structural disorder in the silicon crystal which was estimated from the slope of the Urbach edge. We discuss the possible nature of the structural disorder in Si:Er and a new mechanism of erbium excitation, which does not require the presence of deep levels in the band gap of silicon.

  20. Transient photoacoustic effects induced in liquids by pulsed erbium lasers

    NASA Astrophysics Data System (ADS)

    Frenz, Martin; Pratisto, Hans; Ith, Michael; Asshauer, Thomas; Rink, Klaus; Delacretaz, Guy P.; Romano, Valerio; Salathe, Rene-Paul; Weber, Heinz P.

    1994-08-01

    The intense interest in the investigation of erbium laser radiation in medicine is due to the fact that radiation at 3 micrometers is very strongly absorbed by water, which is present in all biological tissue. As a consequence of this high absorption the interaction of pulsed radiation is characterized by an explosive process with a low ablation threshold and a thin coagulation zone along the laser incisions. Erbium lasers, therefore, have a wide field of potential medical applications which become even more attractive with the availability of reliable delivery systems. An interesting situation arises in orthopaedics and angioplasty, where a precise cutting instrument is needed in a liquid environment. For this reason, we experimentally investigated the interaction mechanism of fiber transmitted, pulsed, free-running and Q- switched Erbium:YSGG ((lambda) equals 2.79 micrometers ) and Erbium:YAG ((lambda) equals 2.94 micrometers ) laser radiation with liquid water. The dynamics of the bubble formation and the propagation of shockwaves in water was studied and visualized by flash photography. Acoustic transients of a few hundreds of bars accompanying the ablation process were measured with a needle hydrophone. A clear correlation between the spikes of the laser pulse and those of the pressure signal was observed. Additionally, strong pressure transients were measured after the end of the laser pulse, which could be associated with the collapse of the vapor bubble and further collapses after multiple rebounds. The influence of pulse energy, fiber size and pulse duration on the formation and the amplitude of the pressure waves is demonstrated.

  1. Laser isotope separation of erbium and other isotopes

    DOEpatents

    Haynam, C.A.; Worden, E.F.

    1995-08-22

    Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of {sup 167}Er. The hyperfine structure of {sup 167}Er was used to find two three-step photoionization pathways having a common upper energy level. 3 figs.

  2. Laser isotope separation of erbium and other isotopes

    DOEpatents

    Haynam, Christopher A.; Worden, Earl F.

    1995-01-01

    Laser isotope separation is accomplished using at least two photoionization pathways of an isotope simultaneously, where each pathway comprises two or more transition steps. This separation method has been applied to the selective photoionization of erbium isotopes, particularly for the enrichment of .sup.167 Er. The hyperfine structure of .sup.167 Er was used to find two three-step photoionization pathways having a common upper energy level.

  3. Erbium-doped fiber lasers as deep-sea hydrophones

    NASA Astrophysics Data System (ADS)

    Bagnoli, P. E.; Beverini, N.; Bouhadef, B.; Castorina, E.; Falchini, E.; Falciai, R.; Flaminio, V.; Maccioni, E.; Morganti, M.; Sorrentino, F.; Stefani, F.; Trono, C.

    2006-11-01

    The present work describes the development of a hydrophone prototype for deep-sea acoustic detection. The base-sensitive element is a single-mode erbium-doped fiber laser. The high sensitivity of these sensors makes them particularly suitable for a wide range of deep-sea acoustic applications, including geological and marine mammals surveys and above all as acoustic detectors in under-water telescopes for high-energy neutrinos.

  4. Optical emission from erbium-doped silica nanowires

    NASA Astrophysics Data System (ADS)

    Elliman, R. G.; Wilkinson, A. R.; Kim, T.-H.; Sekhar, P. K.; Bhansali, S.

    2008-05-01

    Infrared optical emission from erbium-doped silica nanowires is shown to have property characteristic of the material nanostructure and to provide the basis for the fabrication of integrated photonic devices and biosensors. Silica nanowires of approximately 150 nm diameter were grown on a silicon wafer by metal-induced growth using a thin (20 nm) sputter-deposited palladium layer as a catalyst. The resulting wires were then ion implanted with 110 keV ErO- ions and annealed at 900 °C to optically activate the erbium. These wires exhibited photoluminescence emission at 1.54 μm, characteristic of the I415/2-I413/2 transition in erbium; however, comparison to similarly implanted fused silica layers revealed stronger thermal quenching and longer luminescence lifetimes in the nanowire samples. The former is attributed to an increase in defect-induced quenching partly due to the large surface-volume ratio of the nanowires, while the latter is attributed to a reduction in the optical density of states associated with the nanostructure morphology. Details of this behavior are discussed together with the implications for potential device applications.

  5. Pressure-dependent resistivity and magnetoresistivity of erbium

    NASA Astrophysics Data System (ADS)

    Ellerby, Mark; McEwen, Keith A.; Bauer, Ernst; Hauser, Robert; Jensen, Jens

    2000-03-01

    A comprehensive resistance study of erbium subjected to a hydrostatic pressure is presented. From the experimental results we derive a p-T phase diagram for the magnetic phases in erbium. In the zero-temperature limit, the conical structure is predicted to transform into the cycloidal one at a pressure of about 1.3 kbar. Experimentally, the transition is found to occur between 1 and 3 kbar at 4.5 K. The experimental results are analyzed in terms of a variational calculation of the resistivity using the model developed for erbium from previous experiments. The theory of Elliott and Wedgwood is utilized in the account of the superzone effects. The analysis indicates that the a-axis resistivity is slightly affected by the superzones. In the c-axis case the superzone effects do not simply scale with the magnetization, but also reflect the 20% change of the ordering wave vector. This occurs between TN and TC at ambient pressure, and at 4.5 K when the pressure is increased from 1 to 3 kbar. It is tentatively proposed that the tilted cycloidal structure exists in Er, just above TC at ambient pressure and in the interval between 1.3 and 9 kbar at zero temperature.

  6. Magnetic phase diagrams of hexagonal rare earth manganites, R-manganese oxide (R = holmium, erbium, thullium, ytterbium) and other multiferroics: Gadolinium triiron tetraborate, nickel orthovanadate, and holmium manganese pentoxide

    NASA Astrophysics Data System (ADS)

    Yen, Fei

    Materials exhibiting ferroelectricity or ferroelasticity and some type of magnetic order are considered to be multiferroic. The understanding of the driving mechanisms behind some of the phase transitions and the phases for which multiferroic behavior occurs is essential in order to devise applicable devices. This work studies the coexistence of various orders and how they couple with each other. The magnetic phase diagrams of hexagonal RMnO 3 (R=Ho, Er, Tm and Yb) compounds are studied and compared to each other. In the case of HoMnO3, a rich magnetic phase diagram develops at lower temperatures. For GdFe3(BO3)4, its spin rotation phase transition is found to split under the application of magnetic fields. The environment for which ferroelectricity arises is studied. For Ni3V2O8, a tri-critical point is found in its pressure-temperature phase diagram and found that with increasing pressure its magneto-electric coupling diminishes. Isotope exchange was performed on HoMn2O5 to determine its effect on any of its transition temperatures or order parameter coupling. Keywords. hexagonal RMnO3, GdFe3(BO 3)4, Ni3V2O8, HoMn 2O5, multiferroic, ferroelectricity, stacked triangular anti ferromagnet, dielectric constant, heat capacity, magneto-dielectric effect, magnetic Clausius-Clapeyron, Kagome lattice, ferroelectric polarization, pyroelectric current, isotope exchange, tri-critical point, first order phase transitions, incommensurate-commensurate phase transitions, magnetic anisotropy.

  7. Measurement of cross sections for charge pickup by relativistic holmium ions on heavy targets

    SciTech Connect

    Westphal, A.J.; Guiru, J.; Price, P.B. Nuclear Science Division, Lawrence Berkeley Laboratory, Berkeley, California )

    1991-10-01

    We have measured the cross section for nuclear charge pickup by relativistic holmium on several targets of larger atomic number than have been studied previously. We find that although measurements made with most of the targets are consistent with a peripheral geometric scaling, one target, silver, shows an anomalously high cross section.

  8. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers

    NASA Astrophysics Data System (ADS)

    Blackmon, Richard L.; Case, Jason R.; Trammell, Susan R.; Irby, Pierce B.; Fried, Nathaniel M.

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ˜2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract.

  9. Holmium laser for treatment of benign prostatic hyperplasia: old wine in a new bottle?

    NASA Astrophysics Data System (ADS)

    Nelius, Thomas; de Riese, Werner T. W.

    2003-06-01

    Urinary tract symptoms related to benign prostatic hyperplasia affect 70% of men older than 70 years. Complications are common problems and a significant cause of morbidity in this population, placing a considerable burden on health services. In the early 1990s laser treatment of benign prostatic hyperplasia became widely used after the introduction of the side-firing neodym: YAG laser. However, because of technical limitations and inferior results compared to classical transurethral resection of the prostate many Urologists became desinterested in this device. With the introduction of the holmium: YAG laser a new laser generation became available for use in Urology. Beside several other applications the holmium: YAG laser can be used for incision, ablation, resection, and more recently enucleation of the prostate. In this paper we reviewed the current literature regarding the holmium: YAG laser resection and enucleation of the prostate compared to transurethral resection of the prostate and open prostatectomy. The holmium: YAG laser technique is an effective and durable surgical alternative to standard transurethral resection of the prostate. Interestingly, enucleation of the prostate with this device seems to be a safe and effective procedure for large prostatic adenomas, it may become an attractive alternative to open prostatectomy.

  10. Preparation and complex characterization of silica holmium sol-gel monoliths.

    PubMed

    Cacaina, D; Areva, S; Laaksonen, H; Simon, S; Ylänen, H

    2011-01-01

    Amorphous, sol-gel derived SiO(2) are known to biocompatible and bioresorbable materials. Biodegradable and inert materials containing radioactive isotopes have potential application as delivery vehicles of the beta radiation to the cancer tumors inside the body. Incorporation of holmium in the sol-gel derived SiO(2) could lead to the formation of a biodegradable material which could be used as carrier biomaterial for the radiation of radioactive holmium to the various cancer sites. The homogeneity of the prepared sol-gel silica holmium monoliths was investigated by Back Scattered Electron Imaging of Scanning Electron Microscope equipped with Energy Dispersive X-ray Analysis, X-ray Induced Photoelectron Spectroscopy and Nuclear Magnetic Resonance Spectroscopy. The biodegradation of the monoliths was investigated in Simulated Body Fluid and TRIS (Trizma pre-set Crystals) solution. The results show that by suitable tailoring of the sol-gel processing parameters holmium can be homogeneously incorporated in the silica matrix with a controlled biodegradation rate. PMID:21132520

  11. Fiber-optic manipulation of urinary stone phantoms using holmium:YAG and thulium fiber lasers.

    PubMed

    Blackmon, Richard L; Case, Jason R; Trammell, Susan R; Irby, Pierce B; Fried, Nathaniel M

    2013-02-01

    Fiber-optic attraction of urinary stones during laser lithotripsy may be exploited to manipulate stone fragments inside the urinary tract without mechanical grasping tools, saving the urologist time and space in the ureteroscope working channel. We compare thulium fiber laser (TFL) high pulse rate/low pulse energy operation to conventional holmium:YAG low pulse rate/high pulse energy operation for fiber-optic suctioning of plaster-of-paris (PoP) stone phantoms. A TFL (wavelength of 1908 nm, pulse energy of 35 mJ, pulse duration of 500 μs, and pulse rate of 10 to 350 Hz) and a holmium laser (wavelength of 2120 nm, pulse energy of 35 to 360 mJ, pulse duration of 300 μs, and pulse rate of 20 Hz) were tested using 270-μm-core optical fibers. A peak drag speed of ~2.5 mm/s was measured for both TFL (35 mJ and 150 to 250 Hz) and holmium laser (210 mJ and 20 Hz). Particle image velocimetry and thermal imaging were used to track water flow for all parameters. Fiber-optic suctioning of urinary stone phantoms is feasible. TFL operation at high pulse rates/low pulse energies is preferable to holmium operation at low pulse rates/high pulse energies for rapid and smooth stone pulling. With further development, this novel technique may be useful for manipulating stone fragments in the urinary tract. PMID:23377013

  12. Histological evaluation of coagulation foci produced in the human lens with a holmium laser

    NASA Astrophysics Data System (ADS)

    Kecik, Dariusz; Kecik, Tadeusz; Pratnicki, Antoni; Kasprzak, Jan; Kecik, Mariusz

    1997-10-01

    We present the results of histological evaluation of human lenses treated with the holmium laser. The lenses, extracted at the time of extracapsular surgery for cataract, were placed in containers filled with Ringer's solution. After treatment with laser-emitted radiation they were histologically evaluated. The formation of crater-like defects was found in the material studied.

  13. Femtosecond mode-locked holmium fiber laser pumped by semiconductor disk laser.

    PubMed

    Chamorovskiy, A; Marakulin, A V; Ranta, S; Tavast, M; Rautiainen, J; Leinonen, T; Kurkov, A S; Okhotnikov, O G

    2012-05-01

    We report on a 2085 nm holmium-doped silica fiber laser passively mode-locked by semiconductor saturable absorber mirror and carbon nanotube absorber. The laser, pumped by a 1.16 μm semiconductor disk laser, produces 890 femtosecond pulses with the average power of 46 mW and the repetition rate of 15.7 MHz. PMID:22555700

  14. Chiral holmium complex-catalyzed Diels-Alder reaction of silyloxyvinylindoles: stereoselective synthesis of hydrocarbazoles.

    PubMed

    Harada, Shinji; Morikawa, Takahiro; Nishida, Atsushi

    2013-10-18

    The catalytic and asymmetric cycloaddition between 3-[1-(silyloxy)vinyl]indoles and electron-deficient olefins gave substituted hydrocarbazoles in up to 99% yield and 94% ee. This reaction was catalyzed by a novel chiral holmium(III) complex. Alkylation of the cycloadduct gave a tricyclic compound with four continuous chiral centers, one of which was a quaternary carbon. PMID:24079531

  15. Laser-assisted hair transplantation: histologic comparison between holmium:YAG and CO2 lasers

    NASA Astrophysics Data System (ADS)

    Chu, Eugene A.; Rabinov, C. Rose; Wong, Brian J.; Krugman, Mark E.

    1999-06-01

    The histological effects of flash-scanned CO2 (λ=10.6μm) and pulsed Holmium:YAG (Ho:YAG, λ=2.12μm) lasers were evaluated in human scalp following the creation of hair transplant recipient channels. Ho:YAG laser irradiation created larger zones of thermal injury adjacent to the laser channels than irradiation with the CO2 laser device. When the two lasers created recipient sites of nearly equal depth, the Holmium:YAG laser caused a larger region of lateral thermal damage (589.30μm) than the CO2 laser (118.07μm). In addition, Holmium:YAG irradiated specimens exhibited fractures or discontinuities beyond the region of clear thermal injury. This shearing effect is consistent with the photoacoustic mechanism of ablation associated with pulsed mid-IR laser irradiation. In contrast, channels created with the CO2 exhibited minimal epithelial disruption and significantly less lateral thermal damage. While the Holmium:YAG laser is a useful tool for ablation soft tissue with minimal char in select applications (sinus surgery, arthroscopic surgery), this study suggests that the use of the CO2 laser for the creation of transplantation recipient channels result in significantly less lateral thermal injury for the laser parameters employed.

  16. High-performace cladding-pumped erbium-doped fibre laser and amplifier

    SciTech Connect

    Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Lipatov, D S; Vechkanov, N N; Guryanov, Aleksei N

    2012-05-31

    We report cladding-pumped erbium-doped fibre laser and amplifier configurations. Through fibre design optimisation, we have achieved a record-high laser slope efficiency, 40 % with respect to absorbed pump power ({lambda} = 976 nm), and an output power of 7.5 W. The erbium-doped fibre amplifier efficiency reaches 32 %.

  17. Evaluating United States and world consumption of neodymium, dysprosium, terbium, and praseodymium in final products

    NASA Astrophysics Data System (ADS)

    Hart, Matthew

    This paper develops scenarios of future rare-earth-magnet metal (neodymium, dysprosium, terbium, and praseodymium) consumption in the permanent magnets used in wind turbines and hybrid electric vehicles. The scenarios start with naive base-case scenarios for growth in wind-turbine and hybrid-electric-vehicle sales over the period 2011 to 2020, using historical data for each good. These naive scenarios assume that future growth follows time trends in historical data and does not depend on any exogenous variable. Specifically, growth of each technological market follows historical time trends, and the amount of rare earths used per unit of technology remains fixed. The chosen reference year is 2010. Implied consumptions of the rare earth magnet metals are calculated from these scenarios. Assumptions are made for the material composition of permanent magnets, the market share of permanent-magnet wind turbines and vehicles, and magnet weight per unit of technology. Different scenarios estimate how changes in factors like the material composition of magnets, growth of the economy, and the price of a substitute could affect future consumption. Each scenario presents a different method for reducing rare earth consumption and could be interpreted as potential policy choices. In 2010, the consumption (metric tons, rare-earth-oxide equivalent) of each rare-earth-magnet metal was as follows. Total neodymium consumption in the world for both technologies was 995 tons; dysprosium consumption was 133 tons; terbium consumption was 50 tons; praseodymium consumption was zero tons. The base scenario for wind turbines shows there could be strong, exponential growth in the global wind turbine market. New U.S. sales of hybrid vehicles would decline (in line with the current economic recession) while non-U.S. sales increase through 2020. There would be an overall increase in the total amount of magnetic rare earths consumed in the world. Total consumption of each rare earth in the short

  18. Performance analysis of a concatenated erbium-doped fiber amplifier supporting four mode groups

    NASA Astrophysics Data System (ADS)

    Qin, Zujun; Fan, Di; Zhang, Wentao; Xiong, Xianming

    2016-05-01

    An erbium-doped fiber amplifier (EDFA) supporting four mode groups has been theoretically designed by concatenating two sections of erbium-doped fibers (EDFs). Each EDF has a simple erbium doping profile for the purpose of reducing its fabrication complexity. We propose a modified genetic algorithm (GA) to provide detailed investigations on the concatenated amplifier. Both the optimal fiber length and erbium doping radius in each EDF have been found to minimize the gain difference between signal modes. Results show that the parameters of the central-doped EDF have a greater impact on the amplifier performance compared to those of the annular-doped one. We then investigate the influence of the small deviations of the erbium fiber length, doping radius and doping concentration of each EDF from their optimal values upon the amplifier performance, and discuss their design tolerances in obtaining a desirable amplification characteristics.

  19. Optical constants determination of samarium, holmium, and erbium in the 1.5-850 eV spectral range using a transmittance method

    SciTech Connect

    Kjornrattanawanich, Benjawan; Windt, David L.; Seely, John F.

    2010-11-01

    The optical constants {beta} and {delta} of the complex refractive index n{approx}=1-{delta}+i{beta} of Sm, Ho, and Er were obtained in the 1.5-850eV energy range using a transmittance method. Thin films of Sm, Ho, and Er were deposited by magnetron sputtering, and transmittance was measured using synchrotron radiation under a high vacuum condition. All films were directly coated on Si photodiodes, which were used as coating substrates, as well as photon detectors. Si was used as capping layer while a thin W layer was used as barrier against interface diffusion between Si and the highly reactive rare earth elements. The constants {beta} were extracted from transmittance results, and the constants {delta} were calculated based on measured {beta} values using the Kramers-Kronig formalism. Small deficiencies determined from the present data using the partial sum rules were partly attributed to the sputtered film densities that could be slightly lower than the bulk values.

  20. Optical Constants Determination of Samarium Holmium and Erbium in the 1.5-850 eV Spectral Range using a Transmittance Method

    SciTech Connect

    B Kjornrattanawanich; D Windt; J Seely

    2011-12-31

    The optical constants {beta} and {sigma} of the complex refractive index {tilde n} = 1 - {delta} + i{beta} of Sm, Ho, and Er were obtained in the 1.5-850 eV energy range using a transmittance method. Thin films of Sm, Ho, and Dr were deposited by magnetron sputtering, and transmittance was measured using synchrotron radiation using a high vacuum condition. All films were directly coated on Si photodiodes, which were used as coating substrates, as well as photon detectors. Si was used as capping layer while a thin W layer was used as barrier against interface diffusion between Si and the highly reactive rare earth elements. The constants {beta} were extracted from transmittance results, and the constants {sigma} were calculated based on measured {beta} values using the Kramers-Kronig formalism. Small deficiencies determined from the present data using the partial sum rules were partially attributed to the sputtered film densities that could be slightly lower than the bulk values.

  1. Comparative analysis of the optical spectra of the holmium atom excited by electron impact and ionic bombardment

    SciTech Connect

    Vasileva, E.K.; Morozov, S.N.; Ryskin, B.V.

    1988-02-01

    A comparative analysis of the optical spectra of holmium excited by electron impact and ionic bombardment is given. It is shown that under ionic bombardment, the probability of excitation of screened transitions is significantly higher than under electron impact.

  2. Holmium:YAG laser coronary angioplasty: quantitative angiography and clinical results in a large experience of a single medical center

    NASA Astrophysics Data System (ADS)

    Topaz, On; Luxenberg, Michael; Schumacher, Audrey

    1994-07-01

    Clinical experience with the mid IR holmium:YAG laser in a single medical center (St. Paul Ramsey Medical Center, University of Minnesota Medical School, St. Paul, MN) includes 112 patients who underwent holmium laser coronary angioplasty. Utilizing a unique lasing technique; `pulse and retreat,' we applied this laser to thrombotic and nonthrombotic lesions in patients presenting with unstable angina, stable angina, and acute myocardial infarction. A very high clinical success and very low complication rates were achieved. Holmium:YAG laser is effective and safe therapy for patients with symptomatic coronary artery disease. Unlike excimer lasers, the clinical success, efficacy and safety of holmium laser angioplasty is not compromised when thrombus is present.

  3. Valence of praseodymium in superconducting Pr(O,F)BiS2 single crystals

    NASA Astrophysics Data System (ADS)

    Ishii, Satoshi; Hongu, Yasuaki; Miura, Akira; Nagao, Masanori

    2016-06-01

    The praseodymium (Pr) valence in superconducting PrO1‑ x F x BiS2 (x = 0.13,0.23) single crystals was evaluated by X-ray photoelectron spectroscopy. The Pr 3d core level is split into 3d3/2 and 3d5/2 levels. Both PrO1‑ x F x BiS2 and Pr2S3, which contain only Pr3+, showed 3d spectra at a lower binding energy than Pr6O11, which contains both Pr3+ and Pr4+. Neither PrO1‑ x F x BiS2 nor Pr2S3 showed the characteristic satellites of Pr4+ in 3d5/2 spectra. The valence fluctuation between the Pr3+ and Pr4+ states was not confirmed, suggesting that Pr3+ is dominant in PrO1‑ x F x BiS2 (x = 0.13,0.23) single crystals.

  4. RM1 Semiempirical Quantum Chemistry: Parameters for Trivalent Lanthanum, Cerium and Praseodymium.

    PubMed

    Dutra, José Diogo L; Filho, Manoel A M; Rocha, Gerd B; Simas, Alfredo M; Freire, Ricardo O

    2015-01-01

    The RM1 model for the lanthanides is parameterized for complexes of the trications of lanthanum, cerium, and praseodymium. The semiempirical quantum chemical model core stands for the [Xe]4fn electronic configuration, with n =0,1,2 for La(III), Ce(III), and Pr(III), respectively. In addition, the valence shell is described by three electrons in a set of 5d, 6s, and 6p orbitals. Results indicate that the present model is more accurate than the previous sparkle models, although these are still very good methods provided the ligands only possess oxygen or nitrogen atoms directly coordinated to the lanthanide ion. For all other different types of coordination, the present RM1 model for the lanthanides is much superior and must definitely be used. Overall, the accuracy of the model is of the order of 0.07Å for La(III) and Pr(III), and 0.08Å for Ce(III) for lanthanide-ligand atom distances which lie mostly around the 2.3Å to 2.6Å interval, implying an error around 3% only. PMID:26132289

  5. RM1 Semiempirical Quantum Chemistry: Parameters for Trivalent Lanthanum, Cerium and Praseodymium

    PubMed Central

    Dutra, José Diogo L.; Filho, Manoel A. M.; Rocha, Gerd B.; Simas, Alfredo M.; Freire, Ricardo O.

    2015-01-01

    The RM1 model for the lanthanides is parameterized for complexes of the trications of lanthanum, cerium, and praseodymium. The semiempirical quantum chemical model core stands for the [Xe]4fn electronic configuration, with n =0,1,2 for La(III), Ce(III), and Pr(III), respectively. In addition, the valence shell is described by three electrons in a set of 5d, 6s, and 6p orbitals. Results indicate that the present model is more accurate than the previous sparkle models, although these are still very good methods provided the ligands only possess oxygen or nitrogen atoms directly coordinated to the lanthanide ion. For all other different types of coordination, the present RM1 model for the lanthanides is much superior and must definitely be used. Overall, the accuracy of the model is of the order of 0.07Å for La(III) and Pr(III), and 0.08Å for Ce(III) for lanthanide-ligand atom distances which lie mostly around the 2.3Å to 2.6Å interval, implying an error around 3% only. PMID:26132289

  6. Lanthanum(III) and praseodymium(III) complexes with isatin thiosemicarbazones

    NASA Astrophysics Data System (ADS)

    Rai, Anita; Sengupta, Soumitra K.; Pandey, Om P.

    2005-09-01

    Ten new lanthanum(III) and praseodymium(III) complexes of the general formula Na[La(L) 2H 2O] (Ln = La(III) or Pr(III); LH 2 = thiosemicarbazones) derived from the condensation of isatin with 4-phenyl thiosemicarbazide, 4-(4-chlorophenyl) thiosemicarbazide, 4-(2-nitrophenyl) thiosemicarbazide, 4-(2-bromophenyl) thiosemicarbazide and 4-(2-methylphenyl) thiosemicarbazide, have been synthesized in methanol in presence of sodium hydroxide. The XRD spectra of the complexes were monitored to verify complex formation. The complexes have also been characterized by elemental analysis, molar conductance, electronic absorption and fluorescence, infrared, far infrared, 1H and 13C NMR spectral studies. Thermal studies of these complexes have been carried out in the temperature range 25-800 °C using TG, DTG and DTA techniques. All these complexes decompose gradually with the formation of Ln 2O 3 as the end product. The Judd-ofelt intensity parameter, oscillator strength, transition probability, stimulated emission cross section for different transitions of Pr 3+ for 4-phenyl thiosemicarbazones have been calculated.

  7. Structural studies of lithium boro tellurite glasses doped with praseodymium and samarium oxides

    SciTech Connect

    Damas, Pedro; Coelho, João; Hungerford, Graham; Hussain, N. Sooraj

    2012-11-15

    Graphical abstract: [TeO{sub 4}] trigonal bipyramid structural unit, which is formed by two unequivalent pair of oxygen atoms: two equatorial oxygens (O{sub eq}) and two axial oxygens (O{sub ax}). Highlights: ► Pr{sup 3+} and Sm{sup 3+} doped LBT glasses have been prepared and characterized. ► LBT glasses present normal surfaces without metallic clusters. ► Raman spectra revealed the network modifying behaviour of dopant ions. -- Abstract: This paper reports the preparation and structural studies of praseodymium and samarium (0.5, 2 and 4 mol%) oxide doped lithium boro tellurite glasses. These materials were prepared by the quenching technique in a ceramic crucible at 950 °C. Structural characterization was performed by Raman spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-ray spectroscopy techniques. Results from Raman analysis are in good agreement with those reported in the literature, revealing a normal glass structure for the host material. Understanding on how the glasses internal structure changed when the doping concentration increases was also assessed.

  8. Electronic-structure calculations of praseodymium metal by means of modified density-functional theory

    SciTech Connect

    Svane, A.; Trygg, J.; Johansson, B.; Eriksson, O. |

    1997-09-01

    Electronic-structure calculations of elemental praseodymium are presented. Several approximations are used to describe the Pr f electrons. It is found that the low-pressure, trivalent phase is well described using either the self-interaction corrected (SIC) local-spin-density (LSD) approximation or the generalized-gradient approximation (GGA) with spin and orbital polarization (OP). In the SIC-LSD approach the Pr f electrons are treated explicitly as localized with a localization energy given by the self-interaction of the f orbital. In the GGA+OP scheme the f-electron localization is described by the onset of spin and orbital polarization, the energetics of which is described by spin-moment formation energy and a term proportional to the total orbital moment, L{sub z}{sup 2}. The high-pressure phase is well described with the f electrons treated as band electrons, in either the LSD or the GGA approximations, of which the latter describes more accurately the experimental equation of state. The calculated pressure of the transition from localized to delocalized behavior is 280 kbar in the SIC-LSD approximation and 156 kbar in the GGA+OP approach, both comparing favorably with the experimentally observed transition pressure of 210 kbar. {copyright} {ital 1997} {ital The American Physical Society}

  9. Pyramidal structural defects in erbium silicide thin films

    NASA Astrophysics Data System (ADS)

    Tan, Eu Jin; Bouville, Mathieu; Chi, Dong Zhi; Pey, Kin Leong; Lee, Pooi See; Srolovitz, David J.; Tung, Chih Hang

    2006-01-01

    Pyramidal structural defects, 5-8μm wide, have been discovered in thin films of epitaxial ErSi2-x formed by annealing thin Er films on Si(001) substrates at temperatures of 500-800°C. The formation of these defects is not due to oxidation. We propose that they form as a result of the separation of the silicide film from the substrate and its buckling in order to relieve the compressive, biaxial epitaxial stresses. Silicon can then diffuse through the silicide or along the interface to fully or partially fill the void between the buckled erbium disilicide film and the substrate.

  10. Erbium-doped fiber amplifier elements for structural analysis sensors

    NASA Technical Reports Server (NTRS)

    Hanna-Hawver, P.; Kamdar, K. D.; Mehta, S.; Nagarajan, S.; Nasta, M. H.; Claus, R. O.

    1992-01-01

    The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed.

  11. Erbium-doped fiber amplifier elements for structural analysis sensors

    NASA Astrophysics Data System (ADS)

    Hanna-Hawver, P.; Kamdar, K. D.; Mehta, S.; Nagarajan, S.; Nasta, M. H.; Claus, R. O.

    1992-06-01

    The use of erbium-doped fiber amplifiers (EDFA's) in optical fiber sensor systems for structural analysis is described. EDFA's were developed for primary applications as periodic regenerator amplifiers in long-distance fiber-based communication systems. Their in-line amplification performance also makes them attractive for optical fiber sensor systems which require long effective lengths or the synthesis of special length-dependent signal processing functions. Sensor geometries incorporating EDFA's in recirculating and multiple loop sensors are discussed. Noise and polarization birefringence are also considered, and the experimental development of system components is discussed.

  12. Erbium Doped Fiber Sensor for Ammonia Detection into Water

    NASA Astrophysics Data System (ADS)

    Pérez-Sánchez, G. G.; Pinzón-Escobar, E. F.; Sandoval-Romero, G. E.; Álvarez Chávez, J. A.

    2015-01-01

    The water pollution is a health problem around the world. One of the most common pollutants in water is the Ammonia. Some sensors have been developed for Ammoniac detection even though most of them are not in real time and could be expensive. In this work an Erbium-doped fibre-sensor for Ammonia detection with a mechanical long period fibre grating and a taper in cascade for improving the sensitivity; the detection bandwidth is in the 1550 nm region from 1460 nm to 1640 nm. Output optical spectrum for Ammonia concentrations from 1ml to 5 ml is shown

  13. Kinetic lattice Monte Carlo model for oxygen vacancy diffusion in praseodymium doped ceria: Applications to materials design

    SciTech Connect

    Dholabhai, Pratik P.; Anwar, Shahriar; Adams, James B.; Crozier, Peter; Sharma, Renu

    2011-04-15

    Kinetic lattice Monte Carlo (KLMC) model is developed for investigating oxygen vacancy diffusion in praseodymium-doped ceria. The current approach uses a database of activation energies for oxygen vacancy migration, calculated using first-principles, for various migration pathways in praseodymium-doped ceria. Since the first-principles calculations revealed significant vacancy-vacancy repulsion, we investigate the importance of that effect by conducting simulations with and without a repulsive interaction. Initially, as dopant concentrations increase, vacancy concentration and thus conductivity increases. However, at higher concentrations, vacancies interfere and repel one another, and dopants trap vacancies, creating a 'traffic jam' that decreases conductivity, which is consistent with the experimental findings. The modeled effective activation energy for vacancy migration slightly increased with increasing dopant concentration in qualitative agreement with the experiment. The current methodology comprising a blend of first-principle calculations and KLMC model provides a very powerful fundamental tool for predicting the optimal dopant concentration in ceria related materials. -- graphical abstract: Ionic conductivity in praseodymium doped ceria as a function of dopant concentration calculated using the kinetic lattice Monte Carlo vacancy-repelling model, which predicts the optimal composition for achieving maximum conductivity. Display Omitted Research highlights: {yields} KLMC method calculates the accurate time-dependent diffusion of oxygen vacancies. {yields} KLMC-VR model predicts a dopant concentration of {approx}15-20% to be optimal in PDC. {yields} At higher dopant concentration, vacancies interfere and repel one another, and dopants trap vacancies. {yields} Activation energy for vacancy migration increases as a function of dopant content

  14. Photoluminescence of Erbium-Doped Potassium Tantalate Niobate Polycrystalline

    NASA Astrophysics Data System (ADS)

    Wen, Cheng‑Hung; Chu, Sheng‑Yuan; Shin, Yan‑Yu; Wen, Cheng‑Kuo

    2006-07-01

    In this study, we investigated the luminescence properties of erbium-doped potassium tantalite niobate (KTaxNb1-xO3 or KTN) ceramics, which were prepared by the conventional solid-state reaction synthesis method. In this work, we studied the relationships of the crystal structure, and Raman and photoluminescence (PL) spectra with the tantalum concentration, respectively. The experiments showed that the tantalum dopants modified the intensity of the green, red and near-infrared emission bands. The experiments also showed a blue shift for the 2 mol % erbium doped KTN samples with different tantalum compositions. Doping Ta not only led to the change in PL intensity but also in spectral shapes. The PL spectra showed the splitting peaks for the samples with low Ta compositions. Then these peaks combined and broadened as Ta concentration increase. When Ta was substituted for Nb completely, the luminescence intensity of the green emission band had an increase of approximately about one order of magnitude, which was because of the absence of the first-order phonon relaxation in the high-Ta-concentration samples.

  15. Harmonically mode-locked erbium-doped waveguide laser

    NASA Astrophysics Data System (ADS)

    Fanto, Michael L.; Malowicki, John E.; Bussjager, Rebecca J.; Johns, Steven T.; Vettese, Elizabeth K.; Hayduk, Michael J.

    2004-08-01

    The generation of ultrastable picosecond pulses in the 1550 nm range is required for numerous applications that include photonic analog-to-digital converter systems and high-bit rate optical communication systems. Mode-locked erbium-doped fiber ring lasers (EDFLs) are typically used to generate pulses at this wavelength. In addition to timing stability and output power, the physical size of the laser cavity is of primary importance to the Air Force. The length of the erbium (Er)-doped fiber used as the gain medium may be on the order of meters or even tens of meters which adds complexity to packaging. However, with the recent advancements in the production of multi-component glasses, higher doping concentrations can be achieved as compared to silicate glasses. Even more recent is the introduction of Er-doped multi-component glass waveguides, thus allowing the overall footprint of the gain medium to be reduced. We have constructed a novel harmonically mode-locked fiber ring laser using the Er-doped multi-component glass waveguide as the gain medium. The performance characteristics of this Er-doped waveguide laser (EDWL) including pulse width, spectral width, harmonic suppression, optical output power, laser stability and single sideband residual phase noise will be discussed in this paper.

  16. Evidence of two erbium sites in standard aluminosilicate glass for EDFA.

    PubMed

    Peretti, R; Jurdyc, A M; Jacquier, B; Burov, E; Pastouret, A

    2010-09-27

    Site distributions of Er(3+)-doped aluminosilicate preforms of standard EDFA were studied by the low temperature Resonant Fluorescence Line Narrowing (RFLN) spectroscopy. Two erbium concentration samples with the same glass base were investigated. At very low erbium concentration, two classes of sites were identified, related to the number of AlO(6) octahedral linked by two oxygen edge-sharing to Er(3+) in the coordination sphere. As erbium concentration is increased, the high AlO(6) coordinated class of sites is smeared out by the optical response of the one AlO(6) coordinated class of sites. PMID:20940961

  17. Numerical simulation and optimization of passively q-switched erbium microchip lasers

    NASA Astrophysics Data System (ADS)

    Belghachem, Nabil; Mlynczak, Jarslow

    2015-08-01

    In this article we present a procedure of optimization of passively q-switched erbium microchip lasers. The procedure is based on the rate equation model, validated by comparing the numerical results to the experimental results of pulse generation in different types of erbium/ytterbium glass microchips q-switched by Co2+ : MgAl2O4 saturable absorber. Some Degnan’s optimization limitations in case of microchip lasers were also shown and the reabsorbtion cross section of erbium glass was also estimated.

  18. Influence of water environment on holmium laser ablation performance for hard tissues.

    PubMed

    Lü, Tao; Xiao, Qing; Li, Zhengjia

    2012-05-01

    This study clarifies the ablation differences in air and in water for hard biological tissues, which are irradiated by fiber-guided long-pulsed holmium lasers. High-speed photography is used to record the dynamic characteristics of ablation plumes and vaporization bubbles induced by pulsed holmium lasers. The ablation morphologies and depth of hard tissues are quantitatively measured by optical coherence microscopy. Explosive vaporization effects in water play a positive role in the contact ablation process and are directly responsible for significant ablation enhancement. Furthermore, water layer depth can also contribute to ablation performance. Under the same laser parameters for fiber-tissue contact ablation in air and water, ablation performances are comparable for a single-laser pulse, but for more laser pulses the ablation performances in water are better than those in air. Comprehensive knowledge of ablation differences under various environments is important, especially in medical procedures that are performed in a liquid environment. PMID:22614434

  19. Solubility product and thermodynamic functions for the holmium trifluoride - water system

    SciTech Connect

    Menon, M.P.; James, J.; Hill, T.L. )

    1988-01-01

    The total solubility, free ion concentrations in saturated solutions, solubility products and thermodynamic functions for the dissolution of holmium trifluoride hemihydrate together with the stability constants for the holmium mono- and diflouride complexes are reported in this paper. Conductometric and potentiometric methods were used to measure the solubilities for comparison of the results obtained therefrom. Our values for pK{sub SO}, the thermodynamic solubility product in terms of free ion concentrations of both ions, obtained from both methods are in agreement with one of the reported values. There are no values reported in the literature for the thermodynamic constants for the dissolution process to be compared with except for entropy change. Our values for the stability constants, measured by a simplified procedure, do not agree with those reported by previous authors.

  20. Medium-energy ion-scattering study of strained holmium silicide nanoislands grown on silicon (100)

    NASA Astrophysics Data System (ADS)

    Wood, T. J.; Eames, C.; Bonet, C.; Reakes, M. B.; Noakes, T. C. Q.; Bailey, P.; Tear, S. P.

    2008-07-01

    We have used medium-energy ion scattering (MEIS) to quantitatively analyze the structure of holmium silicide islands grown on the Si(100) surface. Structure fitting to the experimental data unambiguously shows that the tetragonal silicide phase is present and not the hexagonal phase, which is associated with the growth of nanowires at submonolayer coverages. Islands formed with a lower holmium coverage of 3 ML are also shown to be tetragonal, which suggests that the hexagonal structure is not a low coverage precursor to the growth of the tetragonal phase. MEIS simulations of large nanoislands, which include the effects of lateral strain relief, have been performed and these compare well with the experimental data.

  1. Quantitative Monte Carlo-based holmium-166 SPECT reconstruction

    SciTech Connect

    Elschot, Mattijs; Smits, Maarten L. J.; Nijsen, Johannes F. W.; Lam, Marnix G. E. H.; Zonnenberg, Bernard A.; Bosch, Maurice A. A. J. van den; Jong, Hugo W. A. M. de; Viergever, Max A.

    2013-11-15

    Purpose: Quantitative imaging of the radionuclide distribution is of increasing interest for microsphere radioembolization (RE) of liver malignancies, to aid treatment planning and dosimetry. For this purpose, holmium-166 ({sup 166}Ho) microspheres have been developed, which can be visualized with a gamma camera. The objective of this work is to develop and evaluate a new reconstruction method for quantitative {sup 166}Ho SPECT, including Monte Carlo-based modeling of photon contributions from the full energy spectrum.Methods: A fast Monte Carlo (MC) simulator was developed for simulation of {sup 166}Ho projection images and incorporated in a statistical reconstruction algorithm (SPECT-fMC). Photon scatter and attenuation for all photons sampled from the full {sup 166}Ho energy spectrum were modeled during reconstruction by Monte Carlo simulations. The energy- and distance-dependent collimator-detector response was modeled using precalculated convolution kernels. Phantom experiments were performed to quantitatively evaluate image contrast, image noise, count errors, and activity recovery coefficients (ARCs) of SPECT-fMC in comparison with those of an energy window-based method for correction of down-scattered high-energy photons (SPECT-DSW) and a previously presented hybrid method that combines MC simulation of photopeak scatter with energy window-based estimation of down-scattered high-energy contributions (SPECT-ppMC+DSW). Additionally, the impact of SPECT-fMC on whole-body recovered activities (A{sup est}) and estimated radiation absorbed doses was evaluated using clinical SPECT data of six {sup 166}Ho RE patients.Results: At the same noise level, SPECT-fMC images showed substantially higher contrast than SPECT-DSW and SPECT-ppMC+DSW in spheres ≥17 mm in diameter. The count error was reduced from 29% (SPECT-DSW) and 25% (SPECT-ppMC+DSW) to 12% (SPECT-fMC). ARCs in five spherical volumes of 1.96–106.21 ml were improved from 32%–63% (SPECT-DSW) and 50%–80

  2. Separation of carrier-free holmium-166 from neutron-irradiated dysprosium targets

    SciTech Connect

    Dadachova, E.; Lambrecht, R.M.; Hetherington, E.L. ); Mirzadeh, S.; Knapp, F.F. Jr. )

    1994-12-01

    Holmium-166 ([sup 166]Ho, t[sub 1/2] = 26.4 h) is utilized in radiotherapeutic applications such as radioimmunospecific pharmaceuticals, bone marrow ablation, and radiation synovectomy. High specific activity [sup 166]Ho can be obtained from the decay of dysprosium-166 ([sup 166]Dy, t[sub 1/2] = 81.5 h). Dysprosium-166 is produced by the [sup 164]Dy[n,[gamma

  3. Mathematical modelling of dispersion-managed thulium/holmium fibre lasers

    SciTech Connect

    Yarutkina, I A; Shtyrina, O V

    2013-11-30

    The mathematical model of a dispersion-managed thulium/holmium fibre laser is described; the results of numerical calculations and their comparison with the experimental data are presented. Qualitative agreement of the results of the mathematical modelling with those of the experiment is obtained. Using the methods of mathematical modelling, the variation in the characteristics of the optical pulses due to the change in the average cavity dispersion is analysed. (control of laser radiation parameters)

  4. Laser Prostatectomy: Holmium Laser Enucleation and Photoselective Laser Vaporization of the Prostate

    PubMed Central

    Bostanci, Yakup; Kazzazi, Amir; Djavan, Bob

    2013-01-01

    Historically, transurethral resection of the prostate has been the gold standard for the treatment of benign prostatic hyperplasia (BPH). Laser technology has been used to treat BPH for > 15 years. Over the past decade, it has gained wide acceptance by experienced urologists. This review provides an evidence-based update on laser surgery for BPH with a focus on photoselective laser vaporization and holmium laser enucleation of the prostate surgeries and assesses the safety, efficacy, and durability of these techniques. PMID:23671400

  5. Successful treatment of recurrent vesicourethral stricture after radical prostatectomy with holmium laser: report of three cases.

    PubMed

    Hayashi, Tetsuo; Yoshinaga, Atsushi; Ohno, Rena; Ishii, Nobuyuki; Watanabe, Toru; Yamada, Takumi; Kihara, Kazunori

    2005-04-01

    We report three cases with severe anastomotic strictures, which recurred several times after radical prostatectomy despite repeated treatments of urethral dilation, internal urethrotomy and/or transurethral resection. All three cases were finally treated with holmium laser successfully without any intraoperative or postoperative complications after repeated failures of each treatment. There were two specific characteristics in these three cases: the early onset of the stricture and the pinhole opening located on the top (12-o'clock) of the stricture wall. PMID:15948734

  6. Obliterated urethra: holmium:yttrium-aluminum-garnet cut-to-light with urolume stenting.

    PubMed

    Monga, M; Gordon, Z; Alexandrescu, B

    2001-12-01

    Antegrade-retrograde urethrotomy, or the cut-to-light procedure, performed for obliterated urethra is associated with a high rate of recurrence of urethra] stricture. With the goal of reducing the stricture recurrence rate, we performed a modified cut-to-light procedure using a holmium:yttrium-aluminum-garnet laser and UroLume stenting in a 76-year-old man with urethral obliteration. PMID:11763485

  7. Holmium:YAG laser-assisted otolaryngologic surgery: Lahey Clinic experience

    NASA Astrophysics Data System (ADS)

    Shapshay, Stanley M.; Rebeiz, Elie E.; Pankratov, Michail M.

    1993-07-01

    The Holmium:YAG laser was used to assist in 36 rhinologic procedures including surgery for chronic sinus disease, chronic dacryocystitis, recurrent choanal stenosis, and a sphenoid sinus mucocele. There were no laser related complications. The laser permitted controlled ablation of bone and soft tissue in all cases with satisfactory results. The Ho:YAG laser can be used in otolaryngology to assist in cases where surgical access is difficult or when controlled, precise bone and soft tissue ablation is necessary.

  8. Holmium laser enucleation of the prostate: a review of the clinical trial evidence.

    PubMed

    Cynk, Mark

    2014-04-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  9. Holmium laser enucleation of the prostate: a review of the clinical trial evidence

    PubMed Central

    2014-01-01

    Transurethral resection of the prostate (TURP) has remained the procedure of choice for the surgical treatment of bladder outflow obstruction for almost five decades, but holmium laser enucleation of the prostate (HoLEP) is now emerging as a challenger as the gold standard procedure. This review summarizes the evidence base for HoLEP, with particular reference to randomized, controlled (level 1) evidence. PMID:24688602

  10. Efficient holmium:yttrium lithium fluoride laser longitudinally pumped by a semiconductor laser array

    NASA Technical Reports Server (NTRS)

    Hemmati, H.

    1987-01-01

    Optical pumping of a holmium:yttrium lithium floride (Ho:YLF) crystal with a 790-nm continuous-wave diode-laser array has generated 56 mW of 2.1-micron laser radiation with an optical-to-optical conversion slope efficiency of 33 percent while the crystal temperature is held at 77 K. The lasing threshold occurs at 7 mW of input power, and laser operation continues up to a crystal temperature of 124 K.

  11. Crystal structure and optical study of praseodymium polyphosphate Pr(PO{sub 3}){sub 3}

    SciTech Connect

    Jouini, Anis; Ferid, Mokhtar; Gacon, Jean-Claude; Grosvalet, Laurent; Thozet, Alain; Trabelsi-Ayadi, Malika

    2003-10-01

    Single crystals of praseodymium polyphosphate Pr(PO{sub 3}){sub 3} were grown for the first time using a flux method and characterized by single-crystal X-ray diffraction. Pr(PO{sub 3}){sub 3} is isostructural with Nd(PO{sub 3}){sub 3} and La(PO{sub 3}){sub 3}. It crystallizes in the orthorhombic system with space group C222{sub 1} (D{sub 2}{sup 5}), with lattice parameters: a=11.234(1) A, b=8.5289(8) A, c=7.3199(8) A. The crystal structure was resolved with final R(F{sup 2})=0.0359 and R{sub w}(F{sup 2})=0.0924 for 402 independent reflections (F{sub 0}{sup 2}{>=}2{sigma}(F{sub 0}{sup 2})). In the Pr(PO{sub 3}){sub 3} structure, oxygen atoms form a PO{sub 4} tetrahedron around each P atom and a PrO{sub 8} polyhedron around each Pr atom. The PO{sub 4} tetrahedra share corners to produce helical chains and the PrO{sub 8} polyhedra share edges to form zigzag chains. The shortest Pr-Pr distance is 4.253 A. The energies of the vibrational modes of the crystal are obtained from the infrared and Raman spectra. Measurements of emission spectra under pulsed laser excitation in the Pr{sup 3+} (4f{sup 2}) {sup 3}P{sub J} (J=0, 1, 2) levels and decay times of the observed emissions are reported both at room and liquid-helium temperatures. X-ray excitation leads to intense ultraviolet 4f{sup 1}5d{sup 1}{yields}4f{sup 2} band emissions in the 200-300 nm spectral range with decay times in the order of 6 ns both at room and low temperatures.

  12. Soft-tissue applications of the holmium:YAG laser in urology

    NASA Astrophysics Data System (ADS)

    Denstedt, John D.; Razvi, Hassan A.; Chun, Samuel S.; Sales, Jack L.

    1995-05-01

    The ideal surgical laser for the treatment of soft tissue pathology should possess both ablative and hemostatic abilities. As well, for use in urologic conditions the laser must also be suitable for endoscopic use. The Holmium:YAG laser possesses these qualities and in preliminary clinical use has demonstrated a variety of potential urologic applications. In this study we review our initial experience with the Holmium:YAG laser over a 18 month period. A total of 51 patients underwent 53 procedures for a variety of soft tissue conditions including: bladder tumor ablation (25), incision of ureteral stricture (15), incision of urethral stricture (6), treatment of ureteropelvic junction obstruction (3), incision of bladder neck contracture (2), and ablation of a ureteral tumor (2). Satisfactory hemostasis was achieved in all cases. Procedures were considered successful (no further intervention being required to treat the condition) in 81% of the cases. Two patients with dense bladder neck contractures required electroincision under the same anesthetic for completion of the procedure. A single complication, that of urinary extravasation following incision of a urethral stricture resolved with conservative management. In summary, the Holmium:YAG laser has demonstrated safety and proficiency in the treatment of a variety of urologic soft tissue conditions.

  13. Laser angioplasty with lensed fibers and a holmium:YAG laser in iliac artery occlusions

    NASA Astrophysics Data System (ADS)

    White, Christopher J.; Ramee, Stephen R.; Mesa, Juan E.; Collins, Tyrone J.; Kotmel, Robert; Godfrey, Maureen A.

    1991-05-01

    Holmium-YAG (2.1 (mu) ) laser recanalization was attempted in 10 totally occluded miniature swine iliac arteries using a lensed fiber delivery system. The iliac artery occlusions were created in a Yucatan miniature swine model of atherosclerosis by means of a high cholesterol diet and balloon endothelial denudation. In order to increase the spot size, a spherical silica lens was attached to the distal end of a 300 micrometers core diameter silica optical fiber. The holmium-YAG laser was operated in the free-running mode with 250 microsecond(s) ec pulses at 4 Hz. The energy delivered was 225 mJ per pulse for the 1.0 mm lensed fiber and 200 mJ per pulse for the 1.3 mm lensed fiber. Laser energy was delivered in 2 to 5 second bursts. Successful recanalization was achieved in all 10 arteries attempted without perforation of the arterial wall. The average length of the occlusions was 5.0 +/- 1.8 cm. Following successful laser recanalization significant stenoses (>50%) remained in all of the arteries as judged by angiography. In conclusion, the lensed fibers coupled to the pulsed holmium-YAG laser were safe and effective in recanalizing these difficult lesions in relatively straight iliac arteries. There is potential clinical utility for this system as an adjunct to balloon angioplasty in patients with lesions which are unable to be crossed with guidewires.

  14. Radiation-resistant erbium-doped-nanoparticles optical fiber for space applications.

    PubMed

    Thomas, Jérémie; Myara, Mikhaël; Troussellier, Laurent; Burov, Ekaterina; Pastouret, Alain; Boivin, David; Mélin, Gilles; Gilard, Olivier; Sotom, Michel; Signoret, Philippe

    2012-01-30

    We demonstrate for the first time a radiation-resistant Erbium-Doped Fiber exhibiting performances that can fill the requirements of Erbium-Doped Fiber Amplifiers for space applications. This is based on an Aluminum co-doping atom reduction enabled by Nanoparticules Doping-Process. For this purpose, we developed several fibers containing very different erbium and aluminum concentrations, and tested them in the same optical amplifier configuration. This work allows to bring to the fore a highly radiation resistant Erbium-doped pure silica optical fiber exhibiting a low quenching level. This result is an important step as the EDFA is increasingly recognized as an enabling technology for the extensive use of photonic sub-systems in future satellites. PMID:22330481

  15. Erbium doping of lithium niobate by the ion exchange process for high-gain optical amplifiers

    NASA Astrophysics Data System (ADS)

    Caccavale, Frederico; Fedorov, Vyacheslav A.; Korkishko, Yuri N.; Morozova, Tamara V.; Sada, Cinzia; Segato, Francesco

    2000-04-01

    The erbium-lithium ion exchange is presented as a method for the erbium local doping of lithium niobate crystals. Ion exchange process is performed immersing the LiNbO3 substrates in a liquid melt, containing erbium ions; due to their high mobility, the lithium ions migrate from the crystal to the melt, and are replaced by erbium ions. A systematic analysis of the doping process is performed, and the influence of the process parameters is investigated: exchange time and temperature, crystal cut direction, composition and chemical reactivity of the Er ions liquid source. By structural (X-Ray Diffraction and Rutherford Backscattering Spectrometry), compositional (Secondary Ion Mass Spectrometry) and spectroscopic techniques (optical spectroscopy and micro-luminescence), the formation of lithium deficient phases and the incorporation of the Er ions into the LiNbO3 matrix is studied.

  16. Erbium localized doping into various cuts of lithium niobate and sapphire: a comparative study

    NASA Astrophysics Data System (ADS)

    Nekvindova, Pavla; Mackova, Anna; Perina, Vratislav; Cervena, Jarmila; Capek, Pavel; Schroefel, Josef; Spirkova, Jarmila; Oswald, Jiri

    2003-07-01

    Medium temperature (350 °C) localized doping of Er3+ was studied in lithium niobate (LN) and sapphire single crystal wafers that were cut in various crystallographic directions. It was found that the efficiency of the doping was connected with orientations of the substrate wafers of both LN and sapphire, and with the presence of mobile lithium ions in the structure of LN. The basic interstitial mechanism of erbium incorporation into the structure of sapphire and LN is in the latter accompanied with erbium for lithium ion exchange. While the rate of the interstitial diffusion was higher in the wafers oriented perpendicularly towards the cleavage planes of the crystals, ion exchange process was significant in the wafers cut in cleavage planes. Waveguiding properties in erbium doped lithium niobate originated rather from presence of erbium in the structure of the crystals than being a consequence of a weak proton exchange. Luminescence properties of the fabricated samples are also presented.

  17. Long lifetime, high density single-crystal erbium compound nanowires as a high optical gain material

    NASA Astrophysics Data System (ADS)

    Yin, Leijun; Ning, Hao; Turkdogan, Sunay; Liu, Zhicheng; Nichols, Patricia L.; Ning, C. Z.

    2012-06-01

    Erbium-containing materials of long lifetime and high Er density are important for achieving strong luminescence and high optical gain in compact integrated photonics devices. We have systematically studied the lifetime and crystal quality as a function of growth conditions for an erbium compound that we recently reported, erbium chloride silicate (ECS). The lifetime for the best quality ECS nanowires can be as long as 540 μs, the longest for high-density Er-materials, representing a lifetime-density product as high as 8.7 × 1018 s cm-3. Such high density, long lifetime erbium materials can find many interesting applications such as compact lasers or amplifiers.

  18. Generalized rate-equation analysis of excitation exchange between silicon nanoclusters and erbium ions

    SciTech Connect

    Kenyon, A. J.; Wojdak, M.; Ahmad, I.; Loh, W. H.; Oton, C. J.

    2008-01-15

    We discuss the use of rate equations to analyze the sensitization of erbium luminescence by silicon nanoclusters. In applying the general form of second-order coupled rate-equations to the Si nanocluster-erbium system, we find that the photoluminescence dynamics cannot be described using a simple rate equation model. Both rise and fall times exhibit a stretched exponential behavior, which we propose arises from a combination of a strongly distance-dependent nanocluster-erbium interaction, along with the finite size distribution and indirect band gap of the silicon nanoclusters. Furthermore, the low fraction of erbium ions that can be excited nonresonantly is a result of the small number of ions coupled to nanoclusters.

  19. Generation of white-light through frequency upconversion in praseodymium-ytterbium codoped nano-structured fluorogermanate glass

    NASA Astrophysics Data System (ADS)

    Gouveia-Neto, Artur S.; Rios, Nathalia P. S. M.; Bueno, Luciano A.

    2012-02-01

    Praseodymium-ytterbium codoped fluorogermanate nano-structured phosphors for solid-state lighting were synthesized by thermal treatment of precursor glasses. Room temperature luminescence features of praseodymium-ytterbium ions incorporated into low-phonon-energy PbF2 nanocrystals dispersed into the fluorogermanate glass matrix and excited with near-infrared light emitting diode laser was evaluated. The luminescence spectra exhibited predominant emissions in the 475-500, 520-530, and 600-650 nm regions. White-light emission was observed in ytterbium-sensitized praseodymiumdoped phosphor excited at 980 nm. The dependence of the luminescence emisson intensity upon annealing temperature, and rare-earth concentrations was also evaluated. The results indicated that there exist an optimum annealing temperature and activator ion concentration in order to obtain efficient upconversion emission signals with CIE 1946 chromaticity coordinates within the white-light borderline region. Results indicate that the nanocomposite fluorogermanate glassy phosphor is a promissing novel contender for application in white-light solid-state display technology

  20. Selective determination of the holmium in rare earth mixtures by second derivative spectrophotometry with 2-isobutylformyl-1,3-dione-indan and octylphenol poly-(ethyleneglycol)ether

    SciTech Connect

    Wang Naixing; Si Zhikun; Jiang Wei

    1996-09-01

    In this paper the absorption spectra of 4f electron transitions of the system of holmium with 2-isobutylformyl-1,3-dione-indan and TX-100 have been studied by normal and derivative spectrophotometry. The molar absorptivities are 98 (at 450 nm) and 21 (at 460 nm) 1 {center_dot} mol{sup -1} {center_dot} cm{sup -1}, respectively. The use of the second derivative spectra, eliminates the interference by other lanthanides and improves the sensitivity for holmium determination. The derivative molar absorptivity is 558 1 {center_dot} mol{sup -1} {center_dot} cm{sup -1}. The calibration graph was linear up to 25{mu}g/ml of holmium. The relative standard deviation evaluated from ten independent determinations of 8.0 {mu}g/ml holmium is 1.0%. The detection limit, obtained from the sensitivity of the calibration graph and for 3 S{sub b} (S{sub b} = standard deviation of a blank without holmium, n = 11), was found to be 0.31 {mu}g/ml of holmium. The quantification limit, obtained for 10 S{sub b}, was 1.0 {mu}g/ml of holmium. A method has been developed for determining holmium in a mixture of lanthanides by means of the second derivative spectra and the analytical results obtained are satisfactory.

  1. Resonantly photo-pumped nickel-like erbium X-ray laser

    DOEpatents

    Nilsen, Joseph

    1990-01-01

    A resonantly photo-pumped X-ray laser (10) that enhances the gain of seve laser lines that also lase because of collisional excitations and recombination processes, is described. The laser comprises an aluminum (12) and erbium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like erbium ions (34) are resonantly photo-pumped by line emission from hydrogen-like aluminum ions (32).

  2. Ureteroscopy and holmium:YAG laser lithotripsy: an emerging definitive management strategy for symptomatic ureteral calculi in pregnancy

    NASA Astrophysics Data System (ADS)

    Watterson, James D.; Girvan, Andrew R.; Beiko, Darren T.; Nott, Linda; Wollin, Timothy A.; Razvi, Hassan A.; Denstedt, John D.

    2003-06-01

    Objectives: Symptomatic urolithiasis in pregnancy that does not respond to conservative measures has traditionally been managed with ureteral stent insertion or percutaneous nephrostomy (PCN). Holmium:yttrium-aluminum-garnet (YAG) laser lithotripsy using state-of-the-art ureteroscopes represents an emerging strategy for definitive stone management in pregnancy. The purpose of this study was to review the results of holmium laser lithotripsy in a cohort of patients who presented with symptomatic urolithiasis in pregnancy. Methods: A retrospective analysis was conducted at 2 tertiary stone centers from January 1996 to August 2001 to identify pregnant patients who were treated with ureteroscopic holmium laser lithotripsy for symptomatic urolithiasis or encrusted stents. Eight patients with a total of 10 symptomatic ureteral calculi and 2 encrusted ureteral stents were treated. Mean gestational age at presentation was 22 weeks. Mean stone size was 8.1 mm. Stones were located in the proximal ureter/ureteropelvic junction (UPJ) (3), mid ureter (1), and distal ureter (6). Results: Complete stone fragmentation and/or removal of encrusted ureteral stents were achieved in all patients using the holmium:YAG laser. The overall procedural success rate was 91%. The overall stone-free rate was 89%. No obstetrical or urological complications were encountered. Conclusions: Ureteroscopy and holmium laser lithotripsy can be performed safely in all stages of pregnancy providing definitive management of symptomatic ureteral calculi. The procedure can be done with minimal or no fluoroscopy and avoids the undesirable features of stents or nephrostomy tubes.

  3. Dual-kind Q-switching of erbium fiber laser

    SciTech Connect

    Barmenkov, Yuri O. Kir'yanov, Alexander V.; Cruz, Jose L.; Andres, Miguel V.

    2014-03-03

    Two different regimes of Q-switching in the same implementation of an actively Q-switched erbium-doped fiber laser are demonstrated. Depending on the active fiber length and repetition rate of an intracavity Q-cell (acousto-optic modulator), the laser operates either in the regime of common, rather long and low-power, pulses composed of several sub-pulses or in the one of very short and powerful stimulated Brillouin scattering-induced pulses. The basic physical reason of the laser system to oscillate in one of these two regimes is the existence or absence of CW narrow-line “bad-cavity” lasing in the intervals when the Q-cell is blocked.

  4. Enhanced near-infrared-luminescence in an erbium tetrafluoroterephthalate framework.

    PubMed

    Chen, Banglin; Yang, Yu; Zapata, Fatima; Qian, Guodong; Luo, Yongshi; Zhang, Jiahua; Lobkovsky, Emil B

    2006-10-30

    Two erbium-organic frameworks Er2(BDC)3(DMF)2(H2O)2.H2O (1) and Er2(BDC-F4)3(DMF)(H2O).DMF (2) (BDC = 1,4-benzenedicarboxylate; BDC-F(4) = 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylate or tetrafluoroterephthalate; DMF = dimethylformamide) have been synthesized and structurally characterized. Studies on thermal gravimetric analysis and the spectroscopic and luminescent properties of 1, 2, and their desolvated solid Er2(BDC)3 (1a) and partially desolvated solid Er2(BDC-F4)3(DMF).DMF (2a) indicate that fluorination can significantly improve the luminescence intensity of the Er ions by reducing the fluorescence quenching effect of the vibrational C-H bond; thus, the near-IR-luminescence intensity of 2a is 3 times higher than that of 1a. PMID:17054346

  5. Analytical interactomic potential for a molybdenum–erbium system

    NASA Astrophysics Data System (ADS)

    Sun, Q. Q.; Yang, T. L.; Yang, L.; Peng, S. M.; Long, X. G.; Zhou, X. S.; Zu, X. T.; Gao, F.

    2016-05-01

    Analytical interatomic potentials of a molybdenum–erbium (Mo–Er) system are developed based on a Tersoff–Brenner-type form. The potentials well describes the bulk and defect properties of bcc Mo, including lattice parameter, cohesive energy, elastic constants, formation energies of point defects, surface energies and melting point. The adsorption behavior of Er on a Mo (1 1 0) surface is studied using ab initio calculations based on the density functional theory, which is used to fit the interatomic potential of a Mo–Er interaction. The growth mechanism of the Er film on a Mo substrate is investigated using the present potentials. The simulation results show that the microstructures and morphologies of Er films are sensitive to substrate temperatures. Columnar grains of hexagonal close-packed Er parallel to a Mo (1 1 0) surface are observed and the grain sizes increase with increasing substrate temperature.

  6. Passive mode locking in erbium-ytterbium fiber lasers

    NASA Astrophysics Data System (ADS)

    Thai, Serey; Hayduk, Michael J.

    1999-11-01

    A novel mode-locked erbium-ytterbium fiber laser operating at 1550 nm using multiple quantum well (MQW) saturable absorbers was developed. The laser was constructed in a Fabry-Perot configuration using a fiber Bragg grating as a front reflector and a fiber Bragg grating output as a back reflector of the laser cavity. The passive mode-locking element placed inside the laser cavity is a 75 period InGaAs/InAlAs MQW saturable absorber grown lattice matched on an InP substrate. The output of the laser was taken through the other available port of a wavelength-division demultiplexer. The laser produced mode-locked output pulse trains at 16.67-MHz repetition rate and 10 mW of average output power.

  7. Microwave multimode memory with an erbium spin ensemble

    NASA Astrophysics Data System (ADS)

    Probst, S.; Rotzinger, H.; Ustinov, A. V.; Bushev, P. A.

    2015-07-01

    Hybrid quantum systems combining circuit QED with spin-doped solids are an attractive platform for distributed quantum information processing. There, the magnetic ions serve as coherent memory elements and reversible conversion elements of microwave to optical qubits. Among many possible spin-doped solids, erbium ions offer the unique opportunity for a coherent conversion of microwave photons into the telecom C band at 1.54 μ m employed for long distance communication. In our work, we perform a time-resolved electron spin resonance study of an Er3 +:Y2SiO5 spin ensemble at millidegrees Kelvin temperatures and demonstrate multimode storage and retrieval of up to 16 coherent microwave pulses. The memory efficiency is measured to be 10-4 at a coherence time of T2=5.6 μ s . We observe a saturation of the spin coherence time below 50 mK due to full polarization of the surrounding electronic spin bath.

  8. Ion implantation of erbium into polycrystalline cadmium telluride

    SciTech Connect

    Ushakov, V. V. Klevkov, Yu. V.; Dravin, V. A.

    2015-05-15

    The specific features of the ion implantation of polycrystalline cadmium telluride with grains 20–1000 μm in dimensions are studied. The choice of erbium is motivated by the possibility of using rare-earth elements as luminescent “probes” in studies of the defect and impurity composition of materials and modification of the composition by various technological treatments. From the microphotoluminescence data, it is found that, with decreasing crystal-grain dimensions, the degree of radiation stability of the material is increased. Microphotoluminescence topography of the samples shows the efficiency of the rare-earth probe in detecting regions with higher impurity and defect concentrations, including regions of intergrain boundaries.

  9. An Erbium Quantum Gas Microscope with a Reflective Objective

    NASA Astrophysics Data System (ADS)

    Krahn, Aaron; Phelps, Gregory; Hebert, Anne; Dickerson, Susannah; Greiner, Markus; Erbium Lab Team

    2016-05-01

    Dipolar atoms present an exciting opportunity to extend previous quantum gas microscope (QGM) experiments to more complex systems influenced by long range, anisotropic interactions. We present on current progress toward the construction of a QGM for ultracold Erbium atoms in an optical lattice, including the development of a novel imaging system for single-site resolution. While most QGMs until now have typically utilized a high numerical aperture microscope objective, we discuss a reflective mirror alternative that offers an equally high NA (.9-.95), a comparable field of view (34 micrometers radial), and a larger working distance (25 millimeters) that keeps the atoms far from any surfaces. By operating in a Schmidt telescope configuration, this imaging system is well-suited both for collecting 401 nm imaging fluorescence and for the creation of an expandable lattice with a variety of associated lattice geometries.

  10. Stable dual-wavelength erbium fiber laser for temperature measurements

    NASA Astrophysics Data System (ADS)

    Diaz, S.; Lopez-Amo, M.

    2015-09-01

    In this work, a new stable dual-wavelength erbium fiber ring laser is proposed and experimentally demonstrated. This configuration is made by creating two symmetrical laser cavities with similar optical power. This topology allows the performance of two laser emission lines in single-longitudinal mode and with a power instability lower than 0.23 dB, and an optical signal-to-noise ratio higher than 40 dB for all the emitted wavelengths. The sensing capability of the FBGs enables this source to be also used as sensor-network multiplexing scheme. The system offers a better stability and higher optical signal to noise ratios than similar configurations.

  11. Nanoscale nonlinear effects in Erbium-implanted Yttrium Orthosilicate

    NASA Astrophysics Data System (ADS)

    Kukharchyk, Nadezhda; Shvarkov, Stepan; Probst, Sebastian; Xia, Kangwei; Becker, Hans-Werner; Pal, Shovon; Markmann, Sergej; Kolesov, Roman; Siyushev, Petr; Wrachtrup, Jörg; Ludwig, Arne; Ustinov, Alexey V.; Wieck, Andreas D.; Bushev, Pavel

    2016-09-01

    Doping of substrates at desired locations is a key technology for spin-based quantum memory devices. Focused ion beam implantation is well-suited for this task due to its high spacial resolution. In this work, we investigate ion-beam implanted erbium ensembles in Yttrium Orthosilicate crystals by means of confocal photoluminescence spectroscopy. The sample temperature and the post-implantation annealing step strongly reverberate in the properties of the implanted ions. We find that hot implantation leads to a higher activation rate of the ions. At high enough fluences, the relation between the fluence and final concentration of ions becomes non-linear. Two models are developed explaining the observed behaviour.

  12. Site-selective spectroscopy of the solid-state defect chemistry in erbium-doped barium titanate.

    PubMed

    Bak, John D; Wright, John C

    2005-10-01

    Erbium-doped barium titanate crystals were studied by laser-induced fluorescence spectroscopy. Thirteen spectroscopically distinct erbium ion sites were found. The relative concentrations of the different sites changed as a function of the crystal and its preparation and treatment. One major site was present in all crystals. The site distribution was changed either by growing codoped crystals with donor (La3+) and acceptor (Sc3+) ions or by changing the temperature and partial pressure of the oxygen in the annealing atmosphere. Equilibrium calculations were done to simulate the defect distributions that result from the charge compensation of the erbium ions. Comparison with the observed dependence of the site spectral intensities indicated that the erbium enters the lattice on barium sites. We assigned the dominant site to an erbium ion on a barium site that is locally compensated by a barium vacancy, whereas the other lower-intensity sites corresponded to erbium ions that are locally compensated by an electron and a more complex center of an erbium, a barium vacancy, and a hole. The spectra of one sample showed that its defects were different and were characteristic of a sample that had not equilibrated. The new sites in this sample were assigned to erbium entering the lattice on a titanium site, which was then locally compensated by an oxygen vacancy or a hole. Heating equilibrated the sample and changed the erbium to a barium site. PMID:16853368

  13. New, efficient, room temperature mid-infrared laser at 3.9 mu m in holmium:barium yttrium fluoride and visible praseodymium:lithium yttrium fluoride laser for holography

    NASA Astrophysics Data System (ADS)

    Tabirian, Anna Murazian

    This dissertation describes a series of experiments and theoretical studies, which led to the development of two new solid state laser systems: efficient, room temperature mid-infrared solid state laser at 3.9 μm in Ho 3+ doped BaY2F8 and visible Pr:LiYF4 laser at 640 mn for holography. The 3.9 μm laser wavelength matches the peak of mid-IR atmospheric transmission window, which makes it very important for multiple applications such as remote sensing, imaging, IR countermeasures, eye-safe lidars and environmental agent detection. We present the results of spectroscopic evaluations and numerical modeling of energy transfer processes between rare earth ions of Ho3+ doped in two host laser materials: BaY2F8 and LiYF 4. The 3.9 μm laser is based on transition with upper laser lifetime considerably shorter than lower level lifetime, which in general leads to self-terminating laser action in the cw mode or at high repetition rates. Therefore, three different pumping and lasing schemes, that could allow overcoming these limitations have been suggested and studied. First, cascade laser action at 1.4 μm and 3.9 μm was achieved with low thresholds and near-theoretical quantum efficiency in Ho3+ doped BaY2F8 pumped at 532 nm by a Q- switched frequency doubled Nd:YAG laser. Next, the feasibility of achieving 3.9 μm laser with cw resonant cascade pumping at 750 mn by a Ti:Sapphire laser was studied. New energy transfer process, such as upconversion from terminal level of the 3.9 μm laser was observed in high concentration Ho3+ doped BaY2F 8. Finally, we proposed to use high-energy flashlamp pumped tunable Cr:LiSAF laser operating in long pulse regime for the direct pumping of the upper level of the 3.9 μm laser. Pulsed laser oscillation at 3.9 μm is demonstrated in Ho3+ doped BaY2F8 with low threshold of 3 mJ and a slope efficiency of 14.5% with maximal energy of 30 mJ. The second part of the thesis describes the design and the development of the visible Pr:LiYF4 laser for holography at 640 nm resonantly pumped by the frequency-doubled flashlamp pumped tunable Cr:LiSAF laser at 444 nm.

  14. Retrograde flexible ureterorenoscopic holmium-YAG laser lithotripsy: the new gold standard.

    PubMed

    Gould, D L

    1998-03-01

    To demonstrate the efficacy of flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy for the treatment of renal calculi, a total of 86 patients presenting to our hospital with renal calculi underwent flexible retrograde ureterorenoscopic holmium-YAG intracorporeal laser lithotripsy of their stones, and the data were collected prospectively. As extracorporeal shock wave lithotripsy is not available at our institution, all patients with renal calculi in this study were treated in a retrograde fashion using the Richard Wolf 6.0F semirigid ureteroscope, the 7.5F flexible ureterorenoscope, and the holmium-YAG laser by Coherent Inc. Except for inhospital consults or patients requiring admission secondary to infection, all cases were performed on an ambulatory basis. All renal calculi 3 cm or smaller were approached in a retrograde fashion. Where possible, the stones were initially debulked using the semirigid ureteroscope and the 550-microm fiber followed by the flexible ureterorenoscope in combination with the 360- or 200-microm laser fiber depending on stone position. Stones were fragmented until they were small enough to be removed by hydrocleansing. Using this technique, stone-free success rates for calculi 2.5 cm or smaller after a single treatment, regardless of stone composition or location, are superior to those of extracorporeal shock wave lithotripsy. For calculi between 2.5 and 3 cm, the results also are noted to be superior. We conclude that for calculi larger than 3 cm or for partial staghorn calculi, the treatment of choice appears to be a percutaneous approach. PMID:9568772

  15. Percutaneous Endoscopic Holmium Laser Lithotripsy for Management of Complicated Biliary Calculi

    PubMed Central

    Healy, Kelly; Chamsuddin, Abbas; Spivey, James; Martin, Louis; Nieh, Peter

    2009-01-01

    Background and Objectives: Advances in endoscopic techniques have transformed the management of urolithiasis. We sought to evaluate the role of such urological interventions for the treatment of complex biliary calculi. Methods: We conducted a retrospective review of all patients (n=9) undergoing percutaneous holmium laser lithotripsy for complicated biliary calculi over a 4-year period (12/2003 to 12/2007). All previously failed standard techniques include ERCP with sphincterotomy (n=6), PTHC (n=7), or both of these. Access to the biliary system was obtained via an existing percutaneous transhepatic catheter or T-tube tracts. Endoscopic holmium laser lithotripsy was performed via a flexible cystoscope or ureteroscope. Stone clearance was confirmed intra- and postoperatively. A percutaneous transhepatic drain was left indwelling for follow-up imaging. Results: Mean patient age was 65.6 years (range, 38 to 92). Total stone burden ranged from 1.7 cm to 5 cm. All 9 patients had stones located in the CBD, with 2 patients also having additional stones within the hepatic ducts. All 9 patients (100%) were visually stone-free after one endoscopic procedure. No major perioperative complications occurred. Mean length of stay was 2.4 days. At a mean radiological follow-up of 5.4 months (range, 0.5 to 21), no stone recurrence was noted. Conclusions: Percutaneous endoscopic holmium laser lithotripsy is a minimally invasive alternative to open salvage surgery for complex biliary calculi refractory to standard approaches. This treatment is both safe and efficacious. Success depends on a multidisciplinary approach. PMID:19660213

  16. Optimization of dosimetry and safety using the holmium laser for urology

    NASA Astrophysics Data System (ADS)

    van Swol, Christiaan F. P.; Verdaasdonck, Rudolf M.; Zeijlemaker, Bram Y. W.; Grimbergen, Matthijs C. M.; Boon, Tom A.

    1998-07-01

    The holmium laser has become accepted as a versatile instrument for urological applications, such as prostate resection, urethrotomy, tumor coagulation and lithotripsy. Presently, more powerful lasers have become available generating pulses up to 4 J at 80 W. The necessity of these high power systems in urology is ambiguous. In this study, the dosimetry as to efficacy and especially safety was investigated for various applications. The holmium laser ((lambda) equals 2.1 micrometer) emits its energy in 350 microsecond pulses which instantly turn water into vapor. Using high-speed photography explosive vapor bubbles with diameters over 10 mm were captured. The mechanical force of these bubbles, effectively fragments stones but may dilate and rupture a small lumen like the ureter. After implosion of the bubble, the energy of vaporization turns into heat. Depending on pulse energy and pulse repetition rate, tissue can be thermally affected up to 5 mm. For soft tissue applications, e.g., urethrotomy, prostatectomy or tumor coagulation, pulse energies of 0.5 - 1.5 J were applied at a high repetition rate (20 - 40 Hz) to provide sufficient coagulative and hemostatic effects. At higher pulse energies, the fiber tip was vibrating vigorously and the tissue was ripped to pieces decreasing hemostasis and visibility. For hard tissue applications, bursts of 0.5 J pulses at 5 Hz, proved to be sufficient to fragment all types of stones (including cystine) in the ureter and the bladder without mechanical or thermal damage to surrounding tissue. At higher settings, targeting the stone was less controlled and effective due to 'jumping' of the fiber tip with resulting mechanical and thermal trauma to the surrounding tissue. The holmium laser can be used effectively to coagulate and cut soft tissue and fragment stones at relatively low energy and power settings, thus minimizing the risk of complications.

  17. Amphoteric doping of praseodymium Pr{sup 3+} in SrTiO{sub 3} grain boundaries

    SciTech Connect

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-23

    Charge compensation in rare-earth Praseodymium (Pr{sup 3+}) doped SrTiO{sub 3} plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr{sup 3+} doping behavior in SrTiO{sub 3} grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy. The presence of Pr{sup 3+} induces structural variations and changes the statistical prevalence of the GB structures. In contrast to the assumption that Pr{sup 3+} substitutes on the Sr site in the bulk, Pr{sup 3+} is found to substitute on both Sr and Ti sites inside the GBs, with the highest concentration at the Ti sites. This amphoteric doping behavior in the boundary plane is further confirmed by first principles theoretical calculations.

  18. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    SciTech Connect

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-26

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. As a result, this amphoteric doping behavior in the boundary plane is further confirmed by first principles theoretical calculations.

  19. Non-destructive analysis of didymium and praseodymium molybdate crystals using energy dispersive X-ray fluorescence technique

    NASA Astrophysics Data System (ADS)

    Bhat, C. K.; Joseph, Daisy; Pandita, Sanjay; Kotru, P. N.

    2016-08-01

    Analysis of didymium (Di) and praseodymium molybdate crystals were carried out using energy dispersive X-ray fluorescence (EDXRF). The assigned empirical chemical formulae of the composites were tested and verified by the EDXRF technique by estimating experimental major elemental concentration ratios. On the Basis of these ratios, the established formulae for some of the composite materials have been verified and suggestions made for their refinement. Non-destructive technique used in this analysis enables to retain the original crystal samples and makes rapid simultaneous scan of major elements such as La, Pr, Ned and Mo as well as impurities such as Ce. Absence of samarium(Sm) in the spectrum during analysis of didymium molybdate crystals indicated an incomplete growth of mixed rare earth single crystal. These crystals (e.g.,Di) are shown to be of modified stoichiometry with Ce as trace impurity.

  20. Erbium ion implantation into different crystallographic cuts of lithium niobate

    NASA Astrophysics Data System (ADS)

    Nekvindova, P.; Svecova, B.; Cajzl, J.; Mackova, A.; Malinsky, P.; Oswald, J.; Kolistsch, A.; Spirkova, J.

    2012-02-01

    Single crystals like lithium niobate are frequently doped with optically active rare-earth or transition-metal ions for a variety of applications in optical devices such as solid-state lasers, amplifiers or sensors. To exploit the potential of the Er:LiNbO 3, one must ensure high intensity of the 1.5 μm luminescence as an inevitable prerequisite. One of the important factors influencing the luminescence properties of a lasing ion is the crystal field of the surrounding, which is inevitably determined by the crystal structure of the pertinent material. From that point it is clear that it cannot be easy to affect the resulting luminescence properties - intensity or position of the luminescence band - without changing the structure of the substrate. However, there is a possibility to utilise a potential of the ion implantation of the lasing ions, optionally accompanied with a sensitising one, that can, besides the doping, also modify the structure of the treated area od the crystal. This effect can be eventually enhanced by a post-implantation annealing that may help to recover the damaged structure and hence to improve the desired luminescence. In this paper we are going to report on our experiments with ion-implantation technique followed with subsequent annealing could be a useful way to influence the crystal field of LN. Optically active Er:LiNbO 3 layers were fabricated by medium energy implantation under various experimental conditions. The Er + ions were implanted at energies of 330 and 500 keV with fluences ranging from 1.0 × 10 15 to 1.0 × 10 16 ion cm -2 into LiNbO 3 single-crystal cuts of both common and special orientations. The as-implanted samples were annealed in air and oxygen at two different temperatures (350 and 600 °C) for 5 h. The depth concentration profiles of the implanted erbium were measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He + ions. The photoluminescence spectra of the samples were measured to determine the

  1. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization.

    PubMed

    Asimakopoulos, Anastasios D; Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication. PMID:27022498

  2. Holmium-lipiodol-alginate microspheres for fluoroscopy-guided embolotherapy and multimodality imaging.

    PubMed

    Oerlemans, Chris; Seevinck, Peter R; Smits, Maarten L; Hennink, Wim E; Bakker, Chris J G; van den Bosch, Maurice A A J; Nijsen, J Frank W

    2015-03-30

    Embolotherapy is a minimally invasive transcatheter technique aiming at reduction or complete obstruction of the blood flow by infusion of micro-sized particles in order to induce tumor regression. A major drawback of the current commercially available and clinically used microspheres is that they cannot be detected in vivo with medical imaging techniques, impeding intra- and post-procedural feedback. It can be expected that real-time monitoring of microsphere infusion and post-procedural imaging will result in better predictability and higher efficacy of the treatment. In this study, a novel microsphere formulation has been developed that can be visualized with fluoroscopy, X-ray computed tomography (CT) and magnetic resonance imaging (MRI). The microspheres were prepared with the JetCutter technique and consist of alginate (matrix-forming polymer), holmium (cross-linking and MRI contrast agent), lipiodol (radiopaque contrast agent) and Pluronic F-68 (surfactant). The mean size (±SEM) of the hydrated holmium-lipiodol-alginate microspheres (Ho-lip-ams) was 570±12 μm with a holmium content of 0.38±0.01% (w/w). Stability studies showed that the microspheres remained intact during incubation for two weeks in fetal calf serum (FCS) at 37 °C. The inclusion of lipiodol in the microspheres rendered excellent visualization capabilities for fluoroscopy and CT, whereas the holmium ions, which keep the alginate network together, also allow MR imaging. In this study it was shown that single sphere detection was possible by fluoroscopy, CT and MRI. The Ho-lip-ams were visualized in real-time, during infusion in a porcine kidney using fluoroscopy, and post-procedural, the deposition of the microspheres was examined with fluoroscopy, (cone beam rotational) CT and MRI. The different imaging modalities showed similar deposition patterns of the microspheres within the organ. The combination of intra-procedural visualization, multimodality imaging for patient follow-up and the

  3. Holmium Laser Enucleation of the Prostate and Iatrogenic Arteriovenous Fistula Treated by Superselective Arterial Embolization

    PubMed Central

    Dutto, Lorenzo; Preziosi, Paolo; Spera, Enrico; Micali, Francesco; De Carolis, Andrea; Iorio, Beniamino

    2016-01-01

    Iatrogenic pelvic pseudoaneurysm with concomitant arteriovenous fistula has been described as a rare and challenging complication, which may occur during transurethral resection of the prostate. We provide the first report of this complication after holmium laser enucleation of the prostate for the treatment of benign prostatic hyperplasia. The attempt to control the bleeding by conversion to open surgery and placement of haemostatic stitches into the prostatic fossa failed. Angiography with superselective arterial embolization proved to be a modern, quick, safe, and efficient treatment of this uncommon complication. PMID:27022498

  4. Endoscopic removal of a proximal urethral stent using a holmium laser: Case report and literature review

    PubMed Central

    Botelho, Francisco; Thomas, Anil A.; Miocinovic, Ranko; Angermeier, Kenneth W.

    2012-01-01

    Urethral stents were initially developed for the management of urethral strictures and obstructive voiding disorders in select patients. Urethral stent complications are common and may require stent explantation, which is often quite challenging. We present our experience with endoscopic removal of an encrusted UroLume proximal urethral stent in a 72-year-old male using a holmium laser. The literature on various management options and outcomes for urethral stent removal is reviewed. Endoscopic removal of proximal urethral stents is feasible and safe and should be considered as the primary treatment option in patients requiring stent extraction. PMID:23248530

  5. Technical Aspects of Holmium Laser Enucleation of the Prostate for Benign Prostatic Hyperplasia

    PubMed Central

    Kim, Myong; Lee, Hahn-Ey

    2013-01-01

    Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure and a size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. HoLEP has become an alternative to conventional transurethral resection of the prostate or open prostatectomy owing to its efficacy and safety. Although HoLEP is known to have a steep learning curve, very few articles have addressed the technical aspects of HoLEP. Herein, we described detailed techniques and tips for HoLEP as performed at Seoul National University Hospital in a step-by-step manner with extensive review of the literature. PMID:24044089

  6. Spectroscopic properties, energy transfer dynamics, and laser performance of thulium-holmium doped laser systems

    SciTech Connect

    Kalisky, Y.; Rotman, S.R.; Boulon, G.; Pedrini, C.; Brenier, A.

    1994-12-31

    Spectroscopic studies using laser induced fluorescence and numerical modeling of energy transfer and back transfer mechanism are reported in Er:Tm:Ho:YLF, Cr:Tm:Ho:YAG and Cr:Tm:YAG laser crystals at various temperatures (10 K-300 K). Direct energy transfer from Tm{sup 3+} excited states to Ho{sup 3+} {sup 5}I{sub 7} emitting level was observed and analyzed both in YAG and YLF. Further analysis of Cr{sup 3+} and Tm{sup 3+} time-dependent emission curves indicate a strong correlation of chromium-thulium pairs. Pulsed operation of holmium laser at high temperature will be presented.

  7. Holmium laser enucleation of the prostate: a paradigm shift in benign prostatic hyperplasia surgery

    PubMed Central

    2013-01-01

    Holmium laser enucleation (HoLEP) was developed in the 1990s as a more efficient and cost effective method of benign prostatic hyperplasia surgery than laser vaporization and resection techniques. As a true anatomical enucleation it mimics open prostatectomy and is as durable. There is a significant body of level 1 evidence in support of HoLEP, including 2 meta-analyses and 14 randomized trials which compare HoLEP with a number of other procedures. This review describes the development of and summarizes the evidence for HoLEP. PMID:24082919

  8. Technical aspects of holmium laser enucleation of the prostate for benign prostatic hyperplasia.

    PubMed

    Kim, Myong; Lee, Hahn-Ey; Oh, Seung-June

    2013-09-01

    Holmium laser enucleation of the prostate (HoLEP) is a minimally invasive procedure and a size-independent treatment for benign prostatic hyperplasia with excellent long-term surgical outcome. HoLEP has become an alternative to conventional transurethral resection of the prostate or open prostatectomy owing to its efficacy and safety. Although HoLEP is known to have a steep learning curve, very few articles have addressed the technical aspects of HoLEP. Herein, we described detailed techniques and tips for HoLEP as performed at Seoul National University Hospital in a step-by-step manner with extensive review of the literature. PMID:24044089

  9. Holmium laser enucleation of the prostate: a paradigm shift in benign prostatic hyperplasia surgery.

    PubMed

    Aho, Tevita F

    2013-10-01

    Holmium laser enucleation (HoLEP) was developed in the 1990s as a more efficient and cost effective method of benign prostatic hyperplasia surgery than laser vaporization and resection techniques. As a true anatomical enucleation it mimics open prostatectomy and is as durable. There is a significant body of level 1 evidence in support of HoLEP, including 2 meta-analyses and 14 randomized trials which compare HoLEP with a number of other procedures. This review describes the development of and summarizes the evidence for HoLEP. PMID:24082919

  10. Raman and Fluorescence Study of Erbium-Doped Laser-Induced Crystals-in-Glass

    NASA Astrophysics Data System (ADS)

    Knorr, Brian; Veenhuizen, Keith; Stone, Adam; Jain, Himanshu; Dierolf, Volkmar

    Laser induced crystallization of glasses is a spatially selective process which has the potential to produce photonic integrated circuits in a glass matrix. Low temperature Combined Excitation Emission Spectroscopy in Er:LaBGeO5 show that erbium incorporates at predominantly one majority site in both glass-ceramics and laser-induced crystals-in-glass, but that other minority sites also exist. The energy levels of the majority site were quantified. The fluorescence characteristics of the erbium ions in any site in the laser-induced crystals were found to be only weakly influenced by the irradiation conditions during growth. On the other hand, a hidden parameter, potentially boron deficiency-related defects, resulted in a significant change in the incorporation behavior of the erbium ions. Simultaneous scanning confocal Raman and fluorescence spectroscopy showed that the energies of the Raman modes are shifted, and the erbium fluorescence intensity varies, in a non-uniform manner, despite the host glass being homogeneously doped, across the cross-sections of laser-induced crystals in glass. These fluctuations within the Raman and fluorescence are spatially correlated, implying that different erbium sites form preferentially at different locations in the crystal cross-section.

  11. Root Surface Bio-modification with Erbium Lasers- A Myth or a Reality??

    PubMed Central

    Lavu, Vamsi; Sundaram, Subramoniam; Sabarish, Ram; Rao, Suresh Ranga

    2015-01-01

    The objective of this literature review was to critically review the evidence available in the literature regarding the expediency of erbium family of lasers for root bio modification as a part of periodontal therapy. The literature search was performed on the Pubmed using MeSH words such as "lasers/therapeutic use, scaling, dental calculus, tooth root/anatomy and histology, ultrasonic therapy". The studies were screened and were grouped as follows: those evaluating a) efficacy for calculus removal with the Erbium family of laser b) root surface changes following Er YAG and Er Cr YSGG application c) comparative studies of the Er YAG, Er Cr YSGG lasers versus conventional methods of root surface modification d) Bio compatibility of root surface following Erbium laser treatment e) Studies on the combined efficacy of laser root modification with conventional methods towards root surface bio-modification f) Studies on effectiveness of root surface bio-modification prior to root coverage procedures. In conclusion, the erbium family has a proven anti-bacterial action, predictable calculus removal, minimal root substance removal, and appears to favor cell attachment. The Erbium family of lasers appears to be a useful adjunct for the management of periodontal disease. PMID:25713635

  12. Surface behaviour in deuterium permeation through erbium oxide coatings

    NASA Astrophysics Data System (ADS)

    Chikada, T.; Suzuki, A.; Adelhelm, C.; Terai, T.; Muroga, T.

    2011-06-01

    Suppression of tritium permeation through structural materials is essential in order to mitigate fuel loss and radioactivity concerns. Ceramic coatings have been investigated for over three decades as tritium permeation barriers (TPBs); however, a very limited number of investigations on the mechanism of hydrogen-isotope permeation through the coatings have been reported. In this study, deuterium permeation behaviour of erbium oxide coatings fabricated by filtered arc deposition on reduced activation ferritic/martensitic steels has been investigated. The samples coated on both sides of the substrates showed remarkably lower permeability than those coated on one side, and the maximum reduction efficiency indicated a factor of 105 compared with the substrate. The different permeation behaviour between the coatings facing the high and low deuterium pressure sides has been found by the crystal structure analysis and the evaluation of the energy barriers. It is suggested that the permeation processes on the front and back surfaces are independent, and the TPB efficiency of the samples coated on both sides can be expressed by a multiplication of that of each side.

  13. Hydrogen diffusion along grain boundaries in erbium oxide coatings

    NASA Astrophysics Data System (ADS)

    Mao, Wei; Chikada, Takumi; Suzuki, Akihiro; Terai, Takayuki

    2014-12-01

    Diffusion of interstitial atomic hydrogen in erbium oxide (Er2O3) was investigated using density functional theory (DFT) and molecular dynamics (MD) methods. Hydrogen diffusivity in bulk, on (0 0 1) surface, and along Σ13 (4-3-1)/[1 1 1] symmetric tilt grain boundaries (GBs) were evaluated in a temperature range of 673-1073 K, as well as hydrogen diffusion barriers. It was found that H diffusion shows the faster on (0 0 1) surface than along GBs and in bulk. Also, energy barrier of H diffusion in bulk estimated by DFT and MD methods is somewhat higher than that along GBs evaluated in the experiments. This suggests that H diffusion in Er2O3 coatings depends on GBs rather than bulk. In addition, with a correction of GB density, the simulated diffusivity along GBs in MD simulations is in good agreement with the experimental data within one order of magnitude. The discrepancy of H diffusivity between the experiments and the simulations should be reduced by considering H concentration, H diffusion direction, deviations of the initial configuration, vacancy defects, etc.

  14. Cavitation bubbles induced by Erbium lasers: implications for dentistry

    NASA Astrophysics Data System (ADS)

    Verleng, Marja; Verdaasdonk, Rudolf; van der Veen, Albert; Lemberg, Vladimir; Boutoussov, Dmitri

    2014-02-01

    With new fiber systems available for 3 μm, Erbium lasers become more interesting for precise tissue ablation in a water environment enabling new application in e.g. dentistry. The dynamics of explosive bubble formation was investigated at 2.78 μm (Er,Cr;YSGG) and 2.94 μm (Er:YAG), in relation to energy (10-50 mJ), pulse length (20-150 μs) and fiber tip shape (flat or taper). The dynamics of exploding and imploding vapor bubbles were captured with high speed imaging (10 - 300 μs range). Increasing the pulse length and energy, the vapor bubble became more elongated with an opaque surface for flat tip fibers. Tapered fibers produced spherical vapor bubbles with an optically transparent surface expected to be more forceful for creating mechanical effects in both hard and soft tissues. There was no significant difference between bubbles formed at 2.78 μm (Er,Cr;YSGG) and 2.94 μm (Er:YAG).

  15. Advanced experiments with an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Marques, Paulo V. S.; Marques, Manuel B.; Rosa, Carla C.

    2014-07-01

    This communication describes an optical hands-on fiber laser experiment aimed at advanced college courses. Optical amplifiers and laser sources represent very important optical devices in numerous applications ranging from telecommunications to medicine. The study of advanced photonics experiments is particularly relevant at undergraduate and master level. This paper discusses the implementation of an optical fiber laser made with a cavity built with two tunable Bragg gratings. This scheme allows the students to understand the laser working principles as a function of the laser cavity set-up. One or both of the gratings can be finely tuned in wavelength through applied stress; therefore, the degree of spectral mismatch of the two gratings can be adjusted, effectively changing the cavity feedback. The impact of the cavity conditions on the laser threshold, spectrum and efficiency is analyzed. This experiment assumes that in a previous practice, the students should had already characterized the erbium doped fiber in terms of absorption and fluorescent spectra, and the spectral gain as a function of pump power.

  16. Ablation characteristics of quantum square pulse mode dental erbium laser

    NASA Astrophysics Data System (ADS)

    Lukač, Nejc; Suhovršnik, Tomaž; Lukač, Matjaž; Jezeršek, Matija

    2016-01-01

    Erbium lasers are by now an accepted tool for performing ablative medical procedures, especially when minimal invasiveness is desired. Ideally, a minimally invasive laser cutting procedure should be fast and precise, and with minimal pain and thermal side effects. All these characteristics are significantly influenced by laser pulse duration, albeit not in the same manner. For example, high cutting efficacy and low heat deposition are characteristics of short pulses, while vibrations and ejected debris screening are less pronounced at longer pulse durations. We report on a study of ablation characteristics on dental enamel and cementum, of a chopped-pulse Er:YAG [quantum square pulse (QSP)] mode, which was designed to reduce debris screening during an ablation process. It is shown that in comparison to other studied standard Er:YAG and Er,Cr:YSGG laser pulse duration modes, the QSP mode exhibits the highest ablation drilling efficacy with lowest heat deposition and reduced vibrations, demonstrating that debris screening has a considerable influence on the ablation process. By measuring single-pulse ablation depths, we also show that tissue desiccation during the consecutive delivery of laser pulses leads to a significant reduction of the intrinsic ablation efficacy that cannot be fully restored under clinical settings by rehydrating the tooth using an external water spray.

  17. Electroluminescence efficiencies of erbium in silicon-based hosts

    SciTech Connect

    Cueff, Sébastien E-mail: christophe.labbe@ensicaen.fr; Manel Ramírez, Joan; Berencén, Yonder; Garrido, Blas; Kurvits, Jonathan A.; Zia, Rashid; Rizk, Richard; Labbé, Christophe E-mail: christophe.labbe@ensicaen.fr

    2013-11-04

    We report on room-temperature 1.5 μm electroluminescence from trivalent erbium (Er{sup 3+}) ions embedded in three different CMOS-compatible silicon-based hosts: SiO{sub 2}, Si{sub 3}N{sub 4}, and SiN{sub x}. We show that although the insertion of either nitrogen or excess silicon helps enhance electrical conduction and reduce the onset voltage for electroluminescence, it drastically decreases the external quantum efficiency of Er{sup 3+} ions from 2% in SiO{sub 2} to 0.001% and 0.0004% in SiN{sub x} and Si{sub 3}N{sub 4}, respectively. Furthermore, we present strong evidence that hot carrier injection is significantly more efficient than defect-assisted conduction for the electrical excitation of Er{sup 3+} ions. These results suggest strategies to optimize the engineering of on-chip electrically excited silicon-based nanophotonic light sources.

  18. Refractive index of erbium doped GaN thin films

    SciTech Connect

    Alajlouni, S.; Sun, Z. Y.; Li, J.; Lin, J. Y.; Jiang, H. X.; Zavada, J. M.

    2014-08-25

    GaN is an excellent host for erbium (Er) to provide optical emission in the technologically important as well as eye-safe 1540 nm wavelength window. Er doped GaN (GaN:Er) epilayers were synthesized on c-plane sapphire substrates using metal organic chemical vapor deposition. By employing a pulsed growth scheme, the crystalline quality of GaN:Er epilayers was significantly improved over those obtained by conventional growth method of continuous flow of reaction precursors. X-ray diffraction rocking curve linewidths of less than 300 arc sec were achieved for the GaN (0002) diffraction peak, which is comparable to the typical results of undoped high quality GaN epilayers and represents a major improvement over previously reported results for GaN:Er. Spectroscopic ellipsometry was used to determine the refractive index of the GaN:Er epilayers in the 1540 nm wavelength window and a linear dependence on Er concentration was found. The observed refractive index increase with Er incorporation and the improved crystalline quality of the GaN:Er epilayers indicate that low loss GaN:Er optical waveguiding structures are feasible.

  19. Assignments of the Raman modes of monoclinic erbium oxide

    SciTech Connect

    Yan, D.; Wu, P. Zhang, S. P.; Liang, L.; Yang, F.; Pei, Y. L.; Chen, S.

    2013-11-21

    As a heavy rare earth oxide, erbium oxide (Er{sub 2}O{sub 3}) has many attractive properties. Monoclinic Er{sub 2}O{sub 3} has useful properties not found in stable cubic Er{sub 2}O{sub 3}, such as unique optical properties and high radiation damage tolerance. In this study, cubic Er{sub 2}O{sub 3} coating and Er{sub 2}O{sub 3} coating with mixed phases were prepared. The Raman scattering spectra of these coatings were investigated by using a confocal micro-Raman spectrometer equipped with 325, 473, 514, 532, 633, and 784 nm lasers. A total of 17 first-order Raman modes of monoclinic Er{sub 2}O{sub 3} were identified and assigned. The modes at 83, 112, 152, 170, 278, 290, 409, 446, 478, 521, 603, and 622 cm{sup −1} are of A{sub g} symmetry, whereas modes at 71, 98, 333, 409, 446, and 468 cm{sup −1} are of B{sub g} symmetry. This research provides basic data necessary for the characterization of monoclinic Er{sub 2}O{sub 3} by Raman spectroscopy.

  20. Evaluation of holmium laser versus cold knife in optical internal urethrotomy for the management of short segment urethral stricture

    PubMed Central

    Jain, Sudhir Kumar; Kaza, Ram Chandra Murthy; Singh, Bipin Kumar

    2014-01-01

    Objectives: Sachse cold knife is conventionally used for optical internal urethrotomy intended to manage urethral strictures and Ho: YAG laser is an alternative to it. The aim of this study was to evaluate the role of urethral stricture treatment outcomes, efficacy, and complications using cold knife and Ho: YAG (Holmium laser) for optical internal urethrotomy Materials and Methods: In this prospective study included, 90 male patients age >18 years, with diagnosis of urethral stricture admitted for internal optical urethrotomy during April 2010 to March 2012. The patients were randomized into two groups containing 45 patients each using computer generated random number. In group A (Holmium group), internal urethrotomy was done with Holmium laser and in group B (Cold knife group) Sachse cold knife was used. Patients were followed up for 6 months after surgery in Out Patient Department on 15, 30 and 180 post-operative days. At each follow up visit physical examination, and uroflowmetry was performed along with noting complaints, if any. Results: The peak flow rates (PFR) were compared between the two groups on each follow up. At 180 days (6 month interval) the difference between mean of PFR for Holmium and Cold knife group was statistically highly significant (P < 0.001). Complications were seen in 12.22% of cases. Conclusion: Both modalities are effective in providing immediate relief to patients with single and short segment (<2 cm long) urethral strictures but more sustained response was attained with Cold knife urethrotomy. PMID:25371611

  1. The study on the effect of erbium on diamond-like carbon deposited by pulsed laser deposition technique

    NASA Astrophysics Data System (ADS)

    Foong, Y. M.; Hsieh, J.; Li, X.; Chua, D. H. C.

    2009-09-01

    Diamond-like carbon (DLC) films doped with a small fraction of erbium (0.5-2.0 at. %, at 0.5 at. % interval) were prepared by using a 248 nm KrF pulsed laser deposition technique. The effects of erbium on the surface morphology, microstructure, chemical binding states, tribological property, and the adhesion strength of DLC films were investigated. Atomic force microscopy showed that the surface roughness of the films increased with the increasing of erbium fraction, but generally the nanocomposite films were smooth with rms below 1 nm. Raman analysis showed broad peaks centered at 1550 cm-1 on all the samples. The deconvoluted Raman spectra on DLC doped with different fractions of erbium showed that the ID/IG ratio increased with increasing erbium content, and the comparative percent of sp3 is between 50% and 58% for erbium fraction between 0.5 and 2.0 at. %. High resolution x-ray photoelectron spectroscopy confirmed that the C 1s peaks had slightly shifted away from 285.2 (diamond) to 284.5 eV (graphite). The deconvolution of the spectra further confirmed the influence of erbium to the sp3 contents and revealed the presence of SiC with the increasing of Er fraction. Microscratch tester results showed that the adhesion strength (critical load) of the films improved with the presence of SiC bonding at the interface. This hinted that the presence of the heavier erbium may force the impinging carbon ions to react more with the interface to form silicon carbide bonds, thus enhancing the adhesion strength. Although the presence of erbium increased the surface roughness of the films, the coefficients of friction of the erbium doped DLC films were still closely resembled to pure DLC, i.e., 0.11-0.12 compared to 0.10 for pure DLC.

  2. Optical characterization and crystal field calculations for some erbium based solid state materials for laser refrigeration

    NASA Astrophysics Data System (ADS)

    Hasan, Z.; Qiu, Z.; Johnson, Jackie; Homerick, Uwe

    2009-02-01

    The potential of three erbium based solids hosts has been investigated for laser cooling. Absorption and emission spectra have been studied for the low lying IR transitions of erbium that are relevant to recent reports of cooling using the 4I15/2-4I9/2 and4I15/2 -4I13/2 transitions. Experimental studies have been performed for erbium in three hosts; ZBLAN glass and KPb2Cl5 and Cs2NaYCl6 crystals. In order to estimate the efficiencies of cooling, theoretical calculations have been performed for the cubic Elpasolite (Cs2NaYCl6 ) crystal. These calculations also provide a first principle insight into the cooling efficiency for non-cubic and glassy hosts where such calculations are not possible.

  3. Enhancement of photoluminescence intensity of erbium doped silica containing Ge nanocrystals: distance dependent interactions

    NASA Astrophysics Data System (ADS)

    Manna, S.; Aluguri, R.; Bar, R.; Das, S.; Prtljaga, N.; Pavesi, L.; Ray, S. K.

    2015-01-01

    Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol-gel method are presented in this article. Strong photoluminescence at 1.54 μm, important for fiber optics telecommunication systems, is observed from the different sol-gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er3+ ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established.

  4. Low-temperature growth of silicon epitaxial layers codoped with erbium and oxygen atoms

    SciTech Connect

    Shengurov, D. V.; Chalkov, V. Yu.; Denisov, S. A.; Shengurov, V. G.; Stepikhova, M. V.; Drozdov, M. N.; Krasilnik, Z. F.

    2013-03-15

    The fabrication technology and properties of light-emitting Si structures codoped with erbium and oxygen are reported. The layers are deposited onto (100) Si by molecular beam epitaxy (MBE) using an Er-doped silicon sublimation source. The partial pressure of the oxygen-containing gases in the growth chamber of the MBE facility before layer growth is lower than 5 Multiplication-Sign 10{sup -10} Torr. The oxygen and erbium concentrations in the Si layers grown at 450 Degree-Sign C is {approx}1 Multiplication-Sign 10{sup 19} and 10{sup 18} cm{sup -3}, respectively. The silicon epitaxial layers codoped with erbium and oxygen have high crystal quality and yield effective photoluminescence and electroluminescence signals with the dominant optically active Er-1 center forming upon postgrowth annealing at a temperature of 800 Degree-Sign C.

  5. In vitro application of optical transmission systems in erbium:YAG laser temporomandibular joint surgery

    NASA Astrophysics Data System (ADS)

    Nuebler-Moritz, Michael; Hering, Peter; Niederdellmann, Herbert; Deuerling, Christian; Dammer, Ralf

    1995-05-01

    The experimental setup of this study is focused on the changes in temporomandibular joint tissue after irradiation with an Erbium:YAG laser. Initially, the free-running beam from the laser was focused onto freshly excised porcine tissue samples, indicating an optimum average energy density and pulse duration for the purpose of temporomandibular joint surgery of about 15 - 60 J/cm2 and 120 microsecond(s) - 240 microsecond(s) , respectively. Consecutively, an attempt was made to couple the Erbium:YAG laser beam on the one hand to optical fibers made of infrared-transmitting glasses (fluoride- and chalcogenide-based), on the other hand to a recently developed sapphire and liquid core fiber, respectively. From the preliminary observations of this investigation it appears that both the liquid core and the sapphire fiber are the most promising candidates for delivery of Erbium-YAG laser radiation in arthroscopic surgery of the craniomandibular articulation.

  6. Synthesis and characterization of discrete luminescent erbium-doped silicon nanocrystals

    SciTech Connect

    John, J.S.; Coffer, J.L.; Chen, Y.; Pinizzotto, R.F.

    1999-03-10

    The preparation of discrete erbium-doped silicon nanoparticles prepared by the co-pyrolysis of disilane and the volatile complex Er(tmhd){sub 3} (tmhd = 2,2,6,6-tetramethyl-3,5-heptanedionato) is described. The nanoparticles were characterized by transmission electron microscopy, selected area electron diffraction, X-ray dispersive spectroscopy, photoluminescence, and UV-visible absorption spectroscopies. Erbium-doped silicon nanoparticles possess a distinctive dark contrast in the transmission electron microscope, and the presence of erbium is confirmed by X-ray energy dispersive spectroscopy. The mean diameter of the nanoparticle aggregates can be shifted by altering the length of the pyrolysis oven employed. Characteristic Er{sup 3+} near-infrared photoluminescence at 1,540 nm is detected in these doped nanoparticles; preliminary excitation and power dependence measurements of this luminescence suggest a carrier-mediated emission mechanism.

  7. Photoluminescence in silicon implanted with erbium ions at an elevated temperature

    SciTech Connect

    Sobolev, N. A. Kalyadin, A. E.; Shek, E. I.; Sakharov, V. I.; Serenkov, I. T.; Vdovin, V. I.; Parshin, E. O.; Makoviichuk, M. I.

    2011-08-15

    Photoluminescence spectra of n-type silicon upon implantation with erbium ions at 600 Degree-Sign C and oxygen ions at room temperature and subsequent annealings at 1100 Degree-Sign C in a chlorine-containing atmosphere have been studied. Depending on the annealing duration, photoluminescence spectra at 80 K are dominated by lines of the Er{sup 3+} ion or dislocation-related luminescence. The short-wavelength shift of the dislocation-related luminescence line observed at this temperature is due to implantation of erbium ions at an elevated temperature. At room temperature, lines of erbium and dislocation-related luminescence are observed in the spectra, but lines of near-band-edge luminescence predominate.

  8. Enhancement of photoluminescence intensity of erbium doped silica containing Ge nanocrystals: distance dependent interactions.

    PubMed

    Manna, S; Aluguri, R; Bar, R; Das, S; Prtljaga, N; Pavesi, L; Ray, S K

    2015-01-30

    Photo-physical processes in Er-doped silica glass matrix containing Ge nanocrystals prepared by the sol-gel method are presented in this article. Strong photoluminescence at 1.54 μm, important for fiber optics telecommunication systems, is observed from the different sol-gel derived glasses at room temperature. We demonstrate that Ge nanocrystals act as strong sensitizers for Er(3+) ions emission and the effective Er excitation cross section increases by almost four orders of magnitude with respect to the one without Ge nanocrystals. Rate equations are considered to demonstrate the sensitization of erbium luminescence by Ge nanocrystals. Analyzing the erbium effective excitation cross section, extracted from the flux dependent rise and decay times, a Dexter type of short range energy transfer from a Ge nanocrystal to erbium ion is established. PMID:25558802

  9. Photoluminescence in semiconductor structures based on butyl-substituted erbium phthalocyanine complexes

    SciTech Connect

    Belogorokhov, I. A. Ryabchikov, Yu. V.; Tikhonov, E. V.; Pushkarev, V. E.; Breusova, M. O.; Tomilova, L. G.; Khokhlov, D. R.

    2008-03-15

    The study is concerned with the luminescence properties of ensembles of semiconductor structures containing organic phthalocyanine molecules with erbium ions as complexing agents. The photoluminescence spectra of the structures of the type of erbium monophthalocyanine, bisphthalocyanine, and triphthalocyanine are recorded. The photoluminescence peaks are detected at the wavelengths 888, 760, and 708 nm (and photon energies 1.4, 1.6, and 1.75 eV) corresponding to electronic transitions within the organic complexes. It is found that, when a metal complexing agent is introduced into the molecular structure of the ligand, the 708 nm luminescence peak becomes unobservable. It is shown that, in the bisphthalocyanine samples, the photoluminescence signal corresponding to transitions from the 4F{sub 9/2} level of erbium ions is enhanced.

  10. Treatment of Parapelvic Cyst by Internal Drainage Technology Using Ureteroscope and Holmium Laser

    PubMed Central

    Zhao, Q; Huang, S; Li, Q; Xu, L; Wei, X; Huang, S; Li, S; Liu, Z

    2015-01-01

    ABSTRACT Background: The aim of parapelvic cyst treatment is to have complete drainage of cyst fluid and prevent its further compression of the kidney and collective system. This study explores the efficacy and safety of surgical approaches with holmium laser ureteroscopic internal drainage in the treatment of parapelvic cyst. Methods: The compression effect of parapelvic cyst on the renal collective system was observed by rigid ureteroscope using retrograde ureteroscopic technology. With direct vision, the cyst wall on the obvious parapelvic compression site was cut. The diameter of the cyst wall cut was about 1 cm. The internal drainage was obtained by double-J tubes. When the cyst was in the inferior pole of kidney or where the rigid ureteroscope could not reach, a flexible ureteroscope was used. Results: In 28 cases of operation, 27 cases were successful. The cyst treatment time was eight to 40 minutes (average 26 minutes). During the operation, no massive haemorrhage, damage of nearby organ and ureter, or other complications happened. Time of follow-up was 10–72 months (average 39 months). The results of follow-up showed that in 22 cases, the cyst disappeared; the diameter of the cyst in four cases was reduced by more than half, and one case recurred. Conclusion: The treatment of parapelvic cyst by internal drainage operation using holmium laser and ureteroscopy was effective. The operation was safe with few complications. PMID:26426175

  11. Posterior Urethral Polyp: First Holmium-YAG Laser Ablation on a 3-Month-Old Infant

    PubMed Central

    Keskin, Ercument; Yapanoglu, Turgut; Adanur, Senol; Ziypak, Tevfik; Altay, Mehmet Sefa; Aksoy, Yılmaz

    2016-01-01

    Abstract Background: Urethral polyps are rare benign pathologies seen in the male posterior urethra, more frequently originating from verumontanum. In this article, we aimed to discuss diagnosis and treatment of a urethral polyp causing hematuria and urinary infection in a 3-month-old male infant. This is the first case in the literature in which a urethral polyp is treated with Holmium yttrium-aluminum-garnet (YAG) laser. Case Presentation: The patient was a 3-month-old male infant, and complains were hematuria and crying during micturition. Ultrasonography and voiding cystourethrogram were used for diagnosis. Urethral polyp was observed on urethrocystoscopy. Ablation was performed with a newborn cystoscope. Conclusion: Urethral polyp can cause hematuria and urinary obstruction and should be considered in the differential diagnosis of pathologies such as posterior urethral valve and cecoureterocele that could cause infravesical obstruction. Holmium-YAG laser is a good choice of treatment with easy application possibilities using a newborn cystoscope, especially for newborns and infants who have thin urethra. PMID:27579428

  12. Crystal structure of new complexes of praseodymium(III) nitrate and ytterbium(III) nitrate with 2,2': 6,2''-terpyridine

    SciTech Connect

    Charushnikova, I. A. Auwer, C. Den

    2006-12-15

    The crystal structure of new complexes of praseodymium(III) and ytterbium(III) (elements from the initial and final parts of the lanthanide series), namely, [Pr(NO{sub 3}){sub 3} (Terpy)((CH{sub 3}){sub 2}CO)] (I) and [Yb(NO{sub 3}){sub 2}(Terpy)(H{sub 2}O){sub 2}]NO{sub 3} . 2H{sub 2}O (II), is investigated. The structure of compound I consists of [Pr(NO{sub 3}){sub 3}(Terpy)((CH{sub 3}){sub 2}CO)] neutral complexes. The coordination number of the praseodymium atom is 10. The coordination polyhedron of the praseodymium atom can be described as a distorted bicapped tetragonal antiprism. The structure of compound II is composed of [Yb(NO{sub 3}){sub 2}(Terpy)(H{sub 2}O){sub 2}]{sup +} cationic complexes, nitrate anions, and molecules of crystallization water. The structural components are joined together via a three-dimensional system of hydrogen bonds. The coordination polyhedron of the ytterbium atom can be represented as a distorted tricapped trigonal prism. The coordination number of the ytterbium atom is 9.

  13. Nanostructuring an erbium local environment inside sol-gel silica glasses: toward efficient erbium optical fiber lasers

    NASA Astrophysics Data System (ADS)

    Savelii, Inna; El Hamzaoui, Hicham; Bigot, Laurent; Bouwmans, Géraud; Fsaifes, Ihsan; Capoen, Bruno; Bouazaoui, Mohamed

    2016-02-01

    To extend the use of erbium- (Er-)/aluminum- (Al-) codoped optical fibers in hostile environments, the reduction of the Al amount has been identified as a serious way to harden them against harsh radiation. In this work, sol-gel monolithic Er3+-doped and Er3+/Al3+-codoped silica glasses were prepared from nanoporous silica xerogels soaked in a solution containing an Er salt together or not with an Al salt. After sintering, these glasses were used as the core material of microstructured optical fibers made by the stack-and-draw method. The influence of Al incorporation on the optical properties of Er3+-doped silica glasses and fibers is investigated. This approach enabled the preparation of silica glasses containing dispersed Er3+ ions with low Al content. The obtained fibers have been tested in an all-fibered cavity laser architecture. The Er3+/Al3+-codoped fiber laser presents a maximum efficiency of 27% at 1530 nm. We show that without Al doping, the laser exhibits lower performances that depend on Er content inside the doped fiber core. The effect of Er pair-induced quenching also has been investigated through nonsaturable absorption experiments, which clearly indicate that the fraction of Er ion pairs is significantly reduced in the Al-codoped fiber.

  14. Manufacture and properties of erythromycin beads containing neutron-activated erbium-171

    SciTech Connect

    Parr, A.F.; Digenis, G.A.; Sandefer, E.P.; Ghebre-Sellassie, I.; Iyer, U.; Nesbitt, R.U.; Scheinthal, B.M. )

    1990-03-01

    To evaluate the effects of a neutron activation radiolabeling technique on an enteric-coated multiparticulate formulation of erythromycin, test quantities were produced under industrial pilot scale conditions. The pellets contained the stable isotope erbium oxide (Er-170), which was later converted by neutron activation into the short-lived gamma ray-emitting radionuclide, erbium-171. In vitro studies indicated that the dissolution profile, acid resistance, and enteric-coated surface of the pellets were minimally affected by the irradiation procedure. Antimicrobial potency was also unaffected, as determined by microbiological assay. Neutron activation thus appears to simplify the radiolabeling of complex pharmaceutical dosage forms for in vivo study by external gamma scintigraphy.

  15. Optical bistability in erbium-doped yttrium aluminum garnet crystal combined with a laser diode.

    PubMed

    Maeda, Y

    1994-01-10

    Optical bistability was observed in a simple structure of an injection laser diode combined with an erbium-doped yttrium aluminum garnet crystal. Since a hysteresis characteristic exists in the relationship between the wavelength and the injection current of a laser diode, an optical memory function capable of holding the output status is confirmed. In addition, an optical signal inversion was caused by the decrease of transmission of the erbium-doped yttrium aluminum garnet crystal against the red shift (principally mode hopping) of the laser diode. It is suggested that the switching time of this phenomenon is the time necessary for a mode hopping by current injection. PMID:20862016

  16. Erbium-doped sol-gel materials for optical applications

    NASA Astrophysics Data System (ADS)

    Berni, Anette; Mennig, Martin; Schmidt, Helmut K.

    2003-04-01

    A new chemical nanotechnological route for the preparation of fully densified doped SiO2 coatings with thicknesses in the low ´m-range on Si- and SiO2-wafers has been developed. Beside pure SiO2 coatings, that might be useful as a buffer layer on silicon, silicate layers with increased refractive index are needed for planar waveguide application. Therefore, a synthesis for the preparation of nano particulate sols was developed, thus allowing the incorporation of dopands like Al2O3, PbO and Er2O3 for passive and active layers. Alumina was incorporated for the improvement of the Erbium solubility in active components. The coating sols consist of an organic binder, dissolved in a suspension of nanoscaled silica particles (10 nm in diameter) and dopands and were applied on Si- and SiO2-wafers by spin coating. After removal of the binder at 500 °C, investigated by IR-spectroscopy, highly porous (nD = 1.23) but transparent doped silica layers were obtained. The densification of the layers was examined by measuring the refractive index by ellipsometry as a function of the densification temperature. Completely densified layers with thicknesses between 1.7 ´m (doped SiO2) and 6.5 ´m (doped SiO2) were obtained at temperatures between 1000 °C (doped SiO2) and 1100 °C) (pure SiO2). The layer thickness and unevenness was determined by interferometric measurements. The optical loss of Al2O3 and PbO doped layers was measured by prism coupling, the Er2O3 doped layers with Er3+ concentrations of up to 2.5 mole % show fluorescence around 1500 nm with a fluorescence lifetime of about 3.6 ms.

  17. Optical addressing of an individual erbium ion in silicon.

    PubMed

    Yin, Chunming; Rancic, Milos; de Boo, Gabriele G; Stavrias, Nikolas; McCallum, Jeffrey C; Sellars, Matthew J; Rogge, Sven

    2013-05-01

    The detection of electron spins associated with single defects in solids is a critical operation for a range of quantum information and measurement applications under development. So far, it has been accomplished for only two defect centres in crystalline solids: phosphorus dopants in silicon, for which electrical read-out based on a single-electron transistor is used, and nitrogen-vacancy centres in diamond, for which optical read-out is used. A spin read-out fidelity of about 90 per cent has been demonstrated with both electrical read-out and optical read-out; however, the thermal limitations of the former and the poor photon collection efficiency of the latter make it difficult to achieve the higher fidelities required for quantum information applications. Here we demonstrate a hybrid approach in which optical excitation is used to change the charge state (conditional on its spin state) of an erbium defect centre in a silicon-based single-electron transistor, and this change is then detected electrically. The high spectral resolution of the optical frequency-addressing step overcomes the thermal broadening limitation of the previous electrical read-out scheme, and the charge-sensing step avoids the difficulties of efficient photon collection. This approach could lead to new architectures for quantum information processing devices and could drastically increase the range of defect centres that can be exploited. Furthermore, the efficient electrical detection of the optical excitation of single sites in silicon represents a significant step towards developing interconnects between optical-based quantum computing and silicon technologies. PMID:23636400

  18. Nuclear Magnetic Resonance and High-Temperature Superconductivity in YTTRIUM(1-X)PRASEODYMIUM(X)BARIUM Cuprate

    NASA Astrophysics Data System (ADS)

    Reyes, Arneil Payongayong

    Copper nuclear magnetic resonance (NMR) has been performed on praseodymium-doped YBa_2Cu _3O_7, to investigate the nature of the depression of the superconducting transition temperature T_{c} with Pr concentration in this series and to provide insight into the microscopic and magnetic properties of high T_{c } planar cuprate materials. Praseodymium is unique among rare-earth dopants in suppressing superconductivity in the high T _{c} cuprate YBa _2Cu_3O_7 while maintaining the orthorhombic structure of the host. Temperature dependence of the Knight shift K and the nuclear relaxation rate 1/T_1 has been observed in Y-rich Y_{1-x}Pr _ xBa_2Cu _3O_7. Its striking resemblance to the behavior found in oxygen deficient YBa_2Cu_3O _{7-y} provides evidence that T_{c} depression in the former is primarily due to the removal of hole carriers as a consequence of Pr being close to tetravalent state. This hole-filling mechanism is consistent with the observed antiferromagnetic ordering of Cu spins on the plane sites in both PrBa_2Cu_3O_7 and YBa_2Cu_3O_6 since the absence of the doped-holes on the Cu -O_2 planes enhances spin correlations among Cu local moments. On the other hand, extensive analysis of the spin susceptibility has shown a tendency towards trivalency of Pr in specimens with low x values, suggesting that in the dilute limit pair-breaking due to conduction band-4f hybridization is also involved in the depression of T_{c}. The mixed-valent nature of Pr must therefore be considered for any adequate explanation of the suppression of superconductivity in Y_{1-x}Pr_ xBa_2Cu_3 O_7. The phenomenological model of antiferromagnetic Fermi liquid (AFL) proposed by Millis, Monien and Pines has been used to explain the behavior of the planar ^{63}Cu relaxation rate and to extract information on the strength of correlations among the local spins. Analysis has shown that the unusual behavior of the relaxation rate is a consequence of a competition between the temperature

  19. Growth studies of erbium-doped GaAs deposited by metalorganic vapor phase epitaxy using noval cyclopentadienyl-based erbium sources

    NASA Technical Reports Server (NTRS)

    Redwing, J. M.; Kuech, T. F.; Gordon, D. C.; Vaartstra, B. A.; Lau, S. S.

    1994-01-01

    Erbium-doped GaAS layers were grown by metalorganic vapor phase epitaxy using two new sources, bis(i-propylcyclopentadienyl)cyclopentadienyl erbium and tris(t-butylcyclopentadienyl) erbium. Controlled Er doping in the range of 10(exp 17) - 10(exp 18)/cu cm was achieved using a relatively low source temperature of 90 C. The doping exhibits a second-order dependence on inlet source partial pressure, similar to behavior obtained with cyclopentadienyl Mg dopant sources. Equivalent amounts of oxygen and Er are present in 'as-grown' films indicating that the majority of Er dopants probably exist as Er-O complexes in the material. Er(+3) luminescence at 1.54 micrometers was measured from the as-grown films, but ion implantation of additional oxygen decreases the emission intensity. Electrical compensation of n-type GaAs layers codoped with Er and Si is directly correlated to the Er concentration is proposed to arise from the deep centers associated with Er which are responsible for a broad emission band near 0.90 micrometers present in the photoluminescence spectra of GaAs:Si, Er films.

  20. REVIEW ARTICLE: Slow and fast light based on coherent population oscillations in erbium-doped fibres

    NASA Astrophysics Data System (ADS)

    Arrieta-Yáñez, Francisco; Calderón, Oscar G.; Melle, Sonia

    2010-10-01

    In this paper we review the main results on slow and fast light induced by coherent population oscillations in optical fibres doped with erbium ions. We explain the physics behind this technique and we describe the experimental realization. Finally, we summarize some recent advances in this field and future goals.

  1. Flat-Gain Wide-Band Erbium Doped Fiber Amplifier by Combining Two Difference Doped Fibers

    NASA Astrophysics Data System (ADS)

    Hamida, B. A.; Azooz, S. M.; Jasim, A. A.; Eltaif, T.; Ahmad, H.; Khan, S.; Harun, S. W.

    2015-03-01

    A new erbium-doped fibre amplifier (EDFA) is demonstrated using a combination of newly developed Erbium Zirconia co-doped fiber (Zr-EDF) and the commercial silica-based Erbium-doped fiber (Si-EDF) as the gain medium. Both fibers have a very high concentration of erbium ion. A compact amplifier operating in C-band region is firstly reported using a double-pass configuration. It is shown that average gains of the proposed Zr-EDF amplifier are obtained at approximately 18 dB with a gain variation of ±2 dB within C-band region. A flat-gain and wide band operation is achieved by configuring the amplifier in two stages comprising a 2 m long Zr-EDF and 9 m long Si-EDF optimised for C- and L-band operations, respectively, in a double-pass parallel configuration. A chirp fibre Bragg grating (CFBG) is used in both stages to ensure double propagation of the signal and thus to increase the attainable gain in both C- and L-band regions. At an input signal power of 0 dBm, a flat gain of 15 dB is achieved with a gain variation of less than 0.5 dB within a wide wavelength range from 1530 to 1605 nm. The corresponding noise figure varies from 6.2 to 10.8 dB within this wavelength region.

  2. Microwave photonic filter using multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency shift

    NASA Astrophysics Data System (ADS)

    Loh, K. K.; Yeo, K. S.; Shee, Y. G.

    2015-04-01

    A microwave photonic filter based on double-Brillouin-frequency spaced multiwavelength Brillouin-erbium fiber laser (BEFL) is experimentally demonstrated. The filter selectivity can be easily adjusted by tuning and apodizing the optical taps generated from the multiwavelength BEFL. Reconfiguration of different frequency responses are demonstrated.

  3. Erbium:YAG laser contouring of the nasal dorsum: a preliminary investigation

    NASA Astrophysics Data System (ADS)

    Truong, Mai T.; Majaron, Boris; Pandoh, Nidhi S.; Wong, Brian J.

    2001-05-01

    In conventional aesthetic rhinoplasty operations, manual or powered rasps are used to reduce the osseo-cartilagenous nasal dorsum. This tactile method requires palpation of the instrument and the dorsum during surgery to estimate the degree of volume reduction, and often requires forceful manipulation of the dorsum which may illicit pain during surgery and contribute to post-operative edema and echymosis. In this preliminary study, we investigated the use of the Erbium:YAG laser ((lambda) equals294 micrometers ) to reduce bone and cartilage using ex-vivo porcine nasal dorsum and human cadaveric tissues. The short pulsed length and high absorption of this laser in biologic tissues results in minimization of thermal injury which are ideal for non- contact optical contouring of osseous and cartilagenous tissues in the face. Two Erbium:YAG lasers were used to ablate fresh porcine nasal bone and compared for their use. One Erbium:YAG laser, the Fidelis Laser, Fontana Medical Lasers, Ljubljana, Slovenija with variable pulse repetition rates (2 to 50 Hz), pulse energy (80 to 1000 mJ), and pulse duration (100, 300, 750 and 1000 microsecond(s) ) was used and compared to the Ultrafine Erbium:YAG laser, Coherent Inc., Santa Clara California, with variable pulse repetition rate (2 to 10 Hz), pulse energy (2-16 J/cm2), and spot diameter (2-6 mm). Only laser parameters approximating the conditions for thermal confinement were evaluated.

  4. Ultrasonic approach for formation of erbium oxide nanoparticles with variable geometries.

    PubMed

    Radziuk, Darya; Skirtach, André; Gessner, Andre; Kumke, Michael U; Zhang, Wei; Möhwald, Helmuth; Shchukin, Dmitry

    2011-12-01

    Ultrasound (20 kHz, 29 W·cm(-2)) is employed to form three types of erbium oxide nanoparticles in the presence of multiwalled carbon nanotubes as a template material in water. The nanoparticles are (i) erbium carboxioxide nanoparticles deposited on the external walls of multiwalled carbon nanotubes and Er(2)O(3) in the bulk with (ii) hexagonal and (iii) spherical geometries. Each type of ultrasonically formed nanoparticle reveals Er(3+) photoluminescence from crystal lattice. The main advantage of the erbium carboxioxide nanoparticles on the carbon nanotubes is the electromagnetic emission in the visible region, which is new and not examined up to the present date. On the other hand, the photoluminescence of hexagonal erbium oxide nanoparticles is long-lived (μs) and enables the higher energy transition ((4)S(3/2)-(4)I(15/2)), which is not observed for spherical nanoparticles. Our work is unique because it combines for the first time spectroscopy of Er(3+) electronic transitions in the host crystal lattices of nanoparticles with the geometry established by ultrasound in aqueous solution of carbon nanotubes employed as a template material. The work can be of great interest for "green" chemistry synthesis of photoluminescent nanoparticles in water. PMID:22022886

  5. Microwave photonic filter using multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency shift

    SciTech Connect

    Loh, K. K.; Yeo, K. S.; Shee, Y. G.

    2015-04-24

    A microwave photonic filter based on double-Brillouin-frequency spaced multiwavelength Brillouin-erbium fiber laser (BEFL) is experimentally demonstrated. The filter selectivity can be easily adjusted by tuning and apodizing the optical taps generated from the multiwavelength BEFL. Reconfiguration of different frequency responses are demonstrated.

  6. Performance of a High-Concentration Erbium-Doped Fiber Amplifier with 100 nm Amplification Bandwidth

    SciTech Connect

    Hajireza, P.; Shahabuddin, N. S.; Abbasi-Zargaleh, S.; Emami, S. D.; Abdul-Rashid, H. A.; Yusoff, Z.

    2010-07-07

    Increasing demand for higher bandwidth has driven the need for higher Wavelength Division Multiplexing (WDM) channels. One of the requirements to achieve this is a broadband amplifier. This paper reports the performance of a broadband, compact, high-concentration and silica-based erbium-doped fiber amplifier. The amplifier optimized to a 2.15 m long erbium-doped fiber with erbium ion concentration of 2000 ppm. The gain spectrum of the amplifier has a measured amplification bandwidth of 100 nm using a 980 nm laser diode with power of 150 mW. This silica-based EDFA shows lower noise figure, higher gain and wider bandwidth in shorter wavelengths compared to Bismuth-based EDFA with higher erbium ion concentration of 3250 ppm at equivalent EDF length. The silica-based EDF shows peak gain at 22 dB and amplification bandwidth between 1520 nm and 1620 nm. The lowest noise figure is 5 dB. The gain is further improved with the implementation of enhanced EDFA configurations.

  7. Erbium-ion implantation into various crystallographic cuts of Al2O3

    NASA Astrophysics Data System (ADS)

    Nekvindova, P.; Mackova, A.; Malinsky, P.; Cajzl, J.; Svecova, B.; Oswald, J.; Wilhelm, R. A.

    2015-12-01

    This paper reports on the importance of crystallographic cuts with a different orientation on the luminescent properties and structural changes of Al2O3 implanted with Er+ ions at 190 keV and with a fluence of 1.0 × 1016 cm-2. Post-implantation annealing at 1000 °C in oxygen atmosphere was also done. The chemical compositions and erbium concentration-depth profiles of implanted layers were studied by Rutherford Backscattering Spectrometry (RBS) and compared to SRIM simulations. The same value of the maximum erbium concentration (up to 2 at.%) was observed at a depth of about 40 nm for all crystallographic cuts. The structural properties of the prepared layers were characterised by RBS/channelling. The relative amount of disordered atoms of 70-80% was observed in the prepared implanted layers and discussed for various cuts. It has been found that erbium is positioned randomly in the Al2O3 crystalline matrix, and no preferential positions appeared even after the annealing procedure. Erbium luminescence properties were measured in the wavelength range of 1440-1650 nm for all samples. As-implanted Al2O3 samples had a significant luminescence band at 1530 nm. The best luminescence was repeatedly observed in the <0 0 0 1> cut of Al2O3. The annealing procedure significantly improved the luminescent properties.

  8. Microscopic analysis of laser-induced proximal fiber tip damage during holmium:YAG and thulium fiber laser lithotripsy

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

    2016-04-01

    The thulium fiber laser (TFL) is being studied as an alternative to the standard holmium:YAG laser for lithotripsy. The TFL beam originates within an 18-μm-core thulium-doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller (e.g., 50- to 150-μm core) fibers than possible during holmium laser lithotripsy. This study examines whether the more uniform TFL beam profile also reduces proximal fiber tip damage compared with the holmium laser multimodal beam. Light and confocal microscopy images were taken of the proximal surface of each fiber to inspect for possible laser-induced damage. A TFL beam at a wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, and 500-μs pulse duration, and 100,000 pulses were delivered at each pulse rate setting of 50, 100, 200, 300, and 400 Hz. For comparison, single use, 270-μm-core fibers were collected after clinical holmium laser lithotripsy procedures performed with standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output pulse energy and average power were stable, and no proximal fiber damage was observed at settings up to 35 mJ, 400 Hz, and 14 W average power (n=5). In contrast, confocal microscopy images of fiber tips after holmium lithotripsy showed proximal fiber tip degradation, indicated by small ablation craters on the scale of several micrometers in all fibers (n=20). In summary, the proximal fiber tip of a 105-μm-core fiber transmitted up to 14 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially translate into lower costs for the surgical disposables as well.

  9. Synthesis and optical properties of antimony oxide glasses doped with holmium trioxide

    NASA Astrophysics Data System (ADS)

    Raghunatha, S.; Eraiah, B.

    2016-05-01

    Holmium doped lithium-antimony-lead borate glasses having 1mol% AgNO3 with composition 50B2O3-20PbO-25Sb2O3-5Li2O have been prepared using single step melt quenching technique. The XRD spectrum confirms amorphous nature of glasses. The optical absorbance studies were carried out on these glasses. The optical direct band gap energies were found to be in the range of 3.10 eV to 3.31 eV and indirect band gap energies were found to be in the range of 2.28 eV to 3.00 eV. The refractive indexes have been calculated by using Lorentz-Lorenz formula and the calculated values in the range of 2.31 to 2.37.

  10. Quantum theory of the anisotropy of the magnetic properties of ferrimagnetic holmium iron garnet single crystals.

    PubMed

    Yang, Jiehui; Ma, Shengcan; Xu, You

    2009-03-01

    The pronounced anisotropy of the magnetization caused by the Ho(3+) ions in the ferrimagnetic holmium iron garnet has been investigated based on quantum theory. The strong anisotropy of the magnetization of the Ho(3+) ions originates mainly from the effect of the crystal field upon the Ho(3+) ions and the anisotropic Ho(3+)-Fe(3+) superexchange interaction. Following the expression of the Yb(3+)-Fe(3+) exchange interaction used by Alben, the anisotropy of the Ho(3+)-Fe(3+) exchange interaction is defined by three principal values of the exchange tensor G. Because the six Ho(3+) sublattices are magnetically non-equivalent, we calculate the magnetic quantities of the Ho(3+) at the six sublattices and compare the average value of the so-obtained six quantities with the measured values. The calculated results are in good agreement with experiments. An interpretation on the anisotropy of the magnetic properties of HoIG is given. PMID:21817410

  11. Emission spectrum of holmium atoms excited during ionic sputtering of a surface

    SciTech Connect

    Pop, S. S.; Braslavets, V. V.; Evdokimov, S. A.

    1988-08-01

    The article shows the fundamental possibility of using the bombardment of the surface of solids by kilo V ions for exciting the emission spectrum of particles of the target material and for obtaining spectroscopic data. The method is tested by studying the emission spectra of holmium as an example. It is shown that the sensitivity of the method can be substantially increased by using the so-called chemical effect, i.e., the effect of strengthening the spectral lines of sputtered excited metal atoms during bombardment of the target in the presence of oxygen. It is proposed that the chemical effect, which takes place only for atomic lines, in contrast to ionic ones, can also be used for simplifying the identification of atomic lines. It is noted that the proposed method is suitable for studying the atomic spectra of any solids, including refractory and chemically reactive substances.

  12. Holmium Laser Enucleation of the Prostate in a 400 cc Prostate: Case Report.

    PubMed

    Gopee, Esha L; Hong, Matthew K H; Pham, Trung

    2016-01-01

    The modality of choice in the surgical management of benign prostatic hyperplasia for large prostates has traditionally been open prostatectomy. Advances in minimally invasive techniques have begun to challenge this notion with advantages such as lower bleeding and transfusion rates and shorter hospital stay. In this case report, we illustrate the use of holmium laser enucleation of the prostate (HoLEP) in a gland measuring more than 400 cc. We describe the case of a 71-year-old man with persistent voiding urinary symptoms despite two previous transurethral resections of his prostate. With greater experience in HoLEP and declining experience in open prostatectomy, there may be a shift toward HoLEP as the preferred treatment choice for large prostate glands. PMID:27579406

  13. Acute and chronic response of meniscal fibrocartilage to holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Horan, Patrick J.; Popovic, Neven A.; Islinger, Richard B.; Kuklo, Timothy R.; Dick, Edward J.

    1997-05-01

    The acute and chronic (10 week) histological effects of the holmium:YAG laser during partial meniscectomy in an in vivo rabbit model were investigated. Twenty-four adult male New Zealand rabbits underwent bilateral parapatellar medial knee arthrotomies. In the right knee, a partial medial meniscectomy was done through the avascular zone using a standard surgical blade. In the left knee, an anatomically similar partial medial meniscectomy was performed using a Ho:YAG laser (Coherent, USA). This study indicates that the laser creates two zones of damage in the meniscal fibrocartilage and that the zone of thermal change may act as a barrier to healing. The zone of thermal change which is eventually debrided was thought at the time of surgery to be viable. In the laser cut menisci, the synovium appears to have greater inflammation early and to be equivalent with the scalpel cut after three weeks. At all time periods there appeared more cellular damage in the laser specimens.

  14. Holmium Laser Enucleation of the Prostate in a 400 cc Prostate: Case Report

    PubMed Central

    Hong, Matthew K.H.; Pham, Trung

    2016-01-01

    Abstract The modality of choice in the surgical management of benign prostatic hyperplasia for large prostates has traditionally been open prostatectomy. Advances in minimally invasive techniques have begun to challenge this notion with advantages such as lower bleeding and transfusion rates and shorter hospital stay. In this case report, we illustrate the use of holmium laser enucleation of the prostate (HoLEP) in a gland measuring more than 400 cc. We describe the case of a 71-year-old man with persistent voiding urinary symptoms despite two previous transurethral resections of his prostate. With greater experience in HoLEP and declining experience in open prostatectomy, there may be a shift toward HoLEP as the preferred treatment choice for large prostate glands. PMID:27579406

  15. Application of 2-um wavelength holmium lasers for treatment of skin diseases

    NASA Astrophysics Data System (ADS)

    Shcherbakov, Ivan A.; Klimov, Igor V.; Tsvetkov, Vladimir B.; Nerobeev, Alexander I.; Sadovnikova, Lija B.; Eliseenko, Vladimir I.

    1994-09-01

    Theoretical and experimental analysis of the efficiency of application of 2 micrometers pulsed holmium laser for cosmetic and plastic surgery and dermatology is carried out. Preliminary experiments were carried out on rats. Solid state 2 micrometers pulsed laser was allowed to operate in free running mode with pulse energy up to 1.5 J and pulse repetition rate up to 5 Hz. To deliver emission to the object a flexible quartz fiber without further focusing of 2.5 m in length and 400 micrometers of the core diameter was used. The effect of the different power density emission on the skin was studied. The second stage was the study of the influence of 2 micrometers emission on human skin. The results of the removal of hemangioma, papilloma, telangiectasia, nevus, nevus acantholytic, xanthelasma palpebral, verruca, chloasma, pigmental spots, tattoos, etc. are presented. Precision, simplicity, efficiency, and the high cosmetic effect of these operations is noted.

  16. Cavitation effect of holmium laser pulse applied to ablation of hard tissue underwater.

    PubMed

    Lü, Tao; Xiao, Qing; Xia, Danqing; Ruan, Kai; Li, Zhengjia

    2010-01-01

    To overcome the inconsecutive drawback of shadow and schlieren photography, the complete dynamics of cavitation bubble oscillation or ablation products induced by a single holmium laser pulse [2.12 microm, 300 micros (FWHM)] transmitted in different core diameter (200, 400, and 600 microm) fibers is recorded by means of high-speed photography. Consecutive images from high-speed cameras can stand for the true and complete process of laser-water or laser-tissue interaction. Both laser pulse energy and fiber diameter determine cavitation bubble size, which further determines acoustic transient amplitudes. Based on the pictures taken by high-speed camera and scanned by an optical coherent microscopy (OCM) system, it is easily seen that the liquid layer at the distal end of the fiber plays an important role during the process of laser-tissue interaction, which can increase ablation efficiency, decrease heat side effects, and reduce cost. PMID:20799845

  17. STM and ab initio study of holmium nanowires on a Ge(111) surface

    NASA Astrophysics Data System (ADS)

    Eames, C.; Bonet, C.; Probert, M. I. J.; Tear, S. P.; Perkins, E. W.

    2006-11-01

    A nanorod structure has been observed on the Ho/Ge(111) surface using scanning tunneling microscopy (STM). The rods do not require patterning of the surface or defects such as step edges in order to grow as is the case for nanorods on Si(111). At low holmium coverage the nanorods exist as isolated nanostructures while at high coverage they form a periodic 5×1 structure. We propose a structural model for the 5×1 unit cell and show using an ab initio calculation that the STM profile of our model structure compares favorably to that obtained experimentally for both filled and empty states sampling. The calculated local density of states shows that the nanorod is metallic in character.

  18. Operation of the nose using Nd-YAG and holmium laser

    NASA Astrophysics Data System (ADS)

    Kukwa, Andrzej; Tulibacki, Marek P.; Zajac, Andrzej; Dudziec, Katarzyna

    2000-06-01

    During more than 5 years Nd:YAG and Holmium laser has been used in our ENT Department for the treatment of varies pathological changes. Most of our cases were previously treated many times because of recurrences of the nasal polyps. As a rule the treatment was given in one to three sessions. Each patient was very closely monitored. The time period between the session was 2-4 weeks. The consequent application of laser was dependent on healing process. All adults' patients were treated in local anesthesia using 1,5 percent of Cocaine and 10 percent Xylocaine applied in a spray; no other anesthetics were needed, although in some patients 10 mg Valium was administered before first session of laser application. We do not observe a severe bleeding needed sponge or a nose package. Among advantages we have to concentrate on two: the recurrences of nasal polyps are definitely much rare and patient may appear at work at the same day.

  19. High power operation of cladding pumped holmium-doped silica fibre lasers.

    PubMed

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency. PMID:23481989

  20. Holmium:YAG laser: effect on pulpal tissues and root surfaces

    NASA Astrophysics Data System (ADS)

    Holt, Raleigh A.; Nordquist, Robert E.

    1996-04-01

    The effects of the Holmium:YAG irradiation on the pulpal tissues and surface topography on root surface dentin in human teeth in vivo were studied. The exposed root surfaces of seventeen pre-immediate denture patients were scaled and root planed with a Gracey 3 - 4 curette apical to the dentinoenamel junction until smooth and hard. The prepared root surfaces of two teeth per patient were exposed with Holmium:YAG laser energy after an application of nonfilled resin/fluoride mixture. The laser exposed areas were below the dentinoenamel junction around one-half of each root surface. The opposing sides of each of the teeth received resin/fluoride but no laser energy. A third tooth was identified as a nontreated control. The HO:YAG at 2.12 microns wavelength with a defocused beam size of 3 mm was used. The amount of laser energy delivered per 3 X 5 mm area was 0.450 (+/- .05) joules with a fluence of 2.66 - 3.30 J/cm2. The teeth were extracted after periods of 45 - 120 days. The specimens were fixed in formalin and prepared for histological examination using hematoxylin and eosin stains. Microscopic evaluation of room surfaces showed increased smoothness on the laser treated sites compared to their opposing non-lased sides. Histological examination of the pulpal tissues exhibited no abnormal changes. No clinical symptoms of pulpal pathology were produced. HO:YAG laser energy proved safe for treating room surfaces of human teeth in vivo under conditions presented in this study.

  1. Risk factors of infectious complications following flexible ureteroscope with a holmium laser: a retrospective study

    PubMed Central

    Fan, Song; Gong, Binbin; Hao, Zongyao; Zhang, Li; Zhou, Jun; Zhang, Yifei; Liang, Chaozhao

    2015-01-01

    Purpose: We aimed to evaluate the effectiveness of flexible ureteroscope for treating kidney stones and the risk factors for infectious complications following flexible ureteroscope (FURS) with a holmium laser. Methods: We retrospectively reviewed the data of 227 patients with kidney stones who underwent flexible ureteroscope with a holmium laser at our hospital from January 2012 to September 2014, including gender, age, comorbidity, urine analysis results, urine culture results, blood test results, stone size, operative duration, and residual stones. Patients with and without infectious complications were assigned to groups A and B, respectively. The dependent variables were postoperative infectious complications, and the risk factors for infectious complications following FURS were assessed using Chi-square tests and multivariate logistic regression analyses. Results: All the surgeries were successfully completed. The total stone-free rate was 81.9% (n = 186), and the incidence of infectious complications after FURS was 8.37% (n = 19). Fifteen patients (6.61%) developed fever postoperatively, 10 patients (4.41%) developed systemic inflammatory response syndrome (SIRS), 6 patients with fever were considered to have SIRS (2.64%), and 2 patients had sepsis (0.88%). Univariate analyses of groups A and B indicated that pyuria, stone size, operative duration, and infectious stones were risk factors for infectious complications after FURS (P < 0.05). Multivariate logistic regression analyses indicated that pyuria (P = 0.017), operative duration (P = 0.026), and infectious stones (P = 0.030) were independently related to infectious complications. Conclusion: Pyuria, operative duration, and infectious stones were risk factors for infectious complications following FURS. Hence, routine urinalysis findings should be carefully considered, particularly the finding of pyuria. PMID:26379932

  2. Percutaneous Transhepatic Endoscopic Holmium Laser Lithotripsy for Intrahepatic and Choledochal Biliary Stones

    SciTech Connect

    Rimon, Uri; Kleinmann, Nir; Bensaid, Paul; Golan, Gil; Garniek, Alexander; Khaitovich, Boris; Winkler, Harry

    2011-12-15

    Purpose: To report our approach for treating complicated biliary calculi by percutaneous transhepatic endoscopic biliary holmium laser lithotripsy (PTBL). Patients and Methods: Twenty-two symptomatic patients (11 men and 11 women, age range 51 to 88 years) with intrahepatic or common bile duct calculi underwent PTBL. Nine patients had undergone previous gastrectomy and small-bowel anastomosis, thus precluding endoscopic retrograde cholangiopancreatography. In the other 13 patients, stone removal attempts by ERCP failed due to failed access or very large calculi. We used a 7.5F flexible ureteroscope and a 200-{mu}m holmium laser fiber by way of a percutaneous transhepatic tract, with graded fluoroscopy, to fragment the calculi with direct vision. Balloon dilatation was added when a stricture was seen. The procedure was performed with the patient under general anaesthesia. A biliary drainage tube was left at the end of the procedure. Results: All stones were completely fragmented and flushed into the small bowel under direct vision except for one patient in whom the procedure was aborted. In 18 patients, 1 session sufficed, and in 3 patients, 2 sessions were needed. In 7 patients, balloon dilatation was performed for benign stricture after Whipple operation (n = 3), for choledochalenteric anastomosis (n = 3), and for recurrent cholangitis (n = 1). Adjunctive 'balloon push' (n = 4) and 'rendezvous' (n = 1) procedures were needed to completely clean the biliary tree. None of these patients needed surgery. Conclusion: Complicated or large biliary calculi can be treated successfully using PTBL. We suggest that this approach should become the first choice of treatment before laparoscopic or open surgery is considered.

  3. Correlation of thermal and mechanical effects of the holmium laser for various clinical applications

    NASA Astrophysics Data System (ADS)

    Grimbergen, Matthijs C. M.; Verdaasdonck, Rudolf M.; van Swol, Christiaan F. P.

    1998-05-01

    The Holmium laser has become established in orthopedic surgery and urology due to its unique combination of mechanical and thermal properties induced by explosive vapor bubbles. In a specialized setup, real-time high-speed and thermal images of dynamic vapor bubbles and thermal relaxation at a water tissue interface were obtained simultaneously. The thermal effects in the tissue model were correlated to the characteristics of the bubbles dependent on pulse energy (0.2 - 4 J), pulse repetition frequency (5 - 40 Hz), distance and angle of fiber delivery system (diameter 365 micrometer) to the tissue surface. Up to a fiber-to-tissue distance of 50% of the radius of the bubble, only a superficial tissue layer was heated. During bubble implosion, the tissue surface was attracted to the fiber, ripping of irregularities, and was effectively cooled by turbulence. In case of hard tissues, the bubble detached from the fiber imploding towards the hard surface. At closer distances (less than 50% of bubble radius), the tissue itself was vaporized resulting in mechanical damage and thermal relaxation into the tissue, especially above repetition rates of 5 Hz. There is a strong correlation between the path length of the free beam within the bubble and the degree of mechanical and thermal damage in the tissue directly irradiated by this beam. During clinical applications the surgeon should be aware of the size of the vapor bubble in relation to the distance and angle with the tissue for safe optimal use of the mechanical and thermal properties of the Holmium laser.

  4. Intracavitary Radiation Therapy for Recurrent Cystic Brain Tumors with Holmium-166-Chico : A Pilot Study

    PubMed Central

    Ha, Eun Jin; Rhee, Chang Hun; Youn, Sang Min; Choi, Chang-Woon; Cheon, Gi Jeong

    2013-01-01

    Objective Intracavitary injection of beta-emitting radiation source for control of cystic tumors has been tried with a benefit of localized internal radiation. The authors treated cystic brain tumor patients with Holmium-166-chitosan complex (Ho-166-chico), composed of a beta-emitting radionuclide Holmium-166 and biodegradable chit polymer, and evaluated the safety and effective measurement for response. Methods Twenty-two patients with recurrent cystic brain tumor and/or located in a deep or eloquent area were enrolled in this pilot study. The cyst volume and wall thickness were determined on CT or MRI to assess radiological response. The activity of Ho-166-chico injected via Ommaya reservoir was prescribed to be 10-25 Gy to the cyst wall in a depth of 4 mm. Results There was neither complications related to systemic absorption nor leakage of Ho-166-chico in all 22 patients. But, two cases of oculomotor paresis were observed in patients with recurrent craniopharyngioma. Radiological response was seen in 14 of 20 available follow-up images (70%). Seven patients of 'evident' radiological response experienced more than 25% decrease of both cyst volume and wall thickness. Another 7 patients with 'suggestive' response showed decrease of cyst volume without definitive change of the wall thickness or vice versa. All patients with benign tumors or low grade gliomas experienced symptomatic improvement. Conclusion Ho-166-chico intracavitary radiation therapy for cystic tumor is a safe method of palliation without serious complications. The determination of both minimal effective dosage and time interval of repeated injection through phase 1 trial could improve the results in the future. PMID:24278644

  5. Erbium:YAG-laser induced vapor bubbles as a function of the quartz fiber tip geometry

    NASA Astrophysics Data System (ADS)

    Mrochen, Michael; Riedel, Peter; Donitzky, Christof; Seiler, Theo

    2001-07-01

    Background. The use of modern erbium: yttrium-aluminum- garnet (YAG) laser systems in ophthalmic microsurgery requires a precise knowledge of the size and dynamics of the laser induced vapor bubbles. The aim of this work was to clarify the possibilities of controlling the vapor bubble shape and size by using an optimized fiber tip geometry for various ophthalmic applications with the erbium:YAG laser. Methods. The mid-infrared radiation of free-running erbium:YAG laser was coupled optically into means of different low OH- quartz fiber tips to investigate the vapor bubble formation in water by high-speed photography. The core diameter of four fiber tips ranged from 200 up to 940 micrometers . Fourteen fiber tips were polished at an angle graduated from 10 degree(s) to 70 degree(s) over the full core diameter (seven fiber tips) and over the half core diameter (seven fiber tips). Three fiber tips were produced to have a curvature at the distal end with curvature radii of 160, 230, and 420 micrometers . Results. The shape as well as the size of erbium:YAG laser induced vapor bubbles can be controlled systematically by using adequate fiber tip geometries. In detail, the used different angles and curvatures demonstrate that the propagation direction of the vapor bubbles can be estimated by optical modeling considering Snell's law and the Fresnel laws at a quartz-air boundary. Beside this, the size of a vapor bubble can be predetermined by choosing ideal fiber tip geometries to reduce or increase the radiant exposure at the distal end of the quartz fiber tip. Conclusions. The good possibility of controlling the shape and size of vapor bubbles offers a wider range of new applications, especially in ophthalmic microsurgery such as erbium YAG laser vitrectomy.

  6. Synthesis Mechanism of Low-Voltage Praseodymium Oxide Doped Zinc Oxide Varistor Ceramics Prepared Through Modified Citrate Gel Coating

    PubMed Central

    Abdullah, Wan Rafizah Wan; Zakaria, Azmi; Ghazali, Mohd Sabri Mohd

    2012-01-01

    High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr6O11) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr6O11 addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr6O11 from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr6O11 content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary. PMID:22606043

  7. Concentration quenching of praseodymium ions Pr(3+) in BaGd2(MoO4)4 crystals.

    PubMed

    Guan, Ying; Tsuboi, Taiju; Huang, Yanlin; Huang, Wei

    2014-03-01

    The concentration effect on the photoluminescence (PL) of the praseodymium Pr(3+) ion is studied at 298-12 K for barium gadolinium molybdate (BaGd2(MoO4)4, called BGM) crystals with a wide Pr(3+) concentration range of 0.05-25.0 mol%. Three types of concentration dependences are observed for the emissions although all types show PL quenching at high concentrations. The first type (Type A) has the maximum PL intensity at about 10 mol% with a non-zero intensity at high concentrations, which is observed for the (3)P0 emissions except for emission at 621 nm. The second and third types (Type B-1 and B-2) have the maximum at about 1 mol% with a finite residual intensity and nearly zero intensity at high concentrations, respectively, which are observed for the 621 nm emission and all the (1)D2 emissions. It is suggested that the energy migration mechanism is responsible for Type A, while the non-resonant cross-relaxation is responsible for Type B-1 and the resonant cross-relaxation for Type B-2. PMID:24429706

  8. Influence of praseodymium and nitrogen co-doping on the photocatalytic activity of TiO{sub 2}

    SciTech Connect

    Wu, Jing; Liu, Qingju; Gao, Pan; Zhu, Zhongqi

    2011-11-15

    Highlights: {yields} The praseodymium and nitrogen co-doped TiO{sub 2} (Pr-N-TiO{sub 2}) powders were prepared and characterized. {yields} The effects on the photocatalytic activity were studied. {yields} The results exhibit that the spectrum absorption region of the co-doped sample is red-shifted to visible light and the recombination of the photo-generated pairs is inhibited. {yields} The photocatalytic activity is greatly improved. -- Abstract: TiO{sub 2} nanoparticles co-doped with different doping concentration of Pr and N were prepared by sol-gel method combined with microwave chemical method. The samples were characterized by XRD, FT-IR, UV-vis, TEM, XPS, PL, and the photocatalytic activity were investigated by photocatalytic degradation of methylene blue (MB). The results indicate that Pr and N ions incorporate into the lattice of TiO{sub 2}, co-doping restrains the increase of grain size, broadens the absorption region to visible light, and inhibits the recombination of the photo-generated electrons and holes. Moreover, the photocatalytic activity of Pr-N-TiO{sub 2} is remarkable improved due to the synergistic effect of the co-doped ions. The degradation rate of MB in 6 h is 92.81%, which is much higher than that of Degussa P25 (45.01%).

  9. Laser-diode pumped self-mode-locked praseodymium visible lasers with multi-gigahertz repetition rate.

    PubMed

    Zhang, Yuxia; Yu, Haohai; Zhang, Huaijin; Di Lieto, Alberto; Tonelli, Mauro; Wang, Jiyang

    2016-06-15

    We demonstrate efficient laser-diode pumped multi-gigahertz (GHz) self-mode-locked praseodymium (Pr3+) visible lasers with broadband spectra from green to deep red for the first time to our knowledge. With a Pr3+-doped GdLiF4 crystal, stable self-mode-locked visible pulsed lasers at the wavelengths of 522 nm, 607 nm, 639 nm, and 720 nm have been obtained with the repetition rates of 2.8 GHz, 3.1 GHz, 3.1 GHz, and 3.0 GHz, respectively. The maximum output power was 612 mW with the slope efficiency of 46.9% at 639 nm. The mode-locking mechanism was theoretically analyzed. The stable second-harmonic mode-locking with doubled repetition frequency was also realized based on the Fabry-Perot effect formed in the laser cavity. In addition, we find that the polarization directions were turned with lasing wavelengths. This work may provide a new way for generating efficient ultrafast pulses with high- and changeable-repetition rates in the visible range. PMID:27304265

  10. Synthesis mechanism of low-voltage praseodymium oxide doped zinc oxide varistor ceramics prepared through modified citrate gel coating.

    PubMed

    Abdullah, Wan Rafizah Wan; Zakaria, Azmi; Ghazali, Mohd Sabri Mohd

    2012-01-01

    High demands on low-voltage electronics have increased the need for zinc oxide (ZnO) varistors with fast response, highly non-linear current-voltage characteristics and energy absorption capabilities at low breakdown voltage. However, trade-off between breakdown voltage and grain size poses a critical bottle-neck in the production of low-voltage varistors. The present study highlights the synthesis mechanism for obtaining praseodymium oxide (Pr(6)O(11)) based ZnO varistor ceramics having breakdown voltages of 2.8 to 13.3 V/mm through employment of direct modified citrate gel coating technique. Precursor powder and its ceramics were examined by means of TG/DTG, FTIR, XRD and FESEM analyses. The electrical properties as a function of Pr(6)O(11) addition were analyzed on the basis of I-V characteristic measurement. The breakdown voltage could be adjusted from 0.01 to 0.06 V per grain boundary by controlling the amount of Pr(6)O(11) from 0.2 to 0.8 mol%, without alteration of the grain size. The non-linearity coefficient, α, varied from 3.0 to 3.5 and the barrier height ranged from 0.56 to 0.64 eV. Breakdown voltage and α lowering with increasing Pr(6)O(11) content were associated to reduction in the barrier height caused by variation in O vacancies at grain boundary. PMID:22606043

  11. Acute abdominal compartment syndrome as a complication of Holmium laser enucleation of the prostate: a case report

    PubMed Central

    2014-01-01

    Background In 1996, Holmium laser enucleation of the prostate was introduced and has been shown to be safe and highly effective. Case presentation We report a case of a rare complication that resulted in intra-abdominal compartment syndrome with prolonged intubation and intensive care, involving an 74-year-old male after holmium laser enucleation of prostate, with a massive irrigant fluid leakage into the retroperitoneal space. The elevated abdominal pressure was reduced by forced diuresis. The tracheal tube was removed 18 hours after the patient’s transfer to the ICU. The patient was discharged to home one week after the operation. Conclusion In rare cases when no obvious ruptures of the prostate capsule or the bladder occur during laser enucleation of prostate, knowledge regarding possible emersion of massive amounts of irrigant fluid into the retroperitoneal space leading to intra-abdominal compartment syndrome aids in the diagnosis and subsequent successful therapy of intra-abdominal hypertension. PMID:24910537

  12. Comparison of the erbium-yttrium aluminum garnet and carbon dioxide lasers for in vitro bone and cartilage ablation

    SciTech Connect

    Gonzalez, C.; van de Merwe, W.P.; Smith, M.; Reinisch, L. )

    1990-01-01

    The in vitro bone- and cartilage-ablation characteristics of the solid-state erbium:yttrium aluminum garnet laser were compared to those of the carbon dioxide laser. Ablations of fresh, frozen cadaver septal cartilage and maxillary sinus bone were performed using total energies between 1 and 6 J. Specimens were studied using hematoxylin and eosin stain and digitized, computer-assisted measurements of 35-mm photographs. Erbium-yttrium aluminum garnet-ablated bone averaged 5 microns of adjacent tissue thermal injury, compared with 67 microns with carbon dioxide-ablated bone. Erbium-yttrium aluminum garnet-ablated cartilage averaged 2 microns of adjacent tissue thermal injury, compared with 21 microns with the carbon dioxide-ablated cartilage. The tissue-ablation characteristics of the erbium-yttrium aluminum garnet laser are promising for future otolaryngologic applications.

  13. Q-switching of a thulium-doped fibre laser using a holmium-doped fibre saturable absorber

    SciTech Connect

    Sadovnikova, Ya E; Kamynin, V A; Kurkov, A S; Medvedkov, O I; Marakulin, A V; Minashina, L A

    2014-01-31

    We have proposed and demonstrated a new passively Q-switched thulium-doped fibre laser configuration. A distinctive feature of this configuration is the use of a heavily holmium-doped fibre for Q-switching. Lasing was obtained at 1.96 μm, with a pulse energy of 3 μJ and pulse duration of 600 ns. The highest pulse repetition rate was 80 kHz. (control of laser radiation parameters)

  14. Coupling of erbium dopants to yttrium orthosilicate photonic crystal cavities for on-chip optical quantum memories

    NASA Astrophysics Data System (ADS)

    Miyazono, Evan; Zhong, Tian; Craiciu, Ioana; Kindem, Jonathan M.; Faraon, Andrei

    2016-01-01

    Erbium dopants in crystals exhibit highly coherent optical transitions well suited for solid-state optical quantum memories operating in the telecom band. Here, we demonstrate coupling of erbium dopant ions in yttrium orthosilicate to a photonic crystal cavity fabricated directly in the host crystal using focused ion beam milling. The coupling leads to reduction of the photoluminescence lifetime and enhancement of the optical depth in microns-long devices, which will enable on-chip quantum memories.

  15. Efficacy of Holmium Laser Urethrotomy in Combination with Intralesional Triamcinolone in the Treatment of Anterior Urethral Stricture

    PubMed Central

    Kapoor, Ankur; Ganesamoni, Raguram; Nanjappa, Bhuvanesh; Sharma, Varun; Mete, Uttam K

    2012-01-01

    Purpose To evaluate the outcome of visual internal urethrotomy with a holmium:yttrium-aluminum-garnet laser along with intralesional triamcinolone injection. Materials and Methods Patients with an anterior urethral stricture less than 3 cm in length were evaluated by clinical history, physical examination, uroflowmetry, and retrograde urethrogram preoperatively. All patients were treated with holmium laser urethrotomy and intralesional triamcinolone (80 mg) injection under general or regional anesthesia. An 18 F urethral catheter was placed for 5 days. All patients were followed up for 12 months postoperatively by history, uroflowmetry, and if required, retrograde urethrogram or urethroscopy every 3 months. Results The mean age of the patients was 42.9 years (range, 14 to 70 years). The overall recurrence rate was 24%. The success rate in patients with strictures less than 1 cm in length was 95.8%, whereas that in patients with strictures of 1 to 3 cm in length was 57.7% (p=0.002). The outcome did not depend on age, duration of symptoms, etiology, or location of stricture. Conclusions Holmium laser urethrotomy with intralesional triamcinolone is a safe and effective minimally invasive therapeutic modality for urethral strictures. This procedure has an encouraging success rate, especially in those with stricture segments of less than 1 cm in length. PMID:23060998

  16. Development of erbium phosphate doped poly(glycidyl methacrylate/ethylene dimethacrylate) spin columns for selective enrichment of phosphopeptides.

    PubMed

    Güzel, Yüksel; Rainer, Matthias; Messner, Christoph B; Hussain, Shah; Meischl, Florian; Sasse, Michael; Tessadri, Richard; Bonn, Günther K

    2015-05-01

    In this study, a novel method for the highly selective enrichment of phosphopeptides using erbium phosphate doped poly(glycidyl methacrylate/ethylene dimethacrylate) spin columns is presented. Erbium phosphate was synthesized by precipitation from boiling phosphoric acid and incubated overnight in erbium chloride solutions. The resulting powder was embedded in a monolithic poly(glycidyl methacrylate/ethylene dimethacrylate) polymer. The monolith was synthesized in a spin column by radical polymerization. Erbium phosphate demonstrated a high affinity and selectivity for phosphopeptides due to the strong interaction of trivalent erbium ions with the phosphate groups of phosphopeptides. The high selectivity and performance of the designed spin columns were demonstrated by successfully enriching phosphopeptides from tryptically digested protein mixtures containing the model phosphoproteins α- and β-casein, bovine milk, and human saliva. By the implementation of several washing steps, unspecific components were removed and the enriched phosphopeptides were effectively eluted from the spin columns under alkaline conditions. The selective performance of the presented method was further demonstrated by the enrichment of two synthetic phosphopeptides, which were spiked in tryptically digested and dephosphorylated HeLa cell lysates at low ratios. Finally, the presented approach was compared to conventional phosphopeptide enrichment by titanium oxide and revealed higher recoveries for the erbium phosphate doped monoliths. PMID:25645427

  17. Real-time synchrotoron radiation X-ray diffraction and abnormal temperature dependence of photoluminescence from erbium silicates on SiO{sub 2}/Si substrates

    SciTech Connect

    Omi, H.; Tawara, T.; Tateishi, M.

    2012-03-15

    The erbium silicate formation processes during annealing in Ar gas were monitored by synchrotron radiation grazing incidence X-ray diffraction (GIXD) in real time and the optical properties of the silicates were investigated by photoluminescence measurements in spectral and time-resolved domains. The GIXD measurements show that erbium silicates and erbium oxide are formed by interface reactions between silicon oxide and erbium oxides deposited on silicon oxide by reactive sputtering in Ar gas and O{sub 2}/Ar mixture gas ambiences. The erbium silicates are formed above 1060 degree sign C in Ar gas ambience and above 1010 degree sign C in O{sub 2}/Ar gas ambience, and erbium silicides are dominantly formed above 1250 degree sign C. The I{sub 15/2}-I{sub 13/2} Er{sup 3+} photoluminescence from the erbium oxide and erbium silicate exhibits abnormal temperature dependence, which can be explained by the phonon-assisted resonant absorption of the 532-nm excitation photons into the {sup 2}H{sub 11/2} levels of Er{sup 3+} ions of the erbium compounds.

  18. [Critical evaluation of indications for the holmium:YAG laser and the neodymium:YAG laser in orthopedic surgery based on an in vitro study].

    PubMed

    Anders, J O; Pietsch, S; Staupendahl, G

    1999-04-01

    This is an in vitro study of the biophysical effects of holmium:YAG and neodymium-YAG lasers that was prompted by the poor clinical results obtained with lumbar percutaneous laser discus decompression (PLDD). In the absence of adequate cooling, ablation of tissue with the holmium:YAG laser causes thermal damage to the surrounding tissues. Utilizing the immediate colour-independent laser coupling effect, the holmium:YAG laser removes soft and hard tissue immediately. The low tissue penetrating power (max. 0.32 mm), together with the use of irrigation, avoids thermal problems, and this laser type with its high pulse energy and frequency is to be recommended for arthroscopic surgery. In contrast, the effects of the neodymium:YAG laser are highly dependent on tissue colour. Using this laser on light-coloured tissue only diffuse warming but no ablation of soft tissue was often seen. The depth of tissue penetration seen in our study was 0.58 mm, but is greatly dependent on the duration of application, and is much larger with long application times. In conclusion, we believe that the neodymium:YAG laser is more suitable for percutaneous intradiscal procedures than the holmium:YAG laser. For arthroscopic surgery, the holmium:YAG laser will be the better choice. The effect of each type of laser depends not only on its physical properties, but also on tissue properties (light or dark-coloured, thermal conductivity) and duration of application. PMID:10379068

  19. The evaluation of tissue mass loss in the incision line of prostate with benign hyperplasia performed using holmium laser and cutting electrode

    PubMed Central

    Szewczyk, Mariusz; Jesionek–Kupnicka, Dorota; Lipinski, Piotr; Różański, Waldemar

    2014-01-01

    Introduction The aim of this study is to compare the changes in the incision line of prostatic adenoma using a monopolar cutting electrode and holmium laser, as well as the assessment of associated tissue mass and volume loss of benign prostatic hyperplasia (BPH). Material and methods The material used in this study consisted of 74 preparations of prostatic adenoma obtained via open retropubic adenomectomy, with an average volume of 120.7 ml. The material obtained cut in vitro before fixation in formaldehyde. One lobe was cut using holmium laser, the other using a monopolar cutting electrode. After the incision was made, tissue mass and volume loss were evaluated. Thermocoagulation changes in the incision line were examinedunder light microscope. Results In the case of the holmium laser incision, the average tissue mass loss was 1.73 g, tissue volume loss 3.57 ml and the depth of thermocoagulation was 1.17 mm. When the monopolar cutting electrode was used average tissue mass loss was 0.807 g, tissue volume loss 2.48 ml and the depth of thermocoagulation was 0.19 mm. Conclusions Where holmium laser was used, it was observed that the layer of tissue with thermocoagulation changes was deeper than in the case of the monopolar cutting electrode. Moreover, it was noticed that holmium laser caused bigger tissue mass and volume loss than the cutting electrode. PMID:25247088

  20. Superconducting composite with multilayer patterns and multiple buffer layers

    DOEpatents

    Wu, X.D.; Muenchausen, R.E.

    1993-10-12

    An article of manufacture is described including a substrate, a patterned interlayer of a material selected from the group consisting of magnesium oxide, barium-titanium oxide or barium-zirconium oxide, the patterned interlayer material overcoated with a secondary interlayer material of yttria-stabilized zirconia or magnesium-aluminum oxide, upon the surface of the substrate whereby an intermediate article with an exposed surface of both the overcoated patterned interlayer and the substrate is formed, a coating of a buffer layer selected from the group consisting of cerium oxide, yttrium oxide, curium oxide, dysprosium oxide, erbium oxide, europium oxide, iron oxide, gadolinium oxide, holmium oxide, indium oxide, lanthanum oxide, manganese oxide, lutetium oxide, neodymium oxide, praseodymium oxide, plutonium oxide, samarium oxide, terbium oxide, thallium oxide, thulium oxide, yttrium oxide and ytterbium oxide over the entire exposed surface of the intermediate article, and, a ceramic superconductor. 5 figures.

  1. Structures and spectroscopic characterization of calcium chloride-nicotinamide, -isonicotinamide, -picolinamide and praseodymium bromide-nicotinamide complexes.

    PubMed

    Xue, Junhui; Jiang, Ye; Li, Weihong; Yang, Limin; Xu, Yizhuang; Zhao, Guozhong; Zhang, Gaohui; Bu, Xiaoxia; Liu, Kexin; Chen, Jia'er; Wu, Jinguang

    2015-02-25

    The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca(2+), but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr(3+) to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca(2+). Pyridyl nitrogen and carbonyl oxygen of picolinamide are coordinated to Ca(2+) to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr(2+) or lanthanide ions, Ca(2+) is inclined to coordinate to carbonyl oxygen atoms of the ligands. PMID:25280333

  2. Fibre-end micro-lens system for endoscopic erbium-laser surgery applications

    NASA Astrophysics Data System (ADS)

    Heifer, D.; Frenz, M.; Romano, V.; Weber, H. P.

    1994-04-01

    A sapphire micro-lens system in combination with a zirconium-fluoride (ZrF4) fibre has been designed and constructed as a surgical tool for focusing Er:YAG-laser radiation. It both refocuses the laser radiation transmitted through a 350 µm core fibre to a spot diameter of 570 µm at a working distance of 7.6 mm, and protects the distal fibre end from damage. An accurate and uncomplicated visualization of the focus position of the erbium-laser beam is realized by coupling a HeNe aiming laser into the cladding of the fibre. In vitro cutting experiments reveal the high cutting precision with minimal thermal damage of the surrounding tissue and the high damage resistance of the system. It may render the use of the erbium laser possible in a wide range of endoscopic applications.

  3. Double Brillouin frequency spaced multiwavelength Brillouin-erbium fiber laser with 50 nm tuning range

    NASA Astrophysics Data System (ADS)

    Zhao, J. F.; Liao, T. Q.; Zhang, C.; Zhang, R. X.; Miao, C. Y.; Tong, Z. R.

    2012-09-01

    A 50 nm tuning range multiwavelength Brillouin-erbium fiber laser (MWBEFL) with double Brillouin frequency spacing is presented. Two separated gain blocks with symmetrical architecture, consisted by erbium-doped fiber amplifiers (EDFAs) and Brillouin gain media, are used to generate double Brillouin frequency spacing. The wider tuning range is realized by eliminating the self-lasing cavity modes existing in conventional MWBEFLs because of the absence of the physical mirrors at the ends of the linear cavity. The Brillouin pump (BP) is preamplified by the EDFA before entering the single-mode fiber (SMF), which leads to the reduction of threshold power and the generation enhancement of Brillouin Stokes (BS) signals. Four channels with 0.176 nm spacing are achieved at 2 mW BP power and 280 mW 980 nm pump power which can be tuned from 1525 to 1575 nm.

  4. Healing of bone in the rat following surgery with the erbium-YAG laser

    NASA Astrophysics Data System (ADS)

    Dickinson, Mark R.; Devlin, Hugh; El Montaser, Monsour A.; Sloan, Philip

    1996-12-01

    Background and objectives: the aim of this study was to examine the pattern of healing in rat calvarial defects prepared with the erbium-YAG laser, using the 'guided tissue regeneration' technique. Materials and method: PTFE membranes were placed over lased skull defects, and the skin wounds sutured. Rats were killed humanely at intervals after surgery, and the skulls processed for paraffin wax histology. A further group of mature rats were also killed humanely and the calvariae removed. Slots were prepared using the erbium-YAG laser and immediately examined under the environmental scanning electron microscope (ESEM) in hydrated conditions, which avoided drying artifacts. Results: An amorphous, mineral-rich carbon layer surrounds the lased bone defect, which in the in vivo experiments was seen as a basophilic zone which was resistant to resorption.

  5. Simulation of an erbium-doped chalcogenide micro-disk mid-infrared laser source.

    PubMed

    Al Tal, Faleh; Dimas, Clara; Hu, Juejun; Agarwal, Anu; Kimerling, Lionel C

    2011-06-20

    The feasibility of mid-infrared (MIR) lasing in erbium-doped gallium lanthanum sulfide (GLS) micro-disks was examined. Lasing condition at 4.5 µm signal using 800 nm pump source was simulated using rate equations, mode propagation and transfer matrix formulation. Cavity quality (Q) factors of 1.48 × 10(4) and 1.53 × 10(6) were assumed at the pump and signal wavelengths, respectively, based on state-of-the-art chalcogenide micro-disk resonator parameters. With an 80 µm disk diameter and an active erbium concentration of 2.8 × 10(20) cm(-3), lasing was shown to be possible with a maximum slope efficiency of 1.26 × 10(-4) and associated pump threshold of 0.5 mW. PMID:21716429

  6. High-performance air-stable n-type carbon nanotube transistors with erbium contacts.

    PubMed

    Shahrjerdi, Davood; Franklin, Aaron D; Oida, Satoshi; Ott, John A; Tulevski, George S; Haensch, Wilfried

    2013-09-24

    So far, realization of reproducible n-type carbon nanotube (CNT) transistors suitable for integrated digital applications has been a difficult task. In this work, hundreds of n-type CNT transistors from three different low work function metals-erbium, lanthanum, and yttrium-are studied and benchmarked against p-type devices with palladium contacts. The crucial role of metal type and deposition conditions is elucidated with respect to overall yield and performance of the n-type devices. It is found that high oxidation rates and sensitivity to deposition conditions are the major causes for the lower yield and large variation in performance of n-type CNT devices with low work function metal contacts. Considerable improvement in device yield is attained using erbium contacts evaporated at high deposition rates. Furthermore, the air-stability of our n-type transistors is studied in light of the extreme sensitivity of these metals to oxidation. PMID:24006886

  7. Reflection L-band erbium-doped fiber-amplifier-based fiber loop mirror

    NASA Astrophysics Data System (ADS)

    Meng, Hongyun; Liu, Songhao; Dong, Xiaoyi

    2005-01-01

    We constructed a reflection L-band erbium-doped fiber amplifier based on fiber loop mirror, which reflects the backward ASE to the EDF as a secondary pumping source. A gain of 30 dB increased 6 dB compared to the forward end-pumped EDFA has been achieved in the wavelength region from 1570 to 1603 nm. In order to improve the gain and NF further, we constructed a novel configuration for reflection L-band erbium-doped fiber amplifier via inserting a 980 nm LD in the input part. Adjusting the ratio of power of the two LDs, the gain and NF are greatly improved in different degree in the region from 1565 to 1615 nm. Compared to the configuration pumped by only 1480 nm LD with given power, the gain enhanced 1.5-9.9 dB and the NF decreases 1.3-9.4 dB.

  8. Erbium:YAG laser incision of urethral strictures: early clinical results

    NASA Astrophysics Data System (ADS)

    Munoz, John A.; Riemer, Jennifer D.; Hayes, Gary B.; Negus, Dan; Fried, Nathaniel M.

    2007-02-01

    Two cases involving Erbium:YAG laser incision of proximal bulbar urethral strictures are described. Erbium:YAG laser radiation with a wavelength of 2.94 μm, pulse energy of 10 mJ, and a pulse repetition rate of 15 Hz, was delivered through a 2-m-long, 250-μm-core sapphire optical fiber in contact with tissue. Total laser irradiation time was 5 min. The first patient suffering from a virgin urethral stricture was treated and is stricture-free. The second patient suffering from a recurrent urethral stricture required further treatment. This case report describes the first clinical application of the Er:YAG laser in urology.

  9. Space radiation effects on erbium-doped fiber devices: Sources, amplifiers and passive measurements

    SciTech Connect

    Williams, G.M. |; Friebele, E.J.

    1998-06-01

    Measurements have been made of the effect of {gamma}-irradiation on the performance of active erbium-doped fiber devices. These include the decrease in optical power of an erbium-doped fiber amplifier (EDFA) and a superluminescent source (SLS), and the shift in centroid wavelength of the SLS with exposure. Calculations have been performed to correlate these effects with the radiation-induced absorption measured passively. Excellent agreement was obtained for the radiation-induced power loss in the EDFA, and a good agreement was obtained for the SLS. However, the calculation underestimated the centroid wavelength shift in the SLS by a factor of {approximately}3. A model has been developed to extrapolate the results of passive loss measurements to the low dose rates typical of the natural space environment.

  10. Multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing.

    PubMed

    Shee, Y G; Al-Mansoori, M H; Ismail, A; Hitam, S; Mahdi, M A

    2011-01-31

    We demonstrate a multiwavelength Brillouin-erbium fiber laser with double-Brillouin-frequency spacing. The wider channel spacing is realized by circulating the odd-order Stokes signals in the Brillouin gain medium through a four-port circulator. The circulated odd-order Stokes signals are amplified by the Brillouin gain and thus produce even-order Stokes signals at the output. These signals are then amplified by erbium gain block to form a ring-cavity laser. Ten channels with 0.174 nm spacing that are generated at 0.5 mW Brillouin pump power and 150 mW pump power at 1480 nm can be tuned from 1556 nm to 1564 nm. The minimum optical signal-to-noise ratio of the generated output channels is 30 dB with maximum power fluctuations of ±0.5 dB. PMID:21368983

  11. Generation of efficient 20 GHz optical combs in a Brillouin-erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Parvizi, R.; Shahabuddin, N. S.; Ali, N. M.; Harun, S. W.; Emami, S. D.; Vaseghi, B.; Ahmad, H.

    2013-01-01

    A tunable multiwavelength Brillouin-erbium fiber laser is experimentally demonstrated with a double-Brillouin-frequency spacing. This double-frequency shifter is constructed by incorporating a four-port circulator to isolate and circulate the odd-Stokes signals through the 10 km long non-zero dispersion shifted fiber, which acts as a Brillouin gain medium. The output even-order Stokes signals are amplified in the erbium gain block formed in a ring cavity. Up to 15 lasing lines with a wavelength spacing of 0.173 nm have been achieved at a 980 nm pump power of 50 mW and a Brillouin pump of 3 dB m. The multiwavelength laser source exhibits a 10 nm tuning range from 1552 to 1562 nm with the optical signal-to-noise ratio of the desired output channels at around 34.5 dB.

  12. Biomimetic synthesis of chiral erbium-doped silver/peptide/silica core-shell nanoparticles (ESPN).

    PubMed

    Mantion, Alexandre; Graf, Philipp; Florea, Ileana; Haase, Andrea; Thünemann, Andreas F; Mašić, Admir; Ersen, Ovidiu; Rabu, Pierre; Meier, Wolfgang; Luch, Andreas; Taubert, Andreas

    2011-12-01

    Peptide-modified silver nanoparticles have been coated with an erbium-doped silica layer using a method inspired by silica biomineralization. Electron microscopy and small-angle X-ray scattering confirm the presence of an Ag/peptide core and silica shell. The erbium is present as small Er(2)O(3) particles in and on the silica shell. Raman, IR, UV-Vis, and circular dichroism spectroscopies show that the peptide is still present after shell formation and the nanoparticles conserve a chiral plasmon resonance. Magnetic measurements find a paramagnetic behavior. In vitro tests using a macrophage cell line model show that the resulting multicomponent nanoparticles have a low toxicity for macrophages, even on partial dissolution of the silica shell. PMID:22031101

  13. Modelling of micromachining of human tooth enamel by erbium laser radiation

    NASA Astrophysics Data System (ADS)

    Belikov, A. V.; Skrypnik, A. V.; Shatilova, K. V.

    2014-08-01

    We consider a 3D cellular model of human tooth enamel and a photomechanical cellular model of enamel ablation by erbium laser radiation, taking into account the structural peculiarities of enamel, energy distribution in the laser beam cross section and attenuation of laser energy in biological tissue. The surface area of the texture in enamel is calculated after its micromachining by erbium laser radiation. The influence of the surface area on the bond strength of enamel with dental filling materials is discussed. A good correlation between the computer simulation of the total work of adhesion and experimentally measured bond strength between the dental filling material and the tooth enamel after its micromachining by means of YAG : Er laser radiation is attained.

  14. Few-mode erbium-doped fiber amplifier with photonic lantern for pump spatial mode control.

    PubMed

    Lopez-Galmiche, G; Sanjabi Eznaveh, Z; Antonio-Lopez, J E; Velazquez Benitez, A M; Rodriguez Asomoza, J; Sanchez Mondragon, J J; Gonnet, C; Sillard, P; Li, G; Schülzgen, A; Okonkwo, C M; Amezcua Correa, R

    2016-06-01

    We demonstrate a few-mode erbium-doped fiber amplifier employing a mode-selective photonic lantern for controlling the modal content of the pump light. Amplification of six spatial modes in a 5 m long erbium-doped fiber to ∼6.2  dBm average power is obtained while maintaining high modal fidelity. Through mode-selective forward pumping of the two degenerate LP21 modes operating at 976 nm, differential modal gains of <1  dB between all modes and signal gains of ∼16  dB at 1550 nm are achieved. In addition, low differential modal gain for near-full C-band operation is demonstrated. PMID:27244421

  15. Invariant bandwidth of erbium in ZnO-PbO-tellurite glasses: Local probe/model

    SciTech Connect

    Ramamoorthy, Raj Kumar; Bhatnagar, Anil K.

    2014-04-24

    A series of [(70TeO{sub 2}−(30−x)ZnO−xPbO){sub 0.99}−(Er{sub 2}O{sub 3}){sub 0.01}; where x = 5, 10, 15 and 20] tellurite glasses, were prepared using the melt quenching technique. Crucial emission bandwidth of erbium at 1.5 μm has been derived and found to be the same for all the glasses, irrespective of PbO content. This identical bandwidth in all tellurite glasses is attributed to the presence of erbium in tellurium rich disordered environments. This result has been complemented through XANES spectra and the obtained invariant first shell of 6.5 oxygen atoms, confirm the unchanged environment in these glasses for all PbO content.

  16. Opportunities for Low Cost Processing of Erbium 8-Quinolinolates for Active Integrated Photonic Applications.

    PubMed

    Penna, Stefano; Mattiello, Leonardo; Di Bartolo, Silvia; Pizzoleo, Angelo; Attanasio, Vincenzo; Beleffi, Giorgio Maria Tosi; Otomo, Akira

    2016-04-01

    Erbium-doped organic emitters are promising active materials for Photonic Integrated Circuits (PICs) due to their emission shown at 1550 nm combined to the potential low cost processing. In particular, Erbium Quinoline (ErQ) gained a strong interest in the last decade for the good emission efficiency. This contribution reports the results derived from the application of ErQ as active core material within a buried optical waveguide, following the development of a purposed optical process to control the refractive index of ErQ and then to define a patterned structure from a single thin film deposition step. The reported results show the potential of Er-doped organic materials for low cost processing and application to planar PICs. PMID:27451632

  17. Modelling of micromachining of human tooth enamel by erbium laser radiation

    SciTech Connect

    Belikov, A V; Skrypnik, A V; Shatilova, K V

    2014-08-31

    We consider a 3D cellular model of human tooth enamel and a photomechanical cellular model of enamel ablation by erbium laser radiation, taking into account the structural peculiarities of enamel, energy distribution in the laser beam cross section and attenuation of laser energy in biological tissue. The surface area of the texture in enamel is calculated after its micromachining by erbium laser radiation. The influence of the surface area on the bond strength of enamel with dental filling materials is discussed. A good correlation between the computer simulation of the total work of adhesion and experimentally measured bond strength between the dental filling material and the tooth enamel after its micromachining by means of YAG : Er laser radiation is attained. (laser biophotonics)

  18. 1.54 micron Emission from Erbium implanted GaN for Photonic Applications

    NASA Technical Reports Server (NTRS)

    Thaik, Myo; Hommerich, U.; Schwartz, R. N.; Wilson, R. G.; Zavada, J. M.

    1998-01-01

    The development of efficient and compact light sources operating at 1.54 micron is of enormous importance for the advancement of new optical communication systems. Erbium (1%) doped fiber amplifiers (EDFA's) or semiconductor lasers are currently being employed as near infrared light sources. Both devices, however, have inherent limitations due to their mode of operation. EDFA's employ an elaborate optical pumping scheme, whereas diode lasers have a strongly temperature dependent lasing wavelength. Novel light emitters based on erbium doped III-V semiconductors could overcome these limitations. Er doped semiconductors combine the convenience of electrical excitation with the excellent luminescence properties of Er(3+) ions. Electrically pumped, compact, and temperature stable optoelectronic devices are envisioned from this new class of luminescent materials. In this paper we discuss the potential of Er doped GaN for optoelectronic applications based on temperature dependent photoluminescence excitation studies.

  19. A Room-Temperature Multiwavelength Erbium-Doped Fibre Laser by Exploiting Polarization Hole Burning

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Xiong, Ling-Yun; Dou, Qing-Ying; Li, Yao; Yu, Ling; Liu, Yan-Ge; Liu, Li-Hui; Yuan, Shu-Zhong; Kai, Gui-Yun; Dong, Xiao-Yi

    2005-01-01

    Multiwavelength operation of a linear cavity erbium-doped fibre laser (EDFL) is proposed and demonstrated. A 3-dB fibre loop mirror and a high birefringence (HiBi) fibre loop mirror are utilized as the cavity reflectors. By utilizing the wavelength-dependent polarization rotation induced by the HiBi fibre loop mirror and by using a fibre polarizer to control the intracavity polarization state, the polarization states of different wavelengths are diversified. Therefore, the polarization hole burning (PHB) effect has been greatly enhanced and the homogeneous broadening of erbium-doped fibre is suppressed to a large extent. By simply tuning a polarization controller, we experimentally obtained simultaneous lasing of four and five wavelengths with wavelength spacing of ~1.8 nm and less than 2 nm at room temperature, respectively. The repeated scans show that all of these lasers have good stability.

  20. Erbium-doped spiral amplifiers with 20 dB of net gain on silicon.

    PubMed

    Vázquez-Córdova, Sergio A; Dijkstra, Meindert; Bernhardi, Edward H; Ay, Feridun; Wörhoff, Kerstin; Herek, Jennifer L; García-Blanco, Sonia M; Pollnau, Markus

    2014-10-20

    Spiral-waveguide amplifiers in erbium-doped aluminum oxide on a silicon wafer are fabricated and characterized. Spirals of several lengths and four different erbium concentrations are studied experimentally and theoretically. A maximum internal net gain of 20 dB in the small-signal-gain regime is measured at the peak emission wavelength of 1532 nm for two sample configurations with waveguide lengths of 12.9 cm and 24.4 cm and concentrations of 1.92 × 10(20) cm(-3) and 0.95 × 10(20) cm(-3), respectively. The noise figures of these samples are reported. Gain saturation as a result of increasing signal power and the temperature dependence of gain are studied. PMID:25401633

  1. Coupling erbium spins to a three-dimensional superconducting cavity at zero magnetic field

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Hui; Fernandez-Gonzalvo, Xavier; Longdell, Jevon J.

    2016-08-01

    We experimentally demonstrate the coupling at zero magnetic field of an isotopically pure erbium-doped yttrium orthosilicate crystal (167Er:YSO ) to a three-dimensional superconducting cavity with a Q factor of 105. A tunable loop-gap resonator is used and its resonance frequency is tuned to observe the hyperfine transitions of the erbium sample. The observed spectrum differs from what is predicted by the published spin Hamiltonian parameters. The narrow cavity linewidth also enables the observation of asymmetric line shapes for these hyperfine transitions. Such a broadly tunable superconducting cavity (from 1.6 to 4.0 GHz in the current design) is a promising device for building hybrid quantum systems.

  2. Theoretical explanation of enhanced low dose rate sensitivity in erbium-doped optical fibers.

    PubMed

    Gilard, Olivier; Thomas, Jérémie; Troussellier, Laurent; Myara, Mikhael; Signoret, Philippe; Burov, Ekaterina; Sotom, Michel

    2012-05-01

    A new theoretical framework is proposed to explain the dose and dose-rate dependence of radiation-induced absorption in optical fibers. A first-order dispersive kinetics model is used to simulate the growth of the density of color centers during an irradiation. This model succeeds in explaining the enhanced low dose rate sensitivity observed in certain kinds of erbium-doped optical fiber and provides some insight into the physical reasons behind this sensitivity. PMID:22614396

  3. Soliton propagation in an erbium-doped fiber with and without a continuous wave background

    NASA Astrophysics Data System (ADS)

    Ganapathy, R.; Kuriakose, V. C.; Porsezian, K.

    2003-12-01

    Considering ultrashort pulse propagation in a nonlinear resonant fiber governed by Hirota-Maxwell Bloch equations, the soliton interaction in an erbium-doped fiber system associated with higher-order dispersion, self-steepening, and self-induced transparency effects is studied for the case when the fiber is driven with and without a constant pumping source. Using auto-Bäcklund-transformation, one- and two-soliton solutions are generated. The significance of the results is discussed in detail.

  4. Synthesis and characterization of erbium-doped YAlO3 phosphor.

    PubMed

    Baig, Huma Nazli; Saluja, Jagjeet Kaur; Dhoble, S J

    2016-03-01

    In the yttrium aluminium system, the YAlO3 phosphor is a prominent host because of the yttrium aluminium ratio (1:1). Phosphor was synthesized by the solid-state reaction method at variable concentrations of erbium (0.1-2.5 mol%). This method is suitable for large-scale production and is a less time-consuming method when compared with the soft synthesis method. The prepared sample was characterized by X-ray diffraction technique and the crystallite size was calculated by Scherer's formula. Vibrational and bending analysis of prepared phosphor for optimized concentration of erbium ion is described based on the Fourier transform infrared spectroscopic technique. The photoluminescence (PL) emission spectra of prepared phosphor for variable concentrations of erbium ion were recorded and the excitation spectrum was found to be at 291 nm with three shoulder peaks at 305, 270 and 242 nm. For 291 nm excitation, the emission spectrum was found at 546 nm and 552 nm. PL intensity increased with increasing concentrations of erbium and after 2 mol% emission intensity decreased due to concentration quenching. Spectrophotometric determination of YAlO3:Er(3+) is described by CIE co-ordinates and shows an intense emission in the green region such that the prepared phosphor can act as a single host for green light emission. Thermoluminescence glow curve analysis of the YAlO3:Er(3+) phosphor was recorded for different ultraviolet (UV) light exposures and gamma exposure. Different gamma doses 0.5-2 kGy show a linear response. Kinetic parameters were calculated by the peak shape method. PMID:26455914

  5. Pulsed erbium fiber laser with an acetylene-filled photonic crystal fiber for saturable absorption.

    PubMed

    Marty, Patrick Thomas; Morel, Jacques; Feurer, Thomas

    2011-09-15

    We investigate the dynamics of an erbium-doped fiber ring laser that is equipped with an intracavity hollow core photonic crystal fiber gas cell. The cell is filled with acetylene as a saturable absorber. We observe cw operation at low pressures, Q switching at intermediate pressure levels, and mode locking at high pressures applied. Moreover, we show that the transition from the cw to the pulsed mode may be exploited for sensitive gas detection. PMID:21931393

  6. Dynamic Fano-like resonances in erbium-doped whispering-gallery-mode microresonators

    SciTech Connect

    Lei, Fuchuan; Peng, Bo; Özdemir, Şahin Kaya Yang, Lan; Long, Gui Lu

    2014-09-08

    We report Fano-like asymmetric resonances modulated by optical gain in a whispering-gallery-mode resonator fabricated from erbium-doped silica. A time-dependent gain profile leads to dynamically varying sharp asymmetric resonances with features similar to Fano resonances. Depending on the scan speed of the frequency of the probe laser and the pump-probe power ratio, transmission spectra of the active microcavity exhibit a resonance dip, a resonance peak, or a Fano-like resonance.

  7. Lanthanide Recognition: an Asymetric Erbium Microsensor Based on a Hydrazone Derivative

    PubMed Central

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Larijani, Bagher; Norouzi, Parviz; Riahi, Siavash; Mirnaghi, Fatemeh Sadat

    2007-01-01

    N'-(2-hydroxy-1,2-diphenylethylidene)benzohydrazide (HDB) was found to have a very selective and sensitive behavior towards erbium(III) ions, in comparison to thirteen lanthanide ions, inner transition and representative metal ions and was hence used as a neutral ion carrier in construction of an Er(III) microelectrode. Theoretical calculations and conductance studies of HDB to erbium and some other metal ions were carried out and confirmed selectivity toward Er(III) ions. The best performance was obtained with a membrane contain 3% potassium tetrakis(p-chlorophenyl)borate (KTpClPB) as an anionic additive, 72% dibutyl phthalate (DBP) as solvent mediator, 5% HDB, and 20% poly(vinyl chloride) (PVC). The proposed Er(III) microelectrode exhibits a near Nernstian response of 17.5±0.5 mV per decade of erbium activity, and a very wide linear range 1.0×10-3-3.0×10-10 M. It can work well in the pH range of 3.0-9.0. The lower detection limit (LDL) of the microelectrode was calculated to be 2.0×10-10 M.

  8. Effect of praseodymium on the electrical resistance of YВа2Сu3О7-δ single crystals

    NASA Astrophysics Data System (ADS)

    Vovk, R. V.; Vovk, N. R.; Khadzhai, G. Ya.; Goulatis, I. L.; Chroneos, A.

    2014-07-01

    The electrical resistivity in the ab-plane of the Y1-yPryВа2Сu3О7-δ single crystals with high degree of perfection in the interval of Тc - 300 K was investigated. The increasing of praseodymium content leads to the reduction of the critical temperature (Tc) from 92 to 30 K. The experimental results can be approximated by the expression, taking into account the scattering of electrons by phonons, defects, the fluctuation conductivity in the 3D Aslamazov-Larkin model, as well as the transition to a "semiconductor" type behavior of the resistivity at the high praseodymium concentrations. The concentration dependences of all fitting parameters indicate a structural transition in the region 0.35≤у≤0.43. In particular, the Debye temperature changes in this range from 350 to 550 K, and the transverse coherence length passes through a maximum ξС(0)≈5 Å. The concentration dependence of the critical temperature testifies the d-pairing of the BCS model.

  9. Kidney stone ablation times and peak saline temperatures during Holmium:YAG and Thulium fiber laser lithotripsy, in vitro, in a ureteral model

    NASA Astrophysics Data System (ADS)

    Hardy, Luke A.; Wilson, Christopher R.; Irby, Pierce B.; Fried, Nathaniel M.

    2015-02-01

    Using a validated in vitro ureter model for laser lithotripsy, the performance of an experimental Thulium fiber laser (TFL) was studied and compared to clinical gold standard Holmium:YAG laser. The Holmium laser (λ = 2120 nm) was operated with standard parameters of 600 mJ, 350 μs, 6 Hz, and 270-μm-core optical fiber. TFL (λ = 1908 nm) was operated with 35 mJ, 500 μs, 150-500 Hz, and 100-μm-core fiber. Urinary stones (60% calcium oxalate monohydrate / 40% calcium phosphate), of uniform mass and diameter (4-5 mm) were laser ablated with fibers through a flexible video-ureteroscope under saline irrigation with flow rates of 22.7 ml/min and 13.7 ml/min for the TFL and Holmium laser, respectively. The temperature 3 mm from tube's center and 1 mm above mesh sieve was measured by a thermocouple and recorded during experiments. Total laser and operation times were recorded once all stone fragments passed through a 1.5-mm sieve. Holmium laser time measured 167 +/- 41 s (n = 12). TFL times measured 111 +/- 49 s, 39 +/- 11 s, and 23 +/- 4 s, for pulse rates of 150, 300, and 500 Hz (n = 12 each). Mean peak saline irrigation temperatures reached 24 +/- 1 °C for Holmium, and 33 +/- 3 °C, 33 +/- 7 °C, and 39 +/- 6 °C, for TFL at pulse rates of 150, 300, and 500 Hz. To avoid thermal buildup and provide a sufficient safety margin, TFL lithotripsy should be performed with pulse rates below 500 Hz and/or increased saline irrigation rates. The TFL rapidly fragmented kidney stones due in part to its high pulse rate, high power density, high average power, and reduced stone retropulsion, and may provide a clinical alternative to the conventional Holmium laser for lithotripsy.

  10. Solvent extraction of holmium and yttrium with bis(2-ethylhexyl)phosphoric acid

    SciTech Connect

    Yoshizuka, K.; Sakamoto, Y.; Baba, Y.; Inoue, K. ); Nakashio, F. )

    1992-05-01

    This paper discusses a kinetic study on the solvent extraction of holmium(III) and yttrium(III) with bis(2-ethylhexyl) phosphoric acid (D2EHPA) from nitrate media conducted at 303 K using a hollow fiber membrane extractor. Also studied were the distribution equilibria of these metals and interfacial adsorption equilibria of D2EHPA and its metal complexes between the organic and aqueous phases. It was found that the metals (M{sup 3+}) were extracted with D2EHPA (HR) ad MR{sub 3} {center dot} 3HR into the organic phase, and the extraction equilibrium constants were evaluated. Furthermore, it was established that dimeric D2EHPA can be adsorbed at the interface between the organic and aqueous phases, while the interfacial activities of D2EHPA-metal complexes were negligibly small. The apparent orders 2, 1, and 2 of the permeabilities for the extraction of both metals were found with respect to the pH of the aqueous solution and the concentrations of the metal ion and dimeric D2EHPA, while the orders 1, 1, and {minus}1 of the permeabilities for the stripping of both metals were found with respect to the hydrogen ion activity and the concentrations of the metal complex and dimeric D2EHPA, respectively. The diffusional effects were reasonably explained by the diffusion model accompanied by an interfacial reaction, taking into account the velocity distributions of the aqueous and organic phases through the inner and outer sides of a hollow fiber.

  11. Laboratory investigation of the efficacy of holmium:YAG laser irradiation in removing intracanal debris

    NASA Astrophysics Data System (ADS)

    Nuebler-Moritz, Michael; Gutknecht, Norbert; Sailer, Hermann F.; Hering, Peter; Prettl, Wilhelm

    1997-05-01

    Current endodontic therapy involves debridement and disinfection of the root canal by means of mechanical instrumentation and chemical irrigation. However, several studies have shown that these techniques fail to achieve complete cleansing. Recently, lasers have been suggested for use within root canals. This study was conducted to determine the efficacy of Holmium:YAG laser irradiation in removing intracanal debris and smear layer. Root canal surfaces of freshly-extracted human teeth were exposed to pulsed Ho:YAG laser radiation. Subsequently, laser induced structural changes were investigated using scanning electron microscopy. Temperature measurements during irradiation were performed by means of thermocouples. The result of this survey give a preliminary indication of the ability of the Ho:YAG laser to improve current endodontic treatment survey give a preliminary indication of the ability of the Ho:YAG laser to improve current endodontic treatment modalities. However, limitations exist with regard to circumscribed and well-quantified irradiation of root canal surfaces, due to the lack of perpendicular delivery of the laser beam. Additional studies will be required to develop suitable optical transmission systems, in order to achieve complete cleansing and to avoid damage to the periradicular tissues, respectively.

  12. Changes in corneal collagen induced by holmium:YAG laser irradiation

    NASA Astrophysics Data System (ADS)

    Timberlake, George T.; Reinke, Martin H.; Miller, Alvin

    1996-05-01

    Holmium:YAG laser thermokeratoplasty corrects hyperopia (farsightedness) by producing small areas of corneal collagen shrinkage that cause the central cornea to bulge outward, increasing optical power. Collagen shrinkage is probably caused by laser-heated corneal water, but details of the shrinkage mechanism are not known. We investigated the shrinkage mechanism by measuring changes in corneal ultrastructure, surface shrinkage, water content, and strength following Ho:YAG laser exposures. Morphological changes in collagen were documented by measurements from electron micrographs. Corneal adhesive strength was determined by measuring tearing force in a plane parallel to the corneal surface. Laser-induced water loss was measured by weighing corneal samples before and after exposure. Corneal surface shrinkage was assessed by photographing the movement of particles on the cornea. Lasered collagen fibrils increased in diameter, lost their orderly arrangement, and appeared `frayed.' The corneal surface contracted toward lasered areas with a maximal shift of approximately 190 micrometers , more than could be explained by a model based on collagen fibril changes. Water loss plays a minor role in corneal shrinkage since corneal samples lost about only about 1.4% of their weight after massive laser exposure. Despite marked changes in collagen structure, corneal adhesive force was unchanged.

  13. Effectiveness and Safety of Ureteroscopic Holmium Laser Lithotripsy for Upper Urinary Tract Calculi in Elderly Patients.

    PubMed

    Yoshioka, Takashi; Otsuki, Hideo; Uehara, Shinya; Shimizu, Toshihiro; Murao, Wataru; Fujio, Koji; Fujio, Kei; Wada, Koichiro; Araki, Motoo; Nasu, Yasutomo

    2016-06-01

    Upper urinary tract calculi are common; however, there is no recommended treatment selection for elderly patients. Ureteroscopic holmium laser lithotripsy (URS lithotripsy) is minimally invasive, and it provides a high stone-free rate (SFR) treatment for upper urinary tract calculi. Here, we retrospectively evaluated the surgical outcomes of URS lithotripsy after dividing the 189 cases into 3 groups by patient age: the '<65 group' (<65 years old, n=108), the '65-74 group' (65-74 years old, n=42), and the ' 75 group' ( 75 years old, n=39). The patients' characteristics, stone status, and perioperative outcomes were assessed. The 65-74 group and the 75 group had a significantly higher prevalence of hypertension compared to the<65 group. Compared to the<65 group, the 65-74 group had a significantly higher prevalence of hyperlipidemia, and the 75 group had significantly higher the American Society of Anesthesiologists (ASA) scores. Despite these preoperative risk factors, SFR and postoperative pyelonephritis in the 65-74 group and the 75 group were similar to those of the<65 group. In conclusion, URS lithotripsy is the preferred treatment for upper urinary tract calculi, even for elderly patients who have multiple preoperative risk factors. PMID:27339204

  14. An Improved Morcellation Procedure for Holmium Laser Enucleation of the Prostate

    PubMed Central

    Chen, Qi; Chen, Yan-Bo; Zheng, Da-Chao; Cai, Zhi-Kang; Li, Wen-Ji; Zhou, Juan

    2012-01-01

    Abstract Purpose We modified the conventional morcellation procedure for holmium laser enucleation of the prostate (HoLEP), and its outcomes are presented in this article. Materials and Methods As 395 patients were included, the conventional morcellation procedure was performed in the first 100 cases (group 1, cases 1–100), and an improved procedure was used in the last 100 cases (group 2, cases 296–395). The improved morcellation process has three steps to execute. The morcellation time, collected tissue weight, morcellation rate, and associated complications were recorded. Results The tissue-resected weight was similar between group 1 (60.7±33.9 g) and group 2 (62.4±36.8 g). The mean morcellation time in group 1 was greater than that in group 2 (11.3±7.1 and 8.3±4.1 minutes, respectively), and the mean morcellation rate was better in group 2 than in group 1 (5.75±1.7 g/minutes in group 1 v 7.3±1.1 g/minutes in group 2). Complications, such as bladder injury, were similar in both groups. Conclusion The improved morcellation procedure described in this article can be used in various situations of suction and can be performed in a more fluent manner and with better efficiency. PMID:22788738

  15. Efficacy of Holmium Laser Enucleation of the Prostate Based on Patient Preoperative Characteristics

    PubMed Central

    Suh, Yoon Seok; Kim, Tae Heon; Sung, Hyun Hwan; Jeong, Jeongyun

    2015-01-01

    Purpose: To evaluate the efficacy of holmium laser enucleation of the prostate (HoLEP) in relation to prostate size and urodynamic parameters, including bladder outlet obstruction index (BOOI), presence of detrusor overactivity, and detrusor contractility, and to investigate factors predictive of HoLEP success. Methods: This retrospective analysis of prospective data included 174 consecutive patients treated with HoLEP at Samsung Medical Center from 2009 to 2013. Prostate-specific antigen, prostate size, urodynamic parameters, and International Prostate Symptom Score (IPSS)/quality of life (QoL) were evaluated preoperatively, while prostate-specific antigen, uroflowmetry/postvoid residual (PVR) urine, and IPSS were measured six months after HoLEP. Two definitions of treatment success were established based on the following three variables: IPSS, maximum flow rate (Qmax), and QoL index. Factors predictive of HoLEP success were identified using multiple logistic regression analysis. Results: IPSS/QoL, Qmax, and PVR improved significantly following HoLEP. Improvements in IPSS and PVR were more significant in the BOOI≥40 group compared to the BOOI<40 group, with overall success rates of 93.7% and 73.6%, respectively. Thus, the BOOI≥40 group had a significantly higher success rate, and BOOI≥40 was a significant predictor of HoLEP success based on the multivariate analyses. Conclusions: We found good surgical outcomes after HoLEP, and specifically patients with a higher BOOI had a greater chance of surgical success. PMID:26739183

  16. Electron transfer behavior and water photodecomposition ability of calcined material from a cerium-S-phenylene-O-holmium-O-phenylene-S hybrid copolymer.

    PubMed

    Matsui, Hideo; Otsuki, Keigo; Yamada, Hiroyoshi; Kawahara, Tetsuro; Yoshihara, Masakuni

    2006-05-15

    Calcination of a cerium-S-phenylene-O-holmium-O-phenylene-S hybrid copolymer under a vacuum gave cerium oxide-carbon cluster-holmium oxide composite material. The material calcined at 600 degrees C loaded with Pt particles could decompose water to H2 and O2 with a H2/O2 ratio of 2 under visible light irradiation. ESR spectral examinations of the calcined materials revealed the possibility of a two-step electron transfer in the process of CeO2 --> carbon cluster --> Ho2O3 --> Pt with an oxidation site at CeO2 particles and a reduction site at Pt particles. PMID:16313919

  17. Sintering effects on structure, morphology, and electrical properties of sol-gel synthesized, nano-crystalline erbium oxide

    NASA Astrophysics Data System (ADS)

    Bakhsh, Allah; Maqsood, Asghari

    2012-12-01

    The nano-crystalline erbium oxide powder was synthesized through the sol-gel technique. The effect of sintering temperature from 250°C to 1400°C on structure, morphology, and electrical properties was studied. The results were compared with the microcrystalline erbium oxide purchased from the market. The synthesized erbium oxide showed fiber like nanostructures. Dielectric properties at different sintering temperatures were measured in the frequency range 100 Hz to 5MHz. The synthesized erbium oxide had the highest dielectric constant at 650°C. The behavior of the dissipation factor tan δ for sol-gel synthesized material was distinct from that of the purchased material; it was higher at low frequencies and then decreased with the increase in frequency. The synthesized material sintered at different temperatures exhibited a similar sort of frequency-dependent response for permittivity (ɛ) and resistivity ( ρ). This was in accordance with Koop's theory of dielectrics. For the microcrystalline material, frequency dependence of permittivity and resistivity was not uniform. The results showed that sol-gel synthesized erbium oxide could be a good candidate for high-k applications.

  18. Optimizing the pumping configuration for the power scaling of in-band pumped erbium doped fiber amplifiers.

    PubMed

    Lim, Ee-Leong; Alam, Shaif-ul; Richardson, David J

    2012-06-18

    A highly efficient (~80%), high power (18.45 W) in-band, core pumped erbium/ytterbium co-doped fiber laser is demonstrated. To the best of our knowledge, this is the highest reported efficiency from an in-band pumped 1.5 µm fiber laser operating in the tens of watts regime. Using a fitted simulation model, we show that the significantly sub-quantum limit conversion efficiency of in-band pumped erbium doped fiber amplifiers observed experimentally can be explained by concentration quenching. We then numerically study and experimentally validate the optimum pumping configuration for power scaling of in-band, cladding pumped erbium doped fiber amplifiers. Our simulation results indicate that a ~77% power conversion efficiency with high output power should be possible through cladding pumping of current commercially available pure Erbium doped active fibers providing the loss experienced by the cladding guided 1535 nm pump due to the coating absorption can be reduced to an acceptable level by better coating material choice. The power conversion efficiency has the potential to exceed 90% if concentration quenching of erbium ions can be reduced via improvements in fiber design and fabrication. PMID:22714454

  19. Synthesis and characterization of erbium-doped SiO2 nanoparticles fabricated by using reverse micelle and sol-gel processing

    NASA Astrophysics Data System (ADS)

    Park, Hoyyul; Bae, Dong-Sik

    2012-11-01

    Erbium-doped SiO2 nanoparticles have been synthesized using a reverse micelle technique combined with metal-alkoxide hydrolysis and condensation. The sizes and the morphologies of the erbium-doped SiO2 nanoparticles could be changed by varying the molar ratio of water to surfactant. The sizes and the morphologies of the erbium-doped SiO2 nanoparticles were examined by using a transmission electron microscope. The average size of synthesized erbium-doped SiO2 nanoparticles was approximately 20-25 nm and that of the erbium particles was 3-5 nm. The effects of the synthesis parameters, such as the molar ratio of water to surfactant, are discussed.

  20. Surface segregation effects of erbium in GaAs growth and their implications for optical devices containing ErAs nanostructures

    SciTech Connect

    Crook, Adam M.; Nair, Hari P.; Bank, Seth R.

    2011-03-21

    We report on the integration of semimetallic ErAs nanoparticles with high optical quality GaAs-based semiconductors, grown by molecular beam epitaxy. Secondary ion mass spectrometry and photoluminescence measurements provide evidence of surface segregation and incorporation of erbium into layers grown with the erbium cell hot, despite the closed erbium source shutter. We establish the existence of a critical areal density of the surface erbium layer, below which the formation of ErAs precipitates is suppressed. Based upon these findings, we demonstrate a method for overgrowing ErAs nanoparticles with III-V layers of high optical quality, using subsurface ErAs nanoparticles as a sink to deplete the surface erbium concentration. This approach provides a path toward realizing optical devices based on plasmonic effects in an epitaxially-compatible semimetal/semiconductor system.

  1. Probabilities for nonradiative intermultiplet transitions in the holmium ion in lithium-yttrium double fluoride crystals and stimulated emission

    SciTech Connect

    Tkachuk, A.M.; Khilko, A.V.; Petrov, M.V.

    1985-02-01

    Nonradiative transition probabilities have been studied as functions of the energy difference between the closest-lying multiplets of the Ho/sup 3 +/ ion in the LiYF/sub 4/ crystal. The efficiencies of emission from terms of the holmium ion have been determined. The cross sections for stimulated emission for emission lines corresponding to the transition /sup 5/S/sub 2/ ..-->.. /sup 5/I/sub 7/ have also been determined. Some characteristics of the stimulated emission of LiYF/sub 4/:Ho/sup 3 +/ crystals are reported for several wavelengths in the 0.75--3.9-..mu..m spectral interval.

  2. Bipolar, Monopolar, Photovaporization of the Prostate, or Holmium Laser Enucleation of the Prostate: How to Choose What's Best?

    PubMed

    Cornu, Jean-Nicolas

    2016-08-01

    Endoscopic management of benign prostatic obstruction is based on resection, vaporization, or enucleation. Enucleation provides the best efficacy and long-term outcome. Lasers have advantages in patients at high risk of bleeding. Holmium enucleation is the best evaluated technique, but has a steep learning curve. Greenlight photovaporization is a safe alternative to transurethral resection of the prostate (TURP) in prostates of less than 100 mL, especially in patients at high risk of bleeding. Bipolar devices can be used for resection, vaporization, and enucleation and provides efficacy results similar to TURP in the short term with better safety. PMID:27476130

  3. Sub-100 fs passively mode-locked holmium-doped fiber oscillator operating at 2.06 μm

    NASA Astrophysics Data System (ADS)

    Li, Peng; Ruehl, Axel; Grosse-Wortmann, Uwe; Hartl, Ingmar

    2015-03-01

    We demonstrate a simple and compact Holmium-doped fiber (HDF) femtosecond oscillator with 35 MHz repetition rate. The oscillator is pumped by a Tm-doped fiber laser. A dispersion compensating fiber was utilized to set the net-intracavity dispersion to zero at 2.06 μm. The output pulses had an maximum average power of 40 mW and 160 fs FWHM pulse duration. To further shorten the pulse duration, we implemented a nonlinear compressor consisting of a solid core highly nonlinear fiber (HNLF) for SPM broadening and single mode fiber (SMF) for pulse compression. Sub-100 fs pulses were achieved.

  4. Specific features of the mechanisms of excitation of erbium photoluminescence in epitaxial Si:Er/Si structures

    SciTech Connect

    Yablonskiy, A. N. Andreev, B. A.; Krasilnikova, L. V.; Kryzhkov, D. I.; Kuznetsov, V. P.; Krasilnik, Z. F.

    2010-11-15

    The excitation spectra and kinetics of erbium photoluminescence and silicon interband photoluminescence in Si:Er/Si structures under conditions of high-intensity pulse optical excitation are studied. It is shown that, in the interband photoluminescence spectra of the Si:Er/Si structures, both the luminescence of free excitons and the emission associated with the electron-hole plasma can be observed, depending on the excitation power and wavelength. It is found that the formation of a peak in the erbium photoluminescence excitation spectra at high pumping powers correlates with the Mott transition from the exciton gas to the electron-hole plasma. It is demonstrated that, in the Si:Er/Si structures, the characteristic rise times of erbium photoluminescence substantially depend on the concentration of charge carriers.

  5. Holmium Laser Enucleation of Prostate for Benign Prostatic Hyperplasia: Seoul National University Hospital Experience

    PubMed Central

    Bae, Jungbum; Choo, Minsoo; Park, Ji Hyun; Oh, Jin Kyu; Paick, Jae-Seung

    2011-01-01

    Purpose The objective of this study was to report the experience acquired at the Seoul National University Hospital with Holmium Laser Enucleation of Prostate (HoLEP), combined with mechanical morcellation for symptomatic benign prostatic hyperplasia (BPH). Methods A retrospective review was performed on the clinical data of 309 consecutive patients who underwent HoLEP at our institution between July 2008 and June 2010. All patients were evaluated preoperatively for prostate volume by transrectal ultrasound, maximum urinary flow rate (Qmax), International Prostate Symptoms Score (IPSS) and quality of life (QoL) score. Peri- and postoperative parameters were evaluated and patients were followed-up at 1-, 3-, 6-, and 12- months with the aforementioned investigations. Results The patients' mean age was 68.3 (±6.5) years and mean prostate volume was 55.6 (±23.6) mL. Mean enucleation time was 56.2 (±25.1) minutes, mean morcellation time was 11.3 (±9.5) minutes, and the mean resected weight of the prostate was 20.8 (±16.9) g. The mean catheter indwelling period was 1.9 (±1.7) days and mean hospital stay was 2.9 (±1.5) days. Significant improvement was noted in Qmax, IPSS, and QoL at the 1-year follow-up compared with baseline (P<0.01). At 1 month 17.2% of patients complained of irritative urinary symptoms, which were typically self-limiting within 3 months. Transient stress incontinence was reported in 15.2% of patients. No patient experienced persistent obstructive symptoms that required reoperation. Conclusions Our study showed that HoLEP is a safe and effective therapeutic modality for BPH. PMID:21468284

  6. Risk Factors for Transient Urinary Incontinence after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Nam, Jong Kil; Kim, Hyeon Woo; Lee, Dong Hoon; Han, Ji-Yeon; Lee, Jeong Zoo

    2015-01-01

    Purpose To investigate the factors associated with the occurrence of and recovery from transient urinary incontinence (TUI) after holmium laser enucleation of the prostate (HoLEP). Materials and Methods From March 2009 to December 2012, 391 consecutive patients treated with HoLEP for benign prostatic hyperplasia were enrolled. Information regarding age, prostate volume, International Prostate Symptom Score, Overactive Bladder Symptom Score, peak urinary flow rate, postvoid residual urine, and operation time was collected. TUI was defined as a patient complaint of urine leakage, regardless of type. Logistic regression was used to investigate the factors associated with the occurrence of TUI, and the Kaplan-Meier test was used to analyze the TUI recovery period. Results TUI after HoLEP occurred in 65 patients (16.6%), 52 patients of whom (80.0%) showed recovery within three months. Stress and urge urinary incontinence and postvoid dribbling occurred in 16 patients (4.1%), 29 patients (7.4%), and 33 patients (8.4%), respectively. Age (odds ratio [OR]=3.494; 95% confidence interval [CI]=1.565~7.803; p=0.002) and total operation time (OR=3.849; 95% CI=1.613~9.185; p=0.002) were factors that significantly affected the occurrence of TUI. Conclusions TUI, defined as any type of urine leakage, occurred after HoLEP in some patients, most of whom recovered within three months. Stress urinary incontinence occurred in only 4% of patients after HoLEP. Age and total operation time were associated with the occurrence of postoperative TUI. PMID:26331125

  7. Salvage Holmium laser enucleation of prostate to treat residual benign prostatic hyperplasia

    PubMed Central

    Oh, Jin Kyu; Bae, Jungbum; Jeong, Chang Wook; Paick, Jae-Seung; Oh, Seung-June

    2014-01-01

    Introduction: The Holmium laser enucleation of the prostate (HoLEP) technique to remove residual adenoma has not been reported. Salvage HoLEP enables anatomical enucleation of residual adenoma in patients who have previously undergone surgical treatment. We describe not only anatomical insights into the frequent location of adenoma recurrence, but also the feasibility of the salvage HoLEP technique. Methods: We retrospectively reviewed a database containing HoLEP video records for 35 patients out of a total of 535 individuals on whom HoLEP was performed by 2 surgeons (SJO & JSP) between July 2008 and June 2011. Group 1 consisted of patients who underwent salvage HoLEP due to recurring adenoma and Group 2 of patients who underwent HoLEP as an initially surgical management to treat benign prostate hyperplasia (BPH). We compared the dataset of pre-, intra- and postoperative parameters between Groups 1 and 2. Results: In the analysis of the video records of Group 1 (n = 35), there was significant remnant tissue around the verumontanum and the lateral lobes were also incompletely removed by previous conventional procedures. When we compared pre-, intra- and postoperative parameters between the 2 groups, there were no significant differences, including operation time, duration of hospital stay. However, the duration of the catheterization of Group 1 was shorter than that of Group 2 (1.38 ± 0.55 vs. 1.90 ± 1.81 days, p < 0.001). Conclusions: Even for cases of residual BPH, salvage HoLEP is a feasible and effective procedure for treating residual adenoma along the anatomical plane. PMID:24839489

  8. LD-pumped erbium and neodymium lasers with high energy and output beam quality

    NASA Astrophysics Data System (ADS)

    Kabanov, Vladimir V.; Bezyazychnaya, Tatiana V.; Bogdanovich, Maxim V.; Grigor'ev, Alexandr V.; Lebiadok, Yahor V.; Lepchenkov, Kirill V.; Ryabtsev, Andrew G.; Ryabtsev, Gennadii I.; Shchemelev, Maxim A.

    2013-05-01

    Physical and fabrication peculiarities which provide the high output energy and beam quality for the diode pumped erbium glass and Nd:YAG lasers are considered. Developed design approach allow to make passively Q-switched erbium glass eye-safe portable laser sources with output energy 8 - 12 mJ (output pulse duration is less than 25 ns, pulse repetition rate up to 5 Hz) and beam quality M2 less than 1.3. To reach these values the erbium laser pump unit parameters were optimized also. Namely, for the powerful laser diode arrays the optimal near-field fill-factor, output mirror reflectivity and heterostructure properties were determined. Construction of advanced diode and solid-state lasers as well as the optical properties of the active element and the pump unit make possible the lasing within a rather wide temperature interval (e.g. from minus forty till plus sixty Celsius degree) without application of water-based chillers. The transversally pumped Nd:YAG laser output beam uniformity was investigated depending on the active element (AE) pump conditions. In particular, to enhance the pump uniformity within AE volume, a special layer which practically doesn't absorb the pump radiation but effectively scatters the pump and lasing beams, was used. Application of such layer results in amplified spontaneous emission suppression and improvement of the laser output beam uniformity. The carried out investigations allow us to fabricate the solid-state Nd:YAG lasers (1064 nm) with the output energy up to 420 mJ at the pulse repetition rate up to 30 Hz and the output energy up to 100 mJ at the pulse repetition rate of of 100 Hz. Also the laser sources with following characteristics: 35 mJ, 30 Hz (266 nm); 60 mJ, 30 Hz (355 nm); 100 mJ, 30 Hz (532 nm) were manufactured on the base of the developed Nd:YAG quantrons.

  9. Implementation of Lean System on Erbium Doped Fibre Amplifier Manufacturing Process to Reduce Production Time

    NASA Astrophysics Data System (ADS)

    Maneechote, T.; Luangpaiboon, P.

    2010-10-01

    A manufacturing process of erbium doped fibre amplifiers is complicated. It needs to meet the customers' requirements under a present economic status that products need to be shipped to customers as soon as possible after purchasing orders. This research aims to study and improve processes and production lines of erbium doped fibre amplifiers using lean manufacturing systems via an application of computer simulation. Three scenarios of lean tooled box systems are selected via the expert system. Firstly, the production schedule based on shipment date is combined with a first in first out control system. The second scenario focuses on a designed flow process plant layout. Finally, the previous flow process plant layout combines with production schedule based on shipment date including the first in first out control systems. The computer simulation with the limited data via an expected value is used to observe the performance of all scenarios. The most preferable resulted lean tooled box systems from a computer simulation are selected to implement in the real process of a production of erbium doped fibre amplifiers. A comparison is carried out to determine the actual performance measures via an analysis of variance of the response or the production time per unit achieved in each scenario. The goodness of an adequacy of the linear statistical model via experimental errors or residuals is also performed to check the normality, constant variance and independence of the residuals. The results show that a hybrid scenario of lean manufacturing system with the first in first out control and flow process plant lay out statistically leads to better performance in terms of the mean and variance of production times.

  10. Performance characterization of new erbium-doped fibers using MCVD nanoparticle doping process

    NASA Astrophysics Data System (ADS)

    Boivin, David; Pastouret, Alain; Burov, Ekaterina; Gonnet, Cédric; Cavani, Olivier; Lempereur, Simon; Sillard, Pierre

    2011-02-01

    In 2009, we introduced a new doping concept involving Al2O3/rare-earth nanoparticles (NP) in a MCVD-compatible process finding potential applications in Erbium-, Ytterbium- or Erbium-Ytterbium-doped fiber amplifiers and lasers.1 This approach, motivated by the need for increased efficiencies and improved attributes, is characterized by the ability to control the rare-earth ion environment independently from the core composition. The NP matrix can therefore be viewed as an optimized sub-micronic amplifying medium for the embedded rareearth ion. The first experimental evidence to support this idea is reported in a comparative study with a standard process2 where homogeneous up-conversion (HUC) and pair-induced quenching (PIQ) levels are extracted from Er3+ unsaturable absorption measurements. NP-based fibers are found to mitigate the effects of the Er3+ concentration increase seen in standard heavily-doped fibers. This conclusion is particularly clear when focusing on the HUC coefficient evolution since, for a given type of NP, its level is independent from the Er3+ concentration in the doped zone. In this paper, we address our most recent work completing these preliminary results. First, we investigate the quenching signature of a new NP design and its behavior when incorporated in different core matrices. The interplay is further analysed by relating this set of measurements to practical EDFA performances. Gain and noise characteristics of typical WDM amplifiers operating points serve as key benchmarking indicators to identify the benefits of NP Erbium-doped fibers in the wide variety of EDFAs implementations.

  11. Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.

    PubMed

    Saracoglu, Sibel; Soylak, Mustafa; Cabuk, Dilek; Topalak, Zeynep; Karagozlu, Yasemin

    2012-01-01

    The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry. PMID:22816279

  12. Use of the holmium:YAG laser for percutaneous photothermal ablation of cervical invertebral disks in dogs

    NASA Astrophysics Data System (ADS)

    Rochat, Mark; Henry, George A.; Campbell, Gregory A.; Stair, Ernest L.; Bartels, Kenneth E.; Dickey, Tom

    1999-06-01

    Holmium:YAG laser ablation of thoracolumbar disks in dogs has been shown to be an effective alternative to standard surgical fenestration techniques. Our hypothesis was the Holmium:YAG laser could be equally effective and safe when used to ablate cervical intervertebral disks. Six normal chondrodystrophoid breed dogs were used. A sterile, cleaved, 320 micrometers , low-OH quartz optical fiber was inserted into each needle and the laser activated for 40 s at 2 W mean power and a 15 Hz pulse repetition rate for a total of 80 J. Dogs were observed in pain, neurological deficits, or other complications for 24 weeks. At 24 weeks, dogs were euthanatized and cervical disks collected and placed in 10 percent neutral buffered formalin. Disks were decalcified, sectioned at 5 micrometers , and stained with H and E. No problems were encountered during the procedure except occasional difficulties passing the needle by the shoulder to enter the C6-7 disk space. No complications, including neurologic deficits or pain were observe during the 24 weeks. Histologic examination revealed varying degrees of necrosis and defects created in the nucleus pulposus by laser irradiation. In some instances there was evidence of mild adjacent annular and bony thermal injury. On the basis of these result, the Ho:YAG laser appears to be a safe and efficacious method for ablation of canine cervical disks.

  13. Gamma spectrometry and chemical characterization of ceramic seeds with samarium-153 and holmium-166 for brachytherapy proposal.

    PubMed

    Valente, Eduardo S; Campos, Tarcísio P R

    2010-12-01

    Ceramic seeds were synthesized by the sol-gel technique with Si:Sm:Ca and Si:Ho:Ca. One set of seeds was irradiated in the TRIGA type nuclear reactor IPR-R1 and submitted to instrumental neutron activation analysis (INAA), K(0) method, to determine mass percentage concentration of natural samarium and holmium in the seed as well as to determine all existing radionuclides and their activities. Attention was paid to discrimination of Si-31, Ca-40, Ca-45, Ca-47, Ca-49, Sm-145, Sm-155, Sm-153 and Ho-166. A second sample was submitted to atomic emission spectrometry (ICP-AES) also to determine samarium and holmium concentrations in weight. A third sample was submitted to X-ray fluorescence spectrometry to qualitatively determine chemical composition. The measured activity was due to Sm-153 and Ho-166 with a well-characterized gamma spectrum. The X-ray fluorescence spectrum demonstrated that there is no discrepancy in seed composition. The maximum ranges in the water of beta particles from Sm-153 and Ho-166 decay were evaluated, as well as the dose rate and total dose delivered within the volume delimited by the range of the beta particles. The results are relevant for investigation of the viability of producing Sm-153 and Ho-166 radioactive seeds for use in brachytherapy. PMID:20685128

  14. Performance analysis of bi-directional broadband passive optical network using erbium-doped fiber amplifier

    NASA Astrophysics Data System (ADS)

    Almalaq, Yasser; Matin, Mohammad A.

    2014-09-01

    The broadband passive optical network (BPON) has the ability to support high-speed data, voice, and video services to home and small businesses customers. In this work, the performance of bi-directional BPON is analyzed for both down and up streams traffic cases by the help of erbium doped fiber amplifier (EDFA). The importance of BPON is reduced cost. Because PBON uses a splitter the cost of the maintenance between the providers and the customers side is suitable. In the proposed research, BPON has been tested by the use of bit error rate (BER) analyzer. BER analyzer realizes maximum Q factor, minimum bit error rate, and eye height.

  15. Effects of erbium doping of indium tin oxide electrode in resistive random access memory

    NASA Astrophysics Data System (ADS)

    Chen, Po-Hsun; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Pan, Chih-Hung; Lin, Chih-Yang; Jin, Fu-Yuan; Chen, Min-Chen; Huang, Hui-Chun; Lo, Ikai; Zheng, Jin-Cheng; Sze, Simon M.

    2016-03-01

    Identical insulators and bottom electrodes were fabricated and capped by an indium tin oxide (ITO) film, either undoped or doped with erbium (Er), as a top electrode. This distinctive top electrode dramatically altered the resistive random access memory (RRAM) characteristics, for example, lowering the operation current and enlarging the memory window. In addition, the RESET voltage increased, whereas the SET voltage remained almost the same. A conduction model of Er-doped ITO is proposed through current-voltage (I-V) measurement and current fitting to explain the resistance switching mechanism of Er-doped ITO RRAM and is confirmed by material analysis and reliability tests.

  16. Preparative scale separation of thulium from erbium for neutron capture cross section measurements - Part: Preparative scale

    DOE PAGESBeta

    Birnbaum, Eva R.; Bene, Balazs J.; Taylor, Wayne Allen; Sudowe, Ralf

    2016-06-04

    Here, this paper discusses the development of a separation method for isolation of 171Tm from a half-gram irradiated erbium target in support of stockpile stewardship and astrophysics research. The developed procedure is based on cation exchange separation using alpha-hydroxyisobutyric acid (α-HIBA) as chelating agent. It is able to achieve either a decontamination factor of 1.4(4) × 105 with 68.9(3) % recovery or 95.4(3) % recovery with a decontamination factor of 5.82(7) × 103 for a mock 500-mg target containing 17.9 mg thulium in a single pass-through at room temperature.

  17. Visible continuum generation using a femtosecond erbium-doped fiber laser and a silica nonlinear fiber.

    PubMed

    Nicholson, J W; Bise, R; Alonzo, J; Stockert, T; Trevor, D J; Dimarcello, F; Monberg, E; Fini, J M; Westbrook, P S; Feder, K; Grüner-Nielsen, L

    2008-01-01

    Supercontinuum extending to visible wavelengths is generated in a hybrid silica nonlinear fiber pumped at 1560 nm by a femtosecond, erbium-doped fiber laser. The hybrid nonlinear fiber consists of a short length of highly nonlinear, germano-silicate fiber (HNLF) spliced to a length of photonic crystal fiber (PCF). A 2 cm length of HNLF provides an initial stage of continuum generation due to higher-order soliton compression and dispersive wave generation before launching into the PCF. The visible radiation is generated in the fundamental mode of the PCF. PMID:18157247

  18. Poor fluorinated graphene sheets carboxymethylcellulose polymer composite mode locker for erbium doped fiber laser

    SciTech Connect

    Mou, Chengbo E-mail: a.rozhin@aston.ac.uk; Turitsyn, Sergei; Rozhin, Aleksey E-mail: a.rozhin@aston.ac.uk; Arif, Raz; Lobach, Anatoly S.; Spitsina, Nataliya G.; Khudyakov, Dmitry V.; Kazakov, Valery A.

    2015-02-09

    We report poor fluorinated graphene sheets produced by thermal exfoliation embedding in carboxymethylcellulose polymer composite (GCMC) as an efficient mode locker for erbium doped fiber laser. Two GCMC mode lockers with different concentration have been fabricated. The GCMC based mode locked fiber laser shows stable soliton output pulse shaping with repetition rate of 28.5 MHz and output power of 5.5 mW was achieved with the high concentration GCMC, while a slightly higher output power of 6.9 mW was obtained using the low concentration GCMC mode locker.

  19. Smart Q-switching for single-pulse generation in an erbium-doped fiber laser.

    PubMed

    Escalante-Zarate, Luis; Barmenkov, Yuri O; Kolpakov, Stanislav A; Cruz, José L; Andrés, Miguel V

    2012-02-13

    In this paper, we report an active Q-switching of an erbium-doped fiber laser with special modulation functions and novel laser geometry. We experimentally demonstrate that using such a smart Q-switch approach, Q-switch ripple-free pulses with Gaussian-like shape and 17.3 ns width can be easily obtained. The idea behind the smart Q-switch is to suppress one of two laser waves contra-propagating along the fiber cavity, which arises after Q-cell opening, and to eliminate the minor sub-pulses. PMID:22418199

  20. Fibercore AstroGain fiber: multichannel erbium doped fibers for optical space communications

    NASA Astrophysics Data System (ADS)

    Hill, Mark; Gray, Rebecca; Hankey, Judith; Gillooly, Andy

    2014-03-01

    Fibercore have developed AstroGainTM fiber optimized for multichannel amplifiers used in optical satellite communications and control. The fiber has been designed to take full advantage of the photo-annealing effect that results from pumping in the 980nm region. The proprietary trivalent structure of the core matrix allows optimum recovery following radiation damage to the fiber, whilst also providing a market leading Erbium Doped Fiber Amplifier (EDFA) efficiency. Direct measurements have been taken of amplifier efficiency in a multichannel assembly, which show an effective photo-annealing recovery of up to 100% of the radiation induced attenuation through excitation of point defects.

  1. Resonant pumped erbium-doped waveguide lasers using distributed Bragg reflector cavities.

    PubMed

    Singh, G; Purnawirman, P; Bradley, J D B; Li, N; Magden, E S; Moresco, M; Adam, T N; Leake, G; Coolbaugh, D; Watts, M R

    2016-03-15

    This Letter reports on an optical pumping scheme, termed resonant pumping, for an erbium-doped distributed feedback (DFB) waveguide laser. The scheme uses two mirrors on either side of the DFB laser, forming a pump cavity that recirculates the unabsorbed pump light. Symmetric distributed Bragg reflectors are used as the mirrors and are designed by matching the external and internal quality factors of the cavity. Experimental demonstration shows lasing at an optical communication wavelength of around 1560 nm and an improvement of 1.8 times in the lasing efficiency, when the DFB laser is pumped on-resonance. PMID:26977666

  2. Highly stable and efficient erbium-doped 2.8 microm all fiber laser.

    PubMed

    Bernier, Martin; Faucher, Dominic; Caron, Nicolas; Vallée, Réal

    2009-09-14

    We demonstrate the efficient and stable CW laser operation at 2.824 microm of a diode-pumped erbium-doped fluoride fiber laser employing an intracore fiber Bragg grating high reflector. An output power of 5 W and an optical-to-optical conversion efficiency of 32% are reported. The temporal and spectral stability of the laser represent a significant improvement over previous work. This report paves the way to the commercialization of compact and stable fiber lasers for spectroscopic and medical applications. PMID:19770912

  3. Highly efficient and high output power of erbium doped fiber laser in a linear cavity configuration

    NASA Astrophysics Data System (ADS)

    Awang, N. A.; Zulkifli, M. Z.; Norizan, S. F.; Harun, S. W.; Ghani, Z. A.; Ahmad, H.

    2010-10-01

    A simple Erbium Doped Fiber Laser (EDFL) in linear cavity configuration is reported. The cavity design is based on an FBG as a back reflector, and a loop back optical circulator with an output coupler as the front reflector. Different coupling ratios of the coupler are tested and 50: 50 provides the highest coupling output power of 22.06 dBm (160.7 mW). The pump power conversion efficiency is about 95% when pumping with two pump lasers at 1460 and 1490 nm with combined pumping power of 545 mW. The laser output has a measured linewidth of 0.0179 nm.

  4. 10-GHz, 1.3-ps erbium fiber laser employing soliton pulse shortening

    NASA Astrophysics Data System (ADS)

    Carruthers, Thomas F.; Duling, Irl N., III

    1996-12-01

    An actively mode-locked single-polarization erbium fiber laser modulated at 10 GHz utilizes intracavity soliton formation to produce 1.3-ps pulses, well below the Kuizenga-Siegman limit, without passive mode locking. The observed degree of pulse shortening agrees with the predictions of recently developed soliton laser models. The pulse dropout ratio was measured to be less than 10-12 , and the rms amplitude and phase jitter are less than 1.1% and 0.16 ps, respectively.

  5. Near infrared emission for erbium-doped calcium aluminum silicate glass

    NASA Astrophysics Data System (ADS)

    Lihui, Huang; Xingren, Liu; Baojiu, Chen; Jiuling, Lin

    2001-09-01

    In this work, erbium-doped calcium aluminum silicate (CAS) glass has been synthesized by solid-state reaction. Intense emission at 1534 nm, corresponding to the 4I13/2→ 4I15/2 transition of the Er 3+ ion, was observed upon both 488 nm Ar + laser and 978 nm diode laser excitations at room temperature. The luminescence mechanisms in the glass are discussed. These results indicate this glass is a promising laser material with its high chemical durability and thermal stability.

  6. Microprocessing of human hard tooth tissues surface by mid-infrared erbium lasers radiation

    NASA Astrophysics Data System (ADS)

    Belikov, Andrey V.; Shatilova, Ksenia V.; Skrypnik, Alexei V.

    2015-03-01

    A new method of hard tooth tissues laser treatment is described. The method consists in formation of regular microdefects on tissue surface by mid-infrared erbium laser radiation with propagation ratio M2<2 (Er-laser microprocessing). Proposed method was used for preparation of hard tooth tissues surface before filling for improvement of bond strength between tissues surface and restorative materials, microleakage reduction between tissues surface and restorative materials, and for caries prevention as a result of increasing microhardness and acid resistance of tooth enamel.

  7. Infrared spectroscopy and upconversion luminescence behaviour of erbium doped yttrium (III) oxide phosphor

    NASA Astrophysics Data System (ADS)

    Dubey, Vikas; Tiwari, Ratnesh; Tamrakar, Raunak Kumar; Rathore, Gajendra Singh; Sharma, Chitrakant; Tiwari, Neha

    2014-11-01

    The paper reports upconversion luminescence behaviour and infra-red spectroscopic pattern of erbium doped yttrium (III) oxide phosphor. Sample was synthesized by solid state reaction method with variable concentration or erbium (0.5-2.5 mol%). The conventional solid state method is suitable for large scale production and eco-friendly method. The prepared sample was characterized by X-ray diffraction (XRD) technique. From structural analysis by XRD technique shows cubic structure of prepared sample with variable concentration of erbium and no impurity phase were found when increase the concentration of Er3+. Particle size was calculated by Scherer's formula and it varies from 67 nm to 120 nm. The surface morphology of prepared phosphor was determined by field emission gun scanning electron microscopy (FEGSEM) technique. The surface morphology of the sample shows good connectivity with grains as well as some agglomerates formation occurs in sample. The functional group analysis was done by Fourier transform infra-red technique (FTIR) analysis which confirm the formation of Y2O3:Er3+ phosphor was prepared. The results indicated that the Y2O3:Er3+ phosphors might have high upconversion efficiency because of their low vibrational energy. Under 980 nm laser excitation sample shows intense green emission at 555 nm and orange emission at 590 nm wavelength. For green emission transition occurs 2H11/2 → 4I15/2, 4S3/2 → 4I15/2 for upconversion emissions. Excited state absorption and energy transfer process were discussed as possible upconversion mechanisms. The near infrared luminescence spectra was recorded. The upconversion luminescence intensity increase with increasing the concentration or erbium up to 2 mol% after that luminescence intensity decreases due to concentration quenching occurs. Spectrophotometric determinations of peaks are evaluated by Commission Internationale de I'Eclairage (CIE) technique. From CIE technique the dominant peak of from PL spectra shows

  8. Erbium Doping Effects on the Conduction Band Edge in Germanium Nanocrystals

    SciTech Connect

    Meulenberg, Robert W.; Willey, Trevor M.; Lee, Jonathan R.; Terminello, Louis J.; Van Buren, T.

    2011-05-16

    We have produced erbium-doped germanium nanocrystals (NCs) using a new two cell physical vapor deposition system. Using element specific x-ray techniques (absorption and photoemission), we are able to probe the chemical environment of Er in the Ge NCs. Evidence for the optically active Er3+ state is seen at low Er concentrations, with a disruption of NC formation at high Er concentrations. The x-ray absorption measurements suggest that the Er occupies lattice sites near the surface of the NC. Analysis of the quantum confinement effect with Er doping suggests that the native quantum properties of the Ge NC are maintained at low Er concentrations.

  9. Generation of stable cnoidal waves in an erbium doped fiber laser system

    NASA Astrophysics Data System (ADS)

    Wilson, Mario; González-García, Andrés; Aboites, Vicente

    2016-05-01

    In this work an all-fiber laser system able to produce stable cnoidal waves in both limits, i.e. in sinusoidal and soliton limits, is presented. The system is constructed using an erbium highly-doped fiber as an active media and an electrooptic modulator as the core of the control tool. This control tool is able to modulate the cavity losses. The direct modulation allows to control the pulses properties, shape, width and intensity. The proposed system is well described by a three level laser model based on the Statz-de Mars rate equations. Numerical and Experimental results are presented.

  10. 120 nm Bandwidth noise-like pulse generation in an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Zhao, L. M.; Tang, D. Y.; Cheng, T. H.; Tam, H. Y.; Lu, C.

    2008-01-01

    We report on the generation of noise-like pulses with up to 120 nm bandwidth in a passively mode-locked erbium-doped fiber ring laser. By inserting a segment of slightly normal dispersion fiber in a mode-locked fiber laser cavity, we found that the spectrum of the noise-like pulse emission of the laser can be significantly broadened as a result of the four-wave-mixing and the soliton self-frequency shift effects in the inserted fiber.

  11. Structural investigation of praseodymium potassium hexacyanoferrate (II) tetrahydrate, PrKFe(CN)/sub 6/ x 4H/sub 2/O

    SciTech Connect

    Mullica, D.F.; Sappenfield, E.L. Perkins, H.O.

    1988-03-01

    Single-crystal and powder X-ray diffraction data, thermal gravimetric analysis, and infrared spectral data are present for PrKFe(CN)/sub 6/ x 4H/sub 2/O. The crystal structure has been determined by single-crystal diffractometry and refined by the least-squares method to yield R = 0.0149 and R/sub w/ = 0.0155. The praseodymium ions are linked nonlinearly to the FeC/sub 6/ octahedra by cyanide bridges. Cavities within the structure are occupied by potassium ions and zeolitic water molecules which are within hydrogen bonding distance to the water molecules which are bonded to the nine-coordinated praseodymium ions, PrN/sub 6/(H/sub 2/O)/sub 3/. The powder diffraction data obtained by employing a Siemens Debye-Scherrer camera have yielded cell parameters of a = 7.374(2) and c = 13.816(3) A. The compound is hexagonal, P6/sub 3//m (No. 176), D/sub M/ = 2.34(3) Mg m/sup -3/, and D/sub x/ = 2.368 Mg m/sup -3/. The powder diffraction data have been evaluated and the resultant quantitative figures of merit are F/sub 30/ = 30(0.021, 48) and M20 = 29.7. Important bond lengths are: Pr-N = 2.540(3); Fe-C = 1.908(3); Pr-O = 2.704(4); and C=N = 1.159(4) A.

  12. Effect of praseodymium doping on the structural, magnetic and magnetocaloric properties of Sm0.55Sr0.45MnO3 manganite

    NASA Astrophysics Data System (ADS)

    Mleiki, A.; Othmani, S.; Cheikhrouhou-Koubaa, W.; Koubaa, M.; Cheikhrouhou, A.; Hlil, E. K.

    2015-12-01

    The effect of praseodymium doping on the microstructure, magnetic and magnetocaloric effects in Sm0.55-xPrxSr0.45MnO3 (x=0.0 and x=0.1) has been investigated. Our compounds have been elaborated using the conventional solid-state reaction at high temperature. X-Ray diffraction study reveals that our samples crystallize in the distorted orthorhombic system with Pbnm space group. Magnetization measurements M (T) at H=0.05 T were performed and show a paramagnetic (PM) to ferromagnetic (FM) transition with decreasing temperature. Praseodymium doping leads to an increase of the Curie temperature TC from 95 K (x=0.0) to 132 K (x=0.1). Moreover, we observe a small anomaly in the M (T) behavior around 30 K. It has been shown that x=0.1 sample exhibit first order FM-PM phase transition under low magnetic field accompanied by a thermal hysteresis in the field cooled cooling and warming protocols. However, the phase transition from PM to FM is modified from first order to second order above a critical field HC. A metamagnetic behavior has been observed in the M (H) curves around 110 K for x=0.0 and 160 K for x=0.1. The maximum of the magnetic entropy change (- ΔSMmax) was calculated using the isothermal magnetization curves M (H) under magnetic field change of 5 T and is found to be 6.56 J kg-1 K-1 for x=0.0 and 7.14 J kg-1 K-1 for x=0.1. The relative cooling power (RCP) is found to be 222.6 J/Kg and 258.8 J/Kg for x=0.0 and x=0.1, respectively. This suggests that these compounds may be suitable candidates for magnetic refrigeration.

  13. Ultra-stable harmonically mode-locked erbium-doped waveguide laser

    NASA Astrophysics Data System (ADS)

    Fanto, M. L.; Erdmann, R. K.; Wysocki, B. T.; Malowicki, J. E.; McEwen, T. A.

    2007-04-01

    Generation of stable pulses and a frequency stabilized optical comb are two key requirements for Fourier Based Arbitrary Waveform Generation (AWG) techniques. The longitudinal mode spacing of the laser must remain as stable as possible to permit effective isolation and processing of the modes for waveform synthesis. The short and long term temporal stability ultimately limits the system's precision as well as its operability in fielded systems. A packaged erbium-doped waveguide provided a highly compact gain medium for the harmonically mode-locked laser design. Stability was achieved by use of an intracavity etalon for frequency stabilization of the optical comb, a Pound-Drever- Hall (PDH) method, and an active bias feedback loop for low frequency noise suppression. The temperature was controlled to limit cavity length variation, and the contribution to stability of each method is quantitatively assessed. The system's stable operating time was increased from hours to greater than a day, and the timing jitter is demonstrated to be lower than that of commercially available erbium-doped fiber laser (EDFL) systems. Applications to optical signal synthesis and Laser Radar are briefly discussed.

  14. High-coherence light extraction through a compact Brillouin/erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, Mo; Wang, Jianfei; Chen, Wei; Sun, Shilin; Meng, Zhou

    2016-05-01

    High-coherence light is stringently demanded in high-accuracy interferometric optical fiber sensors, where the phase noise of the light source greatly affects the sensitivity of the whole system. Distributed-feedback laser diodes with a phase noise of -80 ~ -90 dB/Hz1/2 at 1 kHz (with 1 m optical path difference) is now easily obtained, but the interferometric fiber sensors requires the laser source with the phase noise lower than -100 dB/Hz1/2. Lasers with ultra-low-noise usually require complicated and sophisticated techniques. We propose a novel structure to realize high-coherence light extraction through a compact Brillouin/erbium fiber laser (BEFL) which uses a length of 4 m erbium-doped fiber as both the Brillouin and linear gain media. The phase noise of the Brillouin pump light is greatly smoothed and suppressed after being transferred to the Brillouin Stokes light. High-coherence light with the phase noise of about -104 dB/Hz1/2 at 1 kHz is extracted through the compact BEFL from a commercialized laser diode with the phase noise of about -89 dB/Hz1/2. The capability of phase noise suppression in the compact BEFL presents much importance especially in large-array interferometric fiber sensor systems.

  15. Acoustical measurements during Erbium:YAG laser ablation of porcine calcified tissues

    NASA Astrophysics Data System (ADS)

    Saaf, Randall R.; Wong, Brian J.; Milner, Thomas E.; Peavy, George M.; Anvari, Bahman

    1998-07-01

    The Erbium:YAG laser ((lambda) equals 2.94 micrometer) has been suggested for use in dental, orthopedic, and middle ear surgery due to decreased thermal trauma, precise ablation characteristics, and potential fiber optic delivery. While there has been much focus on the thermal and photoacoustic events that occur during pulsed laser ablation of hard tissue, there are few studies that examine the acoustic energy generated by these devices during ablation from an audiologic standpoint. In this study, the porcine otic capsule, nasal bone, and teeth were irradiated with an Erbium:YAG laser. Frequencies of 5 and 10 Hz shot repetition rate were used with .5 to 4 W average power. Additionally, a burst mode consisting of three pulses was used with .2 to 1.4 J total energy. During ablation, acoustic measurements were made using a sound level meter held 20 mm away from the target site. A constant spot size of 500 micrometer was maintained for each laser blast. With each set of laser parameters, the sound intensity (dB SPL) exceeded 70 dB. Peak intensity measurements of 95 dB were measured. The clinical significance of these findings is discussed and the acoustical aspects of middle ear function and noise trauma are reviewed.

  16. Observations of proton beam enhancement due to erbium hydride on gold foil targets

    SciTech Connect

    Offermann, D. T.; Van Woerkom, L. D.; Freeman, R. R.; Foord, M. E.; Hey, D.; Key, M. H.; Mackinnon, A. J.; MacPhee, A. G.; Patel, P. K.; Ping, Y.; Sanchez, J. J.; Shen, N.; Bartal, T.; Beg, F. N.; Espada, L.; Chen, C. D.

    2009-09-15

    Recent theoretical work suggests that the conversion efficiency from laser to protons in laser irradiated thin foil experiments increases if the atomic mass of nonhydrogen atoms on the foil rear surface increases. Experiments were performed at the Lawrence Livermore National Laboratory Jupiter Laser Facility to observe the effect of thin foils coated with erbium hydride on the conversion efficiency from laser to protons. Gold foils with and without the rear surface coated with ErH{sub 3} were irradiated using the ultrashort pulse, 40 TW Callisto laser. An argon-ion etching system was used to remove naturally occurring nanometer thick surface layer contaminants from the hydride. With the etcher, gold with ErH{sub 3} showed a 25% increase in the conversion efficiency to protons above 3.4 MeV relative to contaminants, where C{sup +4} and H{sup +} were the dominant ion species. No difference in the ion signal was observed without first cleaning the hydrides. Simulations using the hybrid PIC code, LSP, revealed that the increase due to erbium hydride versus contaminants is 37% for protons above 3 MeV.

  17. Surface-Directed Synthesis of Erbium-Doped Yttrium Oxide Nanoparticles within Organosilane Zeptoliter Containers

    PubMed Central

    2015-01-01

    We introduce an approach to synthesize rare earth oxide nanoparticles using high temperature without aggregation of the nanoparticles. The dispersity of the nanoparticles is controlled at the nanoscale by using small organosilane molds as reaction containers. Zeptoliter reaction vessels prepared from organosilane self-assembled monolayers (SAMs) were used for the surface-directed synthesis of rare earth oxide (REO) nanoparticles. Nanopores of octadecyltrichlorosilane were prepared on Si(111) using particle lithography with immersion steps. The nanopores were filled with a precursor solution of erbium and yttrium salts to confine the crystallization step to occur within individual zeptoliter-sized organosilane reaction vessels. Areas between the nanopores were separated by a matrix film of octadecyltrichlorosilane. With heating, the organosilane template was removed by calcination to generate a surface array of erbium-doped yttria nanoparticles. Nanoparticles synthesized by the surface-directed approach retain the periodic arrangement of the nanopores formed from mesoparticle masks. While bulk rare earth oxides can be readily prepared by solid state methods at high temperature (>900 °C), approaches for preparing REO nanoparticles are limited. Conventional wet chemistry methods are limited to low temperatures according to the boiling points of the solvents used for synthesis. To achieve crystallinity of REO nanoparticles requires steps for high-temperature processing of samples, which can cause self-aggregation and dispersity in sample diameters. The facile steps for particle lithography address the problems of aggregation and the requirement for high-temperature synthesis. PMID:25163977

  18. Efficient S-Band Amplification Using Depressed-Cladding Erbium-Doped Silica Fibers

    NASA Astrophysics Data System (ADS)

    Rosolem, J. B.; Romero, M. A.

    2008-10-01

    In this paper we review our work to achieve S-band amplification using only erbium doped silica fibers. To this end, double-pass and single pass erbium doped depressed cladding fiber amplifier designed for S band operation are evaluated under changes of the input optical power, pumping power and fiber bending radius. The double pass configuration employs the usual combination of a circulator and a Faraday rotator mirror while the single pass is based on the co-propagating scheme. The amplifiers were characterized in terms of gain and noise figure. It is demonstrated that the double pass topology shows much improved gain performance compared to the single pass configuration although the noise figure is slightly degraded by counter-propagating ASE. Next, the amplifier double pass topology is properly modified to achieve signal amplification simultaneously over S, C and L bands. An embedded dispersion compensating fiber is included and the experimental characterization is carried out in terms gain and noise figure over the CWDM wavelength grid. By providing optical gain to seven CWDM channels spectrally located between 1490 and 1610 nm, the amplifier can extend the reach of a 16-channel CWDM optical bus well beyond the 100 km limit. The system results are then compared to those obtained by using a SOA (semiconductor optical amplifier), under the same experimental conditions.

  19. Gamma-ray-induced damage and recovery behavior in an erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Bussjager, Rebecca J.; Hayduk, Michael J.; Johns, Steven T.; Taylor, Linda R.; Taylor, Edward W.

    2002-01-01

    Erbium-doped fiber lasers (EDFLs) may soon find applications in space as high bit rate optical communication systems and photonic analog-to-digital converters (ADCs). The rapid advancement in digital signal processing systems has led to an increased interest in the direct digitization of high- frequency analog signals. The potential high bandwidth, reduced weight, and reduced power requirements makes photonics an attractive technology for wide-band signal conversion as well as for use in space-based platforms. It is anticipated that photonic ADCs will be able to operate at sampling rates and resolutions far greater than current electronic ADCs. The high repetition rates and narrow pulse widths produced by EDFLs allow for high-speed impulse sampling of analog signals thus making it a vital component of a photonic ADC. In this paper we report on the in situ gamma-ray irradiation of an actively mode-locked EDFL operating at 1530 nm. The onset, growth and extent of ionization induced damage under time-resolved operational conditions is presented. The laser consisted of approximately 3 meters of erbium-doped fiber pumped by a laser diode operating at 980 nm. The picosecond pulses produced by the laser were initiated and controlled by a Mach-Zehnder lithium niobate electro-optic modulator. The active mode-locking element allowed for the precise timing control of the laser repetition rate which is critical in high-speed optical networking systems as well as in photonic ADCs.

  20. Surface-directed synthesis of erbium-doped yttrium oxide nanoparticles within organosilane zeptoliter containers.

    PubMed

    Englade-Franklin, Lauren E; Morrison, Gregory; Verberne-Sutton, Susan D; Francis, Asenath L; Chan, Julia Y; Garno, Jayne C

    2014-09-24

    We introduce an approach to synthesize rare earth oxide nanoparticles using high temperature without aggregation of the nanoparticles. The dispersity of the nanoparticles is controlled at the nanoscale by using small organosilane molds as reaction containers. Zeptoliter reaction vessels prepared from organosilane self-assembled monolayers (SAMs) were used for the surface-directed synthesis of rare earth oxide (REO) nanoparticles. Nanopores of octadecyltrichlorosilane were prepared on Si(111) using particle lithography with immersion steps. The nanopores were filled with a precursor solution of erbium and yttrium salts to confine the crystallization step to occur within individual zeptoliter-sized organosilane reaction vessels. Areas between the nanopores were separated by a matrix film of octadecyltrichlorosilane. With heating, the organosilane template was removed by calcination to generate a surface array of erbium-doped yttria nanoparticles. Nanoparticles synthesized by the surface-directed approach retain the periodic arrangement of the nanopores formed from mesoparticle masks. While bulk rare earth oxides can be readily prepared by solid state methods at high temperature (>900 °C), approaches for preparing REO nanoparticles are limited. Conventional wet chemistry methods are limited to low temperatures according to the boiling points of the solvents used for synthesis. To achieve crystallinity of REO nanoparticles requires steps for high-temperature processing of samples, which can cause self-aggregation and dispersity in sample diameters. The facile steps for particle lithography address the problems of aggregation and the requirement for high-temperature synthesis. PMID:25163977

  1. Deuterium permeation through erbium oxide coatings on RAFM steels by a dip-coating technique

    NASA Astrophysics Data System (ADS)

    Chikada, Takumi; Naitoh, Shunya; Suzuki, Akihiro; Terai, Takayuki; Tanaka, Teruya; Muroga, Takeo

    2013-11-01

    A tritium permeation barrier is a promising solution for the problems of tritium loss and radiological safety in fusion blanket systems. In recent years, erbium oxide coatings have shown remarkable permeation reduction factors. One of the remaining issues for the coatings is the establishment of plant-scale fabrication. In this study, erbium oxide thin films have been fabricated by a dip-coating technique, which has the potential to coat a complex-shaped substrate, and deuterium permeation behavior in the coatings has been examined. Crack-free coatings were formed on a reduced activation ferritic/martensitic steel F82H substrate by use of a withdrawal speed of 1.0-1.4 mm s-1 and a heat-treatment process in hydrogen with moisture. In deuterium permeation experiments, a 0.2-μm-thick coating on both sides of the substrate showed a reduction factor of 600-700 in comparison with a F82H substrate below 873 K; however, the coating degraded at above 923 K because of crack formation. A double-coated sample indicated a reduction factor of up to 2000 and did not degrade at up to 923 K. The driving pressure dependence of the deuterium permeation flux indicated that the permeation tended to be limited by surface reactions at low temperatures. Optimization of the number of layers has the possibility to reduce degradation at high temperatures while maintaining high permeation reduction factors.

  2. Experimental and numerical study of high order Stokes lines in Brillouin-erbium fiber laser

    SciTech Connect

    Yuan, Yijun; Yao, Yong Xiao, Jun Jun; Yang, Yanfu; Tian, Jiajun; Liu, Chao

    2014-01-28

    We experimentally study the dependences of high-order Stokes lines on the erbium-doped fiber (EDF) pump power P{sub EDF}, the Brillouin pump (BP) power P{sub BP}, and its working wavelength in a multiwavelength Brillouin erbium-doped fiber laser (MBEFL). By using the rate and propagation equations, and the coupled wave equations of stimulated Brillouin scattering, we establish a lumped model to describe the MBEFL. Numerical simulations show that the number of Stokes lines can be increased by decreasing the spacing between the BP wavelength and the EDF peak gain or P{sub BP} as long as it is larger than a critical value P{sub BP}{sup (cr)}=1.7 mW, or by increasing P{sub EDF} without reaching a saturation value P{sub EDF}{sup (cr)}=250 mW. However, when P{sub BP} and P{sub EDF} are varied beyond P{sub BP}{sup (cr)} and P{sub EDF}{sup (cr)}, respectively, the number of Stokes lines is reduced, accompanied by some self-lasing cavity modes. These results by numerical simulation are consistent with experimental observations from the MBEFL.

  3. Spectroscopic studies of neutral erbium in a hollow cathode lamp: Electronic temperature and two-step optogalvanic spectroscopy

    NASA Astrophysics Data System (ADS)

    Bueno, Patricia; Victor, Alessandro R.; Santos, Jhonatha R. dos; Barreta, Luiz F. N.; Destro, Marcelo G.; Sbampato, Maria Esther; Neri, Jose W.; Silveira, Carlos A. B.

    2016-04-01

    This work reports the results obtained through spectroscopic studies developed on an erbium-neon hollow cathode lamp. First, emission spectra were obtained in order to estimate the electronic temperature of neutral erbium, which is an important plasma parameter for the calculation of atomic population in different energy levels. It was identified seven pairs of lines that can be used to estimate the electronic temperature of this metal by the two-line Boltzmann method. After these experiments, using the laser multistep excitation technique, three transitions for the first step excitation from the erbium ground state and eight transitions corresponding to the second step were observed. Four of these eight second steps correspond to erbium lines that were not reported in the literature before: 599.44 nm (17,157.31 → 33,844 cm- 1), 603.65 nm (17,073.80 → 33,635 cm- 1), 597.48 nm (17,029.06 → 33,761 cm- 1) and 597.56 nm (17,029.06 → 33,759 cm- 1).

  4. Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers

    NASA Astrophysics Data System (ADS)

    Chen, H.; Leblanc, M.; Schinn, G. W.

    2003-02-01

    We report on the experimental investigation of gain enhanced L-band erbium-doped fiber amplifiers (EDFA) by either recycling residual ASE or using a second C-band wavelength pump laser and on the experimental demonstration of L-band tunable erbium-doped fiber ring lasers. We observed that by reflecting ASE from pumped erbium-doped fiber (EDF) the L-band EDFA gain can be enhanced of 2-15 dB depending on amplifier designs. We also studied wavelength and power dependence of second pump laser on the gain enhanced L-band EDFA and found that an optimum wavelength for second pump laser was between 1550 and 1560 nm. Finally, a L-band tunable erbium-doped fiber laser was also constructed in which lazing oscillation was observed closed to 1624 nm by recycling residual ASE. This L-band tunable laser has a line-width of about 300 MHz, an output power of 1 mW, and a signal to source spontaneous emission ratio of 60 dB.

  5. Evaluation of the Removal Bacteria on Failed Titanium Implants After Irradiation With Erbium-Doped Yttrium Aluminium Garnet Laser.

    PubMed

    Scarano, Antonio; Nardi, Gianna; Murmura, Giovanna; Rapani, Manuela; Mortellaro, Carmen

    2016-07-01

    Peri-implantitis may occur because of biologic or mechanical factors. It can be treated by a variety of methods. The aim of the present study is to evaluate implant surface of failed oral titanium implants after being irradiated with erbium laser. PMID:27391491

  6. Histological changes and wound healing response following noncontact holmium: YAG laser thermal keratoplasty.

    PubMed Central

    Koch, D D

    1996-01-01

    PURPOSE: To evaluate acute histological changes and the induced wound healing response in corneal tissue following noncontact holmium:YAG laser thermal keratoplasty (LTK). METHODS: LTK using 10 pulses and a range of radiant energies was performed on 3 human corneas one day prior ro their removal at penetrating keratoplasty. Rabbit corneas were treated with 10-pulse and 5-pulse LTK and followed for up to 3 months. Tissues were studies with light and transmission electron microscopy and immunohistochemistry. RESULTS: The amount of acute tissue injury increased with increasing pulse radiant energy. In human corneas, changes in the irradiated zones included epithelial cell injury and death loss of fine filamentous structure in Bowman's layer, disruption of stromal lamallae, and keratocyte injury and death. In the rabbit corneas, similar acute changes were noted. By 3 weeks, epithelial hyperplasia and stromal contraction were present. Wound healing in the rabbit corneas included repair of the epithelial attachment complex, keratocyte activation, synthesis of type I collagen, partial restoration of stromal keratan sulfate and type VI collagen, and retrocorneal membrane formation. Compared to 10-pulse treatments, 5-pulse treatments produced less acute tissue injury and had more rapid restoration of normal stromal architecture. CONCLUSION: Noncontact LTK produces acute epithelial and stromal tissue changes and in rabbit corneas stimulates a brisk wound healing response. These changes could contribute to postoperative regression of induced refractive correction. Further work is required to determine if reductions in the magnitude of acute tissue injury and induced wound healing response will enhance the efficacy and stability of LTK. Images FIGURE 1A FIGURE 1B FIGURE 2A FIGURE 2B FIGURE 3A FIGURE 3B FIGURE 4A FIGURE 4B FIGURE 4C FIGURE 4D FIGURE 5A FIGURE 5B FIGURE 5C FIGURE 5D FIGURE 6A FIGURE 6B FIGURE 6C FIGURE 6D FIGURE 7A FIGURE 7B FIGURE 8A FIGURE 8B FIGURE 8C FIGURE

  7. Factors Affecting De Novo Urinary Retention after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Kim, Sung Han; Yoo, Changwon; Choo, Minsoo; Paick, Jae-Seung; Oh, Seung-June

    2014-01-01

    Objective Patients can experience urinary retention (UR) after Holmium laser enucleation of the prostate (HoLEP) that requires bladder distension during the procedure. The aim of this retrospective study is to identify factors affecting the UR after HoLEP. Materials and Methods 336 patients, which underwent HoLEP for a symptomatic benign prostatic hyperplasia between July 2008 and March 2012, were included in this study. Urethral catheters were routinely removed one or two days after surgery. UR was defined as the need for an indwelling catheter placement following a failure to void after catheter removal. Demographic and clinical parameters were compared between the UR (n = 37) and the non-urinary retention (non-UR; n = 299) groups. Results The mean age of patients was 68.3 (±6.5) years and the mean operative time was 75.3 (±37.4) min. Thirty seven patients (11.0%) experienced a postoperative UR. UR patients voided catheter free an average of 1.9 (±1.7) days after UR. With regard to the causes of UR, 24 (7.1%) and 13 (3.9%) patients experienced a blood clot-related UR and a non-clot related UR respectively. Using multivariate analysis (p<0.05), we found significant differences between the UR and the non-UR groups with regard to a morcellation efficiency (OR 0.701, 95% CI 0.498–0.988) and a bleeding-related complication, such as, a reoperation for bleeding (OR 0.039, 95% CI 0.004–0.383) or a transfusion (OR 0.144, 95% CI 0.027–0.877). Age, history of diabetes, prostate volume, pre-operative post-void residual, bladder contractility index, learning curve, and operative time were not significantly associated with the UR (p>0.05). Conclusions De novo UR after HoLEP was found to be self-limited and it was not related to learning curve, patient age, diabetes, or operative time. Efficient morcellation and careful control of bleeding, which reduces clot formation, decrease the risk of UR after HoLEP. PMID:24465454

  8. Single-frequency, single-polarization holmium-doped ZBLAN fiber laser

    NASA Astrophysics Data System (ADS)

    Zhu, X.; Zong, J.; Miller, A.; Wiersma, K.; Norwood, R. A.; Prasad, N. S.; Chavez-Pirson, A.; Peyghambarian, N.

    2013-02-01

    We present the performance of a single frequency, single-polarization holmium (Ho3+)-doped ZBLAN (ZrF4-BaF2-LaF3- AlF3-NaF) fiber laser at 1200 nm. This distributed Bragg reflector (DBR) fiber laser was developed by splicing a 22 mm long highly Ho3+-doped ZBLAN fiber to a pair of silica fiber Bragg gratings (FBG). The successful fusion splicing of silica fiber to ZBLAN fiber, with their very different melting temperatures, was accomplished by using NP Photonics proprietary splicing technique. The 3 mol% Ho3+-doped ZBLAN fiber had a core diameter of 6.5 μm and a cladding diameter of 125 μm. The threshold of this laser was seen to be about 260 mW, and when the pump power was 520 mW, the output power was about 10 mW. The efficiency of the 1200 nm single-frequency fiber laser, i.e. the ratio of the output power to the launched pump power, was about 3.8%. The linewidth of the 1200 nm single-frequency fiber laser was estimated to be about 100 kHz by comparing the measured frequency noise of the 1200 nm single-frequency fiber laser with that of 1 μm NP Photonics single-frequency fiber lasers whose linewidths have been measured to be in the 1- 10 kHz range. The relative intensity noise of this DBR all-fiber laser was measured to be < 110 dB/Hz at the relaxation oscillation peak and the polarization extinction ratio was measured to be > 19 dB. Due to its low phonon energy and long radiative lifetimes, rare-earth-doped ZBLAN allows various transitions that are typically terminated in silica glass, resulting in ultraviolet, visible, and infrared rare-earth doped ZBLAN lasers. Therefore, our results highlight the exciting prospect that the accessible wavelength range of single-frequency DBR fiber lasers can be expanded significantly by using rare-earth-doped ZBLAN fibers.

  9. Radiosynoviorthesis of knees by means of 166Ho-holmium-boro-macroaggregates.

    PubMed

    Kraft, Otakar; Kaspárek, Richard; Ullmann, Vojtech; Melichar, Frantisek; Kropácek, Martin; Mirzajevova, Marcela

    2007-04-01

    The aim of this study was to evaluate adverse and therapeutic effects of applicated holmium-boro-macroaggregates (HBMAs) in the radiosynoviorthesis (RSO) of knees in patients suffering from chronic synovitis. We started RSO of the knees by means of a new radiopharmaceutical (RF) HBMA in patients with gonarthrosis, rheumatoid arthritis, chronic synovitis, psoriatic arthritis, and gout arthropathy. Seventeen (17) intra-articular injections were performed in 15 patients who were receiving a mean activity of 972 MBq (range, 904-1057) of 166Ho-HBMA. Patient inclusion to the study followed a series of inclusion and exclusion criterions. The patients were hospitalized for 3 days. Side-effects were evaluated during their hospital stay and again after 6-8 weeks. Static scintigraphy of knee joints and measurements of blood radioactivity were performed. Therapeutic effects were evaluated after 6-8 weeks and at 6 months. In 2 hours and 2 days following the application, we proved, by means of knee and inguinal scintigraphy, only insignificant radiopharmaceutical leakage from the joint cavity to the inguinal lymph nodes in 4 patients. In the treated patients, no serious adverse effects occurred. Nine (9) patients were without complaints, 4 patients had slight knee exudation, and 2 patients had great exudation. Therapeutic effects were as follows: 2 patients were without pain, 9 were with lower pain, 3 were with the same pain, and 1 patient was with increased pain. Joint motion was improved in 7 patients, remained the same in 7 patients, and was impaired in 1 patient. Analgesics consumption was lower in 5 patients, the same in 9 patients, and greater in 1 patient. Knee exudation was absent in 2 patients, lower in 4 patients, the same in 6 patients, and greater in 3 patients. In 3 patients it was necessary to do surgical RSO. This RF can extend the range of clinically used radiopharmaceuticals for RSO and to supplement space between 90Y with high energy and 186Re with 169Er with

  10. Holmium Laser Enucleation of the Prostate is Safe for Patients Above 80 Years: A Prospective Study

    PubMed Central

    2016-01-01

    Purpose: To evaluate the effect of age on the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) for the treatment of symptomatic benign prostatic hyperplasia (BPH). Methods: A total of 579 patients underwent HoLEP procedure performed by a single surgeon (SJO) between December 2009 and May 2013. The perioperative and functional outcomes of patients in the age groups of 50–59 (group A, n=44), 60–69 (group B, n=253), 70–79 (group C, n=244), and ≥80 years (group D, n=38) were compared. The Clavien-Dindo system was used to evaluate clinical outcomes. The International Prostate Symptom Score (IPSS), maximum urinary flow rate (Qmax), postvoid residual (PVR) urine volume, and urinary continence were used to assess functional outcomes. Results: In this study, the patients ≥80 years had significantly higher presence of hypertension (P=0.007), total prostate volumes (P=0.024), transitional zone volume (P=0.002), American Society of Anesthesiologists scores (P=0.006), urinary retention (P=0.032), and anticoagulation use (P=0.008) at preoperative period. Moreover, the mean values of operation time, enucleation time, morcellation time, and enucleation weight were higher in group D compared with other group patients (P=0.002, P=0.010, P<0.01, and P=0.009, respectively). Patients aged ≥80 years had a longer hospital stay time (2.9±1.8 days) than other groups (group A, 2.3±0.7 days; group B, 2.3±0.7 days vs. group C, 2.4±0.7 days; P=0.001). All groups were similar in regard to the incidence of complications (Clavien-Dindo grade) post operatively (P>0.05). All the patients in the present study showed improvement in functional outcomes after HoLEP. By the sixth month, there were no significant differences in IPSS, quality of life, Qmax, and PVR among the groups (P>0.05). Conclusions: Compared with younger patients, the patients aged ≥80 years had a similar overall morbidity and 6-month functional outcomes of HoLEP. HoLEP is a safe and

  11. New ternary praseodymium germanides

    SciTech Connect

    Fedyna, M.F.; Pecharskii, V.K.; Bodak, O.I.

    1987-09-01

    Using the powder method (DRON-2.0 diffractometer; Fe K/sub ..cap alpha../ radiation; theta/2theta recording method, sin theta/sub max//lambda = 5 nm/sup -1/), the crystal structure of the ternary compounds Pr/sub 1-x/(NiGe)/sub 13/ (x = 0.24), Pr/sub 3/Ni/sub 4/Ge/sub 4/, Pr/sub 1-x/(CoGe)/sub 13/ (x = 0.31), Pr/sub 2/Co/sub 3/Ge/sub 5/, and PrFe/sub 1-x/Ge/sub 3/ (x = 0.46) were determined. The germanides P/sub 1-x/(NiGe)/sub 13/ and Pr/sub 1-x/(NiGe)/sub 13/ belong to the structural type of CeNi/sub 8.5/Si/sub 4.5/ and the ternary compounds Pr/sub 3/Ni/sub 4/Ge/sub 4/, Pr/sub 2/Co/sub 3/Ge/sub 5/, and PrFe/sub 1-x/Ge/sub 3/ crystallize in the structural types of U/sub 3/Ni/sub 4/Si/sub 4/, U/sub 2/Co/sub 3/Si/sub 5/, and BaNiSn/sub 3/. During investigations of the equilibrium phase diagrams of the systems Pr-/Fe, Co, Ni/-Ge, new ternary compounds were discovered, viz., Pr/sub 1-x/(NiGe)/sub 13/ (X = 0.24), Pr/sub 3/Ni/sub 4/Ge/sub 4/, Pr/sub 1-x/(CoGe)/sub 13/ (x = 0.31), Pr/sub 2/Co/sub 3/Ge/sub 5/, PrFe/sub 1-x/Ge/sub 3/ (x = 0.46).

  12. Neutron diffraction and electrical transport studies on the incommensurate magnetic phase transition in holmium at high pressures

    SciTech Connect

    Thomas, Sarah; Uhoya, Walter; Tsoi, Georgiy; Wenger, Lowell E; Vohra, Yogesh; Chesnut, Gary Neal; Weir, S. T.; Tulk, Christopher A; Moreira Dos Santos, Antonio F

    2012-01-01

    Neutron diffraction and electrical transport measurements have been made on the heavy rare earth metal holmium at high pressures and low temperatures in order to elucidate its transition from a paramagnetic (PM) to a helical antiferromagnetic (AFM) ordered phase as a function of pressure. The electrical resistance measurements show a change in the resistance slope as the temperature is lowered through the antiferromagnetic Neel temperature. The temperature of this antiferromagnetic transition decreases from approximately 122 K at ambient pressure at a rate of -4.9 K GPa(-1) up to a pressure of 9 GPa, whereupon the PM-to-AFM transition vanishes for higher pressures. Neutron diffraction measurements as a function of pressure at 89 and 110 K confirm the incommensurate nature of the phase transition associated with the antiferromagnetic ordering of the magnetic moments in a helical arrangement and that the ordering occurs at similar pressures as determined from the resistance results for these temperatures.

  13. Holmium-doped 2.1 μm waveguide chip laser with an output power > 1 W.

    PubMed

    Lancaster, D G; Stevens, V J; Michaud-Belleau, V; Gross, S; Fuerbach, A; Monro, T M

    2015-12-14

    We demonstrate the increasing applicability of compact ultra-fast laser inscribed glass guided-wave lasers and report the highest-power glass waveguide laser with over 1.1 W of output power in monolithic operation in the short-infrared near 2070 nm achieved (51% incident slope efficiency). The holmium doped ZBLAN chip laser is in-band pumped by a 1945 nm thulium fiber laser. When operated in an extended-cavity configuration, over 1 W of output power is realized in a linearly polarized beam. Broad and continuous tunability of the extended-cavity laser is demonstrated from 2004 nm to 2099 nm. Considering its excellent beam quality of M² = 1.08, this laser shows potential as a flexible master oscillator for single frequency and mode-locking applications. PMID:26699055

  14. Thulium/holmium-doped fiber laser passively mode locked by black phosphorus nanoplatelets-based saturable absorber.

    PubMed

    Yu, Hao; Zheng, Xin; Yin, Ke; Cheng, Xiang'ai; Jiang, Tian

    2015-12-01

    By coupling black phosphorus (BP) nanoplatelets (NPs) with a fiber-taper evanescent light field, a saturable absorber (SA) based on the BP NPs has been successfully fabricated and used in a thulium/holmium-doped fiber laser as the mode locker. The SA had a modulation depth of ∼9.8% measured at 1.93 μm. A stable mode-locking operation at 1898 nm was achieved with a pulse width of 1.58 ps and a fundamental mode-lock repetition rate of 19.2 MHz. By increasing the pump intensity, phenomena of multi-pulsing operations, including harmonic mode-locked states and soliton bunches, were obtained in the experiment, showing that the BP NPs possess an ultrafast optical response time. This work suggests that the BP NPs-based SA is potentially useful for ultrashort, pulsed laser operations in the eye-safe region of 2 μm. PMID:26836690

  15. Holmium YLF amplifier performance and the prospects for multi-Joule energies using diode-laser pumping

    NASA Technical Reports Server (NTRS)

    Storm, Mark E.

    1993-01-01

    Laser studies were performed to examine the amplifier characteristics of holmium-doped yttrium lithium fluoride (YLF) at 300 K. An inversion ratio of 0.37 was reached resulting in a measured small-signal gain coefficient of 0.50/cm. In a flashlamp pumping experiment, an output energy of 240 mJ was achieved for 38.5 mJ of input energy resulting in a large gain of 6.2. An amplifier model was developed for diode laser pumping and adapted to consider this flashlamp-pumped case. There is good agreement between the theory and experiment. Multipass amplifier calculations using the model suggest that the Ho: Tm: YLF laser crystal can support a 12 percent electrical to optical efficiency at 300 K even in the presence of upconversion.

  16. [Investigation of changes in sexual and ejaculatory functions after holmium laser enucleation of the prostate (HoLEP)].

    PubMed

    Ishikawa, Ryuta; Shitara, Toshiya; Hirayama, Takahiro; Wakatabe, Yoji; Dobashi, Masato; Sugita, Yoshiko; Kubo, Seiichi; Fujita, Tetsuo; Iwamura, Masatsugu; Baba, Shiro

    2014-06-01

    Changes in sexual function and ejaculatory function in patients who had undergone holmium laser enucleation of the prostate (HoLEP) were investigated using questionnaires. In this study, 77 patients on whom HoLEP was performed at our department from July 2010 to December 2010 were included. Of the 77 patients, the number of patients who could achieve an erection increased from 36 (46.8%) preoperatively to 52 (67.5%) postoperatively after HoLEP. Although postoperative ejaculatory dysfunction was found in 38 (73%) of 52 patients, 47 (90%) experienced orgasms, regardless of ejaculation, which is a high rate. With respect to ejaculatory satisfaction, patients who experienced an ejaculation had significantly higher satisfaction levels than those who did not. These results suggest that changes in postoperative ejaculatory function might affect satisfaction levels of ejaculation. PMID:25001640

  17. Ex vivo pyelotomy, nephroscopy and holmium laser lithotripsy of a staghorn stone in a donor kidney prior to renal transplant

    PubMed Central

    Janczak, Dariusz; Bolanowska, Barbara; Jankowski, Paweł; Dorobisz, Tadeusz; Dorobisz, Karolina; Chabowski, Mariusz; Janczak, Dawid

    2015-01-01

    This case report presents the diagnostic and treatment procedures of stone removal from the kidney of a 67-year-old donor, the transplantation of the kidney to a 65-year-old recipient, and the postoperative course until the end of hospitalization. Computed tomography performed before collecting the organ showed a staghorn stone in the renal pelvis and lower calyces in the right donor kidney. The stones were removed ex-vivo using a rigid ureteroscope and a holmium laser prior to transplantation. Then the organ was transplanted to the left iliac fossa of a 65-year-old man with end-stage renal failure. The authors think there is a possibility of increasing the kidney pool, by using organs containing large calculi. In such cases stones should be removed before the operation and the patient should be monitored regularly, especially in the first months after the transplant. PMID:26240630

  18. Nanomaterials for photonic applications: Silica self-assembly and erbium titanate activation

    NASA Astrophysics Data System (ADS)

    Lee, Cheol

    , Erbium Titanate (ETO) nanopowders with a well defined crystallinity were fabricated by using complexed precursors of erbium and titanium. The relatively strong infrared fluorescence was obtained for pyrochlore ETO (Er 2Ti2O7) nanopowders (≈40 nm), whose emission spectrum centered around 1530 nm with a FWHM of 70 nm. The anticipated optical property changes in terms of phonon energy were in good agreement with Er fluorescence and photoluminescence decay measurements in this materials. This study indicated that pyrochlore nanocrystal will serve a good host leading to efficient erbium emission at 1.53 mum.

  19. Radiotherapeutic bandage based on electrospun polyacrylonitrile containing holmium-166 iron garnet nanoparticles for the treatment of skin cancer.

    PubMed

    Munaweera, Imalka; Levesque-Bishop, Daniel; Shi, Yi; Di Pasqua, Anthony J; Balkus, Kenneth J

    2014-12-24

    Radiation therapy is used as a primary treatment for inoperable tumors and in patients that cannot or will not undergo surgery. Radioactive holmium-166 ((166)Ho) is a viable candidate for use against skin cancer. Nonradioactive holmium-165 ((165)Ho) iron garnet nanoparticles have been incorporated into a bandage, which, after neutron-activation to (166)Ho, can be applied to a tumor lesion. The (165)Ho iron garnet nanoparticles ((165)HoIG) were synthesized and introduced into polyacrylonitrile (PAN) polymer solutions. The polymer solutions were then electrospun to produce flexible nonwoven bandages, which are stable to neutron-activation. The fiber mats were characterized using scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis and inductively coupled plasma mass spectrometry. The bandages are stable after neutron-activation at a thermal neutron-flux of approximately 3.5 × 10(12) neutrons/cm(2)·s for at least 4 h and 100 °C. Different amounts of radioactivity can be produced by changing the amount of the (165)HoIG nanoparticles inside the bandage and the duration of neutron-activation, which is important for different stages of skin cancer. Furthermore, the radioactive bandage can be easily manipulated to irradiate only the tumor site by cutting the bandage into specific shapes and sizes that cover the tumor prior to neutron-activation. Thus, exposure of healthy cells to high energy β-particles can be avoided. Moreover, there is no leakage of radioactive material after neutron activation, which is critical for safe handling by healthcare professionals treating skin cancer patients. PMID:25396281

  20. [Experimental liver and kidney surgery with CO2, CO, holmium, and neodym lasers. Cutting effect, hemostasis, histopathology, and healing (author's transl)].

    PubMed

    Karbe, E; Königsmann, G; Beck, R

    1980-01-01

    Various laser devices (CO2, CO, Nd: YAG, and holmium: YAG lasers) have been used on pig livers and on dog kidneys for comparison with conventional surgical instruments (electroscalpel, cryoscalpel, and scalpel). CO2 and CO lasers caused the least tissue damage, followed by the holmium laser; severe damage was caused by the Nd: YAG laser. The order was reverse for coagulative effect. The conventional reference instruments showed a weaker hemostatic effect. Surfaces cut by laser healed in four to eight weeks without complications. Remnants of charred tissue in various quantities could still be detected after eight weeks in all cases where CO2, CO, and Nd: YAG lasers had been used. This obviously did not affect scar formation. PMID:6779065

  1. 70-fs mode-locked erbium-doped fiber laser with topological insulator.

    PubMed

    Liu, Wenjun; Pang, Lihui; Han, Hainian; Tian, Wenlong; Chen, Hao; Lei, Ming; Yan, Peiguang; Wei, Zhiyi

    2016-01-01

    Femtosecond optical pulses have applications in optical communication, astronomical frequency combs, and laser spectroscopy. Here, a hybrid mode-locked erbium-doped fiber (EDF) laser with topological insulator (TI) is proposed, for the first time to our best knowledge. The pulsed laser deposition (PLD) method is employed to fabricate the fiber-taper TI saturable absorber (TISA). By virtue of the fiber-taper TISA, the hybrid EDF laser is passively mode-locked using the nonlinear polarization evolution (NPE), and emits 70 fs pulses at 1542 nm, whose 3 dB spectral width is 63 nm with a repetition rate and transfer efficiency of 95.4 MHz and 14.12%, respectively. Our experiments indicate that the proposed hybrid mode-locked EDF lasers have better performance to achieve shorter pulses with higher power and lower mode-locking threshold in the future. PMID:26813439

  2. 70-fs mode-locked erbium-doped fiber laser with topological insulator

    NASA Astrophysics Data System (ADS)

    Liu, Wenjun; Pang, Lihui; Han, Hainian; Tian, Wenlong; Chen, Hao; Lei, Ming; Yan, Peiguang; Wei, Zhiyi

    2016-01-01

    Femtosecond optical pulses have applications in optical communication, astronomical frequency combs, and laser spectroscopy. Here, a hybrid mode-locked erbium-doped fiber (EDF) laser with topological insulator (TI) is proposed, for the first time to our best knowledge. The pulsed laser deposition (PLD) method is employed to fabricate the fiber-taper TI saturable absorber (TISA). By virtue of the fiber-taper TISA, the hybrid EDF laser is passively mode-locked using the nonlinear polarization evolution (NPE), and emits 70 fs pulses at 1542 nm, whose 3 dB spectral width is 63 nm with a repetition rate and transfer efficiency of 95.4 MHz and 14.12%, respectively. Our experiments indicate that the proposed hybrid mode-locked EDF lasers have better performance to achieve shorter pulses with higher power and lower mode-locking threshold in the future.

  3. 70-fs mode-locked erbium-doped fiber laser with topological insulator

    PubMed Central

    Liu, Wenjun; Pang, Lihui; Han, Hainian; Tian, Wenlong; Chen, Hao; Lei, Ming; Yan, Peiguang; Wei, Zhiyi

    2016-01-01

    Femtosecond optical pulses have applications in optical communication, astronomical frequency combs, and laser spectroscopy. Here, a hybrid mode-locked erbium-doped fiber (EDF) laser with topological insulator (TI) is proposed, for the first time to our best knowledge. The pulsed laser deposition (PLD) method is employed to fabricate the fiber-taper TI saturable absorber (TISA). By virtue of the fiber-taper TISA, the hybrid EDF laser is passively mode-locked using the nonlinear polarization evolution (NPE), and emits 70 fs pulses at 1542 nm, whose 3 dB spectral width is 63 nm with a repetition rate and transfer efficiency of 95.4 MHz and 14.12%, respectively. Our experiments indicate that the proposed hybrid mode-locked EDF lasers have better performance to achieve shorter pulses with higher power and lower mode-locking threshold in the future. PMID:26813439

  4. Stable single-longitudinal-mode erbium-doped fiber laser with dual-ring structure

    NASA Astrophysics Data System (ADS)

    Yeh, Chien-Hung; Chen, Jhih-Yu; Chen, Hone-Zhang; Chow, Chi-Wai

    2016-01-01

    In this paper, we propose and demonstrate experimentally a stable erbium-doped fiber (EDF) laser with single-longitudinal-mode (SLM) output by employing dual-ring structure. By using the multiple ring architecture, the densely spaced longitudinal modes would be suppressed and generated a SLM lasing output. In the measurement, the wavelength can be tuned in the wavelengths of 1530.0-1560.0 nm. And the measured output powers and side-mode suppression ratios (SMSRs) are between 5.2 and 14.1 dBm and 30.4 and 39.8 dB, respectively. In addition, the output stabilities of wavelength and power in proposed fiber laser have also been discussed.

  5. [INVITED] Multiwavelength operation of erbium-doped fiber-ring laser for temperature measurements

    NASA Astrophysics Data System (ADS)

    Diaz, S.; Lopez-Amo, M.

    2016-04-01

    In this work, simultaneous lasing at up to eight wavelengths is demonstrated in a multi-wavelength erbium-doped fiber ring laser previously reported. This is achieved by introducing a feedback fiber loop in a fiber ring cavity. Eight-wavelength laser emission lines were obtained simultaneously in single-longitudinal mode operation showing a power instability lower than 0.8 dB, and an optical signal-to-noise ratio higher than 42 dB for all the emitted wavelengths. The fiber Bragg gratings give this source the possibility to be also used as sensor-network multiplexing scheme. The application of this system for remote temperature measurements has been demonstrated obtaining good time stability results.

  6. Amplification and noise properties of an erbium-doped multicore fiber amplifier

    NASA Astrophysics Data System (ADS)

    Abedin, K. S.; Taunay, T. F.; Fishteyn, M.; Yan, M. F.; Zhu, B.; Fini, J. M.; Monberg, E. M.; Dimarcello, F. V.; Wisk, P. W.

    2011-08-01

    A multicore erbium-doped fiber (MC-EDF) amplifier for simultaneous amplification in the 7-cores has been developed, and the gain and noise properties of individual cores have been studied. The pump and signal radiation were coupled to individual cores of MC-EDF using two tapered fiber bundled (TFB) couplers with low insertion loss. For a pump power of 146 mW, the average gain achieved in the MC-EDF fiber was 30 dB, and noise figure was less than 4 dB. The net useful gain from the multicore-amplifier, after taking into consideration of all the passive losses, was about 23-27 dB. Pump induced ASE noise transfer between the neighboring channel was negligible.

  7. Exploring Few- and Many-Body Dipolar Quantum Phenomena with Ultracold Erbium Atoms

    NASA Astrophysics Data System (ADS)

    Ferlaino, Francesca

    2016-05-01

    Given their strong magnetic moment and exotic electronic configuration, rare-earth atoms disclose a plethora of intriguing phenomena in ultracold quantum physics with dipole-dipole interaction. Here, we report on the first degenerate Fermi gas of erbium atoms, based on direct cooling of identical fermions via dipolar collisions. We reveal universal scattering laws between identical dipolar fermions close to zero temperature, and we demonstrate the long-standing prediction of a deformed Fermi surface in dipolar gas. Finally, we present the first experimental study of an extended Bose-Hubbard model using bosonic Er atoms in a three-dimensional optical lattice and we report on the first observation of nearest-neighbor interactions.

  8. Accelerated two-wave mixing response in erbium-doped fibers with saturable optical absorption

    NASA Astrophysics Data System (ADS)

    Hernandez, Eliseo; Stepanov, Serguei; Plata Sanchez, Marcos

    2016-08-01

    The contribution of the spatially uniform variation of average optical absorption to the dynamics of the transient two-wave mixing (TWM) response is considered. It is shown theoretically and confirmed experimentally that this transient effect, via dynamic population gratings in erbium-doped fibers (EDFs) can ensure a response nearly two times faster in such gratings as compared to the growth rate of fluorescence uniformly excited under similar conditions, and can also result in an additional overshot in the tail of the TWM response. This additional ‘accelerating’ contribution is of even type, and does not influence the odd transient TWM response for the refractive index component of such gratings in the EDFs reported earlier. It is also shown that this effect can be utilized to monitor the formation of the dynamic grating with an auxiliary probe wave of the essentially different non-Bragg wavelength.

  9. Timing stability enhancement of an Erbium Doped mode locked Fiber Laser using SESAM mirror

    NASA Astrophysics Data System (ADS)

    Afifi, G.; Khedr, M. Atta; Badr, Y.; Danailov, M.; Sigalotti, P.; Cinquegrana, P.; Alsous, M. B.; Galaly, A. R.

    2016-05-01

    We report on an examination of pulse timing stability of a home built Erbium Doped Fiber Laser (EDFL) passively mode locked via nonlinear polarization rotation by inserting semiconductor saturable absorber mirror (SESAM) in laser cavity. A very low root mean square (RMS) timing jitter (less than 27 fsec) and faster self-starting mode locking have been established. In order to get clear, low noise signal for time resolving measurements, synchronization of EDFL laser with an external high precision electronic oscillator have been established. Subsequently, it is synchronized and optically cross-correlated with a Ti:Sapphire laser source (Micra). The measured relative timing jitter was found to be less than 65 fsec. In this way, the two, well synchronized Ti:Sapphire and EDFL laser pulses prove to be a powerful tool for time resolving measurements.

  10. Temperature dependences of the photoluminescence intensities of centers in silicon implanted with erbium and oxygen ions

    SciTech Connect

    Sobolev, N. A. Shtel’makh, K. F.; Kalyadin, A. E.; Shek, E. I.

    2015-12-15

    Low-temperature photoluminescence in n-Cz-Si after the implantation of erbium ions at an elevated temperature and subsequent implantation of oxygen ions at room temperature is studied. So-called X and W centers formed from self-interstitial silicon atoms, H and P centers containing oxygen atoms, and Er centers containing Er{sup 3+} ions are observed in the photoluminescence spectra. The energies of enhancing and quenching of photoluminescence for these centers are determined. These energies are determined for the first time for X and H centers. In the case of P and Er centers, the values of the energies practically coincide with previously published data. For W centers, the energies of the enhancing and quenching of photoluminescence depend on the conditions of the formation of these centers.

  11. Low-threshold and multi-wavelength Q-switched random erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Wang, Simin; Lin, Wei; Chen, Weicheng; Li, Can; Yang, Changsheng; Qiao, Tian; Yang, Zhongmin

    2016-03-01

    We demonstrate a low-threshold and multi-wavelength Q-switched random fiber laser with erbium-doped fiber as the gain medium and Rayleigh scattering as the randomly distributed feedback. Q-switched pulses are generated with threshold as low as 27 mW by combining random cavity resonances and the Q-value modulation effect induced by stimulated Brillouin scattering. The repetition rate is typically on the kilohertz scale with rms timing jitter of <5.5% and rms amplitude fluctuation of <30%. Raman Stokes emissions up to the third order are observed with an overall energy of nearly 42% of the pulse output, which may open an avenue for applications requiring multiple wavelengths.

  12. Submicrojoule femtosecond erbium-doped fibre laser for the generation of dispersive waves at submicron wavelengths

    SciTech Connect

    Kotov, L V; Koptev, M Yu; Anashkina, E A; Muravyev, S V; Andrianov, A V; Kim, A V; Bubnov, M M; Likhachev, M E; Ignat'ev, A D; Lipatov, D S; Gur'yanov, A N

    2014-05-30

    We have demonstrated a femtosecond erbium-doped fibre laser system built in the master oscillator/power amplifier (MOPA) approach. The final amplifier stage utilises a specially designed large mode area active fibre cladding-pumped by multimode laser diodes. The system is capable of generating submicrojoule pulses at a wavelength near 1.6 μm. We have obtained 530-fs pulses with an energy of 400 nJ. The output of the system can be converted to wavelengths shorter than 1 μm through the generation of dispersive waves in passive nonlinear fibre. We have obtained ultra-short 7-nJ pulses with a spectral width of ∼100 nm and a centre wavelength of 0.9 μm, which can be used as a seed signal in parametric amplifiers in designing petawatt laser systems. (lasers)

  13. Stability of short, single-mode erbium-doped fiber lasers

    SciTech Connect

    Svalgaard, M.; Gilbert, S.L.

    1997-07-01

    We conducted a detailed study of the stability of short, erbium-doped fiber lasers fabricated with two UV-induced Bragg gratings written into the doped fiber. We find that the relative intensity noise of single-longitudinal-mode fiber grating lasers is approximately 3 orders of magnitude lower than that of a single-frequency 1.523-{mu}m helium-neon laser. The frequency noise spectrum contains few resonances, none of which exceeds 0.6 kHz/Hz{sup 1/2} rms; the integrated rms frequency noise from 50 Hz to 63 kHz is 36 kHz. We also demonstrate a simple method for monitoring the laser power and number of oscillating modes during laser fabrication. {copyright} 1997 Optical Society of America

  14. Q-switched Erbium-doped fiber laser using MoSe2 as saturable absorber

    NASA Astrophysics Data System (ADS)

    Ahmad, H.; Suthaskumar, M.; Tiu, Z. C.; Zarei, A.; Harun, S. W.

    2016-05-01

    A Q-switched Erbium-doped fiber laser by using MoSe2 thin film as saturable absorber is experimentally demonstrated. The bulk MoSe2 is processed into few layer MoSe2 based on liquid phase exfoliation technique, and further fabricated into thin film by using polyvinyl alcohol polymer. Q-switching operation is obtained from pump power range of 22.4-102.0 mW. The pulse repetition rate shows an increasing trend from 16.9 kHz to 32.8 kHz, whereas the pulse width exhibits a decreasing trend from 59.1 μs to 30.4 μs. The highest pulse energy of 57.9 nJ is obtained at pump power of 102.0 mW.

  15. High optical carrier-suppression characteristics of Brillouin/erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, Mo; Zhou, Huijuan; Meng, Zhou

    2011-11-01

    A Brillouin/erbium fiber laser (BEFL) of 25km single-mode fiber is constructed, and its characteristics of optical carrier suppression are measured and analyzed. Light wave modulated by an electro-optic intensity modulator (EOIM) with 11GHz microwave frequency is adopted as the testing light. As much as 32 dB optical carrier-suppression ratio is achieved at 112mW of 980nm pump power inside the BEFL. Meanwhile, the sideband powers remain nearly unchanged in the process. Moreover, the carrier-suppression ratio is precisely controllable by tuning the 980nm pump power in the BEFL. These optical carrier-suppression characteristics promise significant applications of such a technique not only to distributed Brillouin optical fiber sensing based on EOIM but also to microwave photonic signal processing.

  16. Broadly tunable multiwavelength Brillouin-erbium fiber laser using a twin-core fiber coupler

    NASA Astrophysics Data System (ADS)

    Peng, Wanjing; Yan, Fengping; Li, Qi; Liu, Shuo; Tan, Siyu; Feng, Suchun; Feng, Ting

    2014-07-01

    A tunable multiwavelength Brillouin-erbium fiber laser (MW-BEFL) using a twin-core fiber (TCF) coupler is proposed and demonstrated. The TCF coupler is formed by splicing a section of TCF between two single-mode fibers. By simply applying bending curvature on the TCF coupler, the peak net gain is shifted close to the Brillouin pump (BP), which has advantage for suppressing self-lasing cavity modes with low-BP-power injection. In this work, the dependency of the Stokes signals tuning range on the free spectral range (FSR) of TCF coupler is studied. It is also found that the tuning range of MW-BEFL can exceed the FSR of TCF coupler by adopting proper BP power and 980-nm pump power. Up to 40 nm tuning range of MW-BEFL in the absence of self-lasing cavity modes is achieved.

  17. Optical and spectroscopic properties of soda lime alumino-silicate glasses doped with erbium and silver

    NASA Astrophysics Data System (ADS)

    Carmo, A. P.; Bell, M. J. V.; Da Costa, Z. M.; Anjos, V.; Barbosa, L. C.; Chillcce, E. F.; Giehl, J. M.; Pontuschka, W. M.

    2011-10-01

    Spectroscopic properties of Ag/Er co-doped soda lime silicate glasses have been studied with the aim of assessing the effective role of silver as a sensitizer for erbium. Changes in spectroscopic properties of Er 3+ as a function of silver addition to the base composition have been measured. Transmission electron microscopy (TEM), absorption as well as photoluminescence measurements in the visible and infrared spectral region, particularly 4I 13/2 → 4I 15/2 transition of the Er 3+ ion were performed; excitation wavelengths in the range from 325 to 808 nm were used. Enhancement of the Er 3+ luminescence at 1.54 μm was observed when Ag was added.

  18. Magnetic behavior of erbium-zinc-borate glasses and glass ceramics

    SciTech Connect

    Borodi, G.; Pascuta, P.; Bosca, M.; Pop, V.; Stefan, R.; Tetean, R.; Radulescu, D.

    2013-11-13

    Glasses of the system (Er{sub 2}O{sub 3}){sub x}⋅(B{sub 2}O{sub 3}){sub (60−x)}⋅(ZnO){sub 40} (3 ≤ x ≤ 15 mol%) were prepared by conventional melt quenching and subsequently converted to glass ceramics by heat treatment of glass samples at 860 °C for 2 h. The magnetic behaviour of the studied glasses and glass ceramics were investigated using a vibrating sample magnetometer (VSM) and a Faraday-type magnetic balance. Magnetic data show that erbium ions are involved in negative superexchange interactions in all the investigated samples, being antiferromagnetically coupled. For all studied samples the experimental values obtained for the effective magnetic moments are lower than the value corresponding to free Er{sup 3+} ions and decrease with the increasing of Er{sub 2}O{sub 3} content. The decrease is more pronounced in heat treated samples than untreated ones.

  19. Amplification and noise properties of an erbium-doped multicore fiber amplifier.

    PubMed

    Abedin, K S; Taunay, T F; Fishteyn, M; Yan, M F; Zhu, B; Fini, J M; Monberg, E M; Dimarcello, F V; Wisk, P W

    2011-08-15

    A multicore erbium-doped fiber (MC-EDF) amplifier for simultaneous amplification in the 7-cores has been developed, and the gain and noise properties of individual cores have been studied. The pump and signal radiation were coupled to individual cores of MC-EDF using two tapered fiber bundled (TFB) couplers with low insertion loss. For a pump power of 146 mW, the average gain achieved in the MC-EDF fiber was 30 dB, and noise figure was less than 4 dB. The net useful gain from the multicore-amplifier, after taking into consideration of all the passive losses, was about 23-27 dB. Pump induced ASE noise transfer between the neighboring channel was negligible. PMID:21935033

  20. Microstructural, electrical and magnetic properties of erbium doped zinc oxide single crystals

    NASA Astrophysics Data System (ADS)

    Murmu, P. P.; Kennedy, J.; Ruck, B. J.; Rubanov, S.

    2015-11-01

    We report the structural, electrical and magnetic properties of erbium (Er) implanted zinc oxide (ZnO) single crystals. Rutherford backscattering and channeling results showed that the majority of Er atoms resided in Zn substitutional lattice sites. Annealing led to a fraction of Er atoms moving into random interstitial sites. Transmission electron microscopy micrographs revealed that doped Er atoms were located in the near-surface region, consistent with the results obtained from DYNAMIC-TRIM calculations. A non-linear Hall-voltage was observed near 100 K, which is associated with inhomogeneous transport in the material. The Er implanted and annealed ZnO exhibited persistent magnetic ordering to room temperature. Ferromagnetism was likely from the presence of intrinsic defects in ZnO, which mediates the magnetic ordering in Er implanted and annealed ZnO. [Figure not available: see fulltext.

  1. Passively mode-locked picosecond erbium-doped fiber lasers using multiple quantum well saturable absorbers

    NASA Astrophysics Data System (ADS)

    Hayduk, Michael J.; Krol, Mark F.; Pollock, Clifford R.; Teegarden, Kenneth J.; Wicks, Gary W.; Kaechele, Walter

    1998-07-01

    An experimental study of the mode-locking process in erbium- doped fiber lasers (EDFLs) operating at 1.55 micrometer using multiple quantum well saturable absorbers is described. The self-starting passively mode-locked laser was constructed in a Fabry-Perot configuration using the saturable absorber as the back reflector of the cavity. Picosecond pulses that ranged from 3.1 to 38.8 ps were generated using a series of saturable absorbers. The pulse widths were dependent upon the optical properties of the saturable absorber used as the mode- locking element as well as the dispersive elements contained within the cavity. The output power of the EDFL varied from 0.2 to 6.7 mW and was also dependent upon the saturable absorber used in the cavity.

  2. Stable double spacing multiwavelength Brillouin-Erbium doped fiber laser based on highly nonlinear fiber

    NASA Astrophysics Data System (ADS)

    Ahmad, B. A.; Al-Alimi, A. W.; Abas, A. F.; Harun, S. W.; Mahdi, M. A.

    2012-05-01

    A double frequency spaced multiwavelength Brillouin-Erbium doped fiber laser (BEDFL) with figure-of-eight cavity have been successfully developed and tested. Double frequency spacing is achieved by using a piece of 2 km of highly nonlinear fiber (HNLF) as a gain medium. Figure-of-eight configuration removes the odd order Stokes signals via a four-port circulator. Fifteen Stokes channels are simultaneously generated with a spacing of 0.154 nm that is around 20 GHz, when the Brillouin pump and 980 nm pump powers are fixed at the optimized values of 6 dBm and 40 mW, respectively. Fourteen anti stoke channels are also obtained, which are generated through four wave mixing (FWM) process in the laser cavity. The output is smooth triangular comb. The BEFL can also be tuned from 1526.5 to 1567.5 nm.

  3. Dispersion-compensating dual-mode optical fibers desirable for erbium-doped-fiber-amplified systems

    SciTech Connect

    Eguchi, Masashi

    2001-06-01

    A broadband dispersion-compensating dual-mode optical fiber with a double-layer profile core is proposed to compensate for positive dispersion in conventional single-mode optical fibers operating near 1.55 {mu}m. This wavelength band is suitable for erbium-doped-fiber-amplified systems. It is known that the first higher-order mode of dual-mode fibers exhibits large negative waveguide dispersion, and double-layer profile core fibers are dispersion-shifted fibers whose transmission and bending losses are lower than those of simple core-cladding dispersion-shifted fibers. Such advantages are attractive for commercial devices or modules. Here, a dispersion-compensating dual-mode fiber with a double-layer profile core that satisfies both low bending loss and broadband dispersion compensation is proposed. {copyright} 2001 Optical Society of America

  4. Physical properties of erbium implanted tungsten oxide filmsdeposited by reactive dual magnetron sputtering

    SciTech Connect

    Mohamed, Sodky H.; Anders, Andre

    2006-11-08

    Amorphous and partially crystalline WO3 thin films wereprepared by reactive dual magnetron sputtering and successively implantedby erbium ions with a fluence in the range from 7.7 x 1014 to 5 x 1015ions/cm2. The electrical and optical properties were studied as afunction of the film deposition parameters and the ion fluence. Ionimplantation caused a strong decrease of the resistivity, a moderatedecrease of the index of refraction and a moderate increase of theextinction coefficient in the visible and near infrared, while theoptical band gap remained almost unchanged. These effects could belargely ascribed to ion-induced oxygen deficiency. When annealed in air,the already low resistivities of the implanted samples decreased furtherup to 70oC, whereas oxidation, and hence a strong increase of theresistivity, was observed at higher annealing temperatures.

  5. Simple and efficient L-band erbium-doped fiber amplifiers for WDM networks

    NASA Astrophysics Data System (ADS)

    Choi, H. B.; Oh, J. M.; Lee, D.; Ahn, S. J.; Park, B. S.; Lee, S. B.

    2002-11-01

    The performance of L-band erbium-doped fiber amplifier (EDFA) of a simple structure with a fiber Bragg grating (FBG) was investigated. The injected C-band ASE by the FBG offers low-cost amplification and greatly improves the efficiency of the EDFA. There are 9 and 4 dB improvements with the FBG at 1587 nm, at low and high input, respectively. The flat gain of 18 dB, up to a total input of -5 dBm at 150 mW of 980 nm pump, is obtained over 30 nm with less than ±0.5 dB gain variations without any gain equalizer. The proposed EDFA provides a cost-effective solution for wavelength division multiplexing systems.

  6. High dispersive mirrors for erbium-doped fiber chirped pulse amplification system.

    PubMed

    Chen, Yu; Wang, Yanzhi; Wang, Linjun; Zhu, Meiping; Qi, Hongji; Shao, Jianda; Huang, Xiaojun; Yang, Sheng; Li, Chao; Zhou, Kainan; Zhu, Qihua

    2016-08-22

    We report on the development of near-infrared high dispersive mirrors (HDM) with a group delay dispersion (GDD) of -2000 fs2. A HDM pair based on one optimized result at two reference wavelengths (1550 nm and 1560 nm) can reduce the total oscillation of the GDD effectively in the wavelength range of 1530-1575 nm. This HDM pair is designed and fabricated in a single coating run by means of the nonuniformity in film deposition. For the first time, near-infrared HDMs with two different reference wavelengths have been successfully applied in an erbium-doped fiber chirped pulse amplification system for the compression of 4.73 ps laser pulses to 380 fs. PMID:27557259

  7. Magnetic and structural phase transitions in erbium at low temperatures and high pressures

    SciTech Connect

    Thomas, Sarah A.; Tsoi, Georgiy M.; Wenger, Lowell E.; Vohra, Yogesh K.

    2012-02-07

    Electrical resistance and crystal structure measurements have been carried out on polycrystalline erbium (Er) at temperatures down to 10 K and pressures up to 20 GPa. An abrupt change in the slope of the resistance is observed with decreasing temperature below 84 K, which is associated with the c-axis modulated (CAM) antiferromagnetic (AFM) ordering of the Er moments. With increasing pressure the temperature of the resistance slope change and the corresponding AFM ordering temperature decrease until vanishing above 10.6 GPa. The disappearance of the slope change in the resistance occurs at similar pressures where the hcp structural phase of Er is transformed to a nine-layer {alpha}-Sm structural phase, as confirmed by our high-pressure synchrotron x-ray diffraction studies. These results suggest that the disappearance in the AFM ordering of Er moments is strongly correlated to the structural phase transition at high pressures and low temperatures.

  8. Glassy behavior in a one-dimensional continuous-wave erbium-doped random fiber laser

    NASA Astrophysics Data System (ADS)

    Gomes, Anderson S. L.; Lima, Bismarck C.; Pincheira, Pablo I. R.; Moura, André L.; Gagné, Mathieu; Raposo, Ernesto P.; de Araújo, Cid B.; Kashyap, Raman

    2016-07-01

    The photonic analog of the paramagnetic to spin-glass phase transition in disordered magnetic systems, signaled by the phenomenon of replica symmetry breaking, has been reported using random lasers as the photonic platform. We report here a demonstration of replica symmetry breaking in a one-dimensional photonic system consisting of an erbium-doped random fiber laser operating in the continuous-wave regime. The system is based on a unique random fiber grating system which plays the role of random scattering, providing the disordered feedback mechanism. The clear transition from a photonic paramagnetic to a photonic spin-glass phase, characterized by the Parisi overlap parameter, was verified and indicates the glassy random-fiber-laser behavior.

  9. Stable and tunable self-seeded multiwavelength Brillouin-erbium fiber laser with higher OSNR

    NASA Astrophysics Data System (ADS)

    Zou, Hui; Yang, Ruilan; Shen, Xiao; Wei, Wei

    2016-07-01

    A stable and tunable self-seeded multiwavelength Brillouin-erbium fiber laser (BEFL) is designed and demonstrated based on a Single-Mode-Multimode-Single-Mode (SMS) fiber filter. The SMS filter is fabricated by splicing a 15 cm long multimode fiber between two single mode fibers. The self-excited Brillouin pump is internally achieved by cascaded stimulated Brillouin scattering (SBS) in the single mode fiber. By applying axial strain (from 0 to 466.7 μɛ) to the SMS filter with the same step of 66.7 μɛ , the multiwavelength of the output laser is tuned from 1553.58 to 1559.79 nm correspondingly, and the tunable range is 6.21 nm. The generation of up to 16 Brillouin Stokes wavelengths with 30 dB optical signal to noise ratio (OSNR) are obtained.

  10. Frequency spacing switchable multiwavelength Brillouin erbium fiber laser utilizing cascaded Brillouin gain fibers.

    PubMed

    Wang, Xiaorui; Yang, Yanfu; Liu, Meng; Yuan, Yijun; Sun, Yunxu; Gu, Yinglong; Yao, Yong

    2016-08-10

    A new hybrid Brillouin erbium fiber laser scheme that employs cascaded multiple Brillouin gain fibers in a ring cavity to realize multiwavelength laser output with switchable frequency spacing is proposed and experimentally investigated. The multiple frequency downshifting processes introduced by multiple stimulated Brillouin scattering (SBS) effects in one round-trip of the cavity make it possible to realize multiwavelength output with frequency spacing that is an integer multiple of the SBS frequency shifting. With two cascaded SBS fibers, the frequency spacing can be switched between single and double SBS frequency shifting by properly adjusting the Brillouin pump power. Multiwavelength outputs with triple or quadruple SBS frequency spacing are also demonstrated by employing three or four SBS gain fibers, respectively. PMID:27534498

  11. Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared.

    PubMed

    Washburn, Brian R; Diddams, Scott A; Newbury, Nathan R; Nicholson, Jeffrey W; Yan, Man F; Jørgensen, Carsten G

    2004-02-01

    A phase-locked frequency comb in the near infrared is demonstrated with a mode-locked, erbium-doped, fiber laser whose output is amplified and spectrally broadened in dispersion-flattened, highly nonlinear optical fiber to span from 1100 to >2200 nm. The supercontinuum output comprises a frequency comb with a spacing set by the laser repetition rate and an offset by the carrier-envelope offset frequency, which is detected with the standard f-to-2f heterodyne technique. The comb spacing and offset frequency are phase locked to a stable rf signal with a fiber stretcher in the laser cavity and by control of the pump laser power, respectively. This infrared comb permits frequency metrology experiments in the near infrared in a compact, fiber-laser-based system. PMID:14759041

  12. Magnetic behavior of erbium-zinc-borate glasses and glass ceramics

    NASA Astrophysics Data System (ADS)

    Borodi, G.; Pascuta, P.; Bosca, M.; Stefan, R.; Tetean, R.; Pop, V.; Radulescu, D.

    2013-11-01

    Glasses of the system (Er2O3)xṡ(B2O3)(60-x)ṡ(ZnO)40 (3 ≤ x ≤ 15 mol%) were prepared by conventional melt quenching and subsequently converted to glass ceramics by heat treatment of glass samples at 860 °C for 2 h. The magnetic behaviour of the studied glasses and glass ceramics were investigated using a vibrating sample magnetometer (VSM) and a Faraday-type magnetic balance. Magnetic data show that erbium ions are involved in negative superexchange interactions in all the investigated samples, being antiferromagnetically coupled. For all studied samples the experimental values obtained for the effective magnetic moments are lower than the value corresponding to free Er3+ ions and decrease with the increasing of Er2O3 content. The decrease is more pronounced in heat treated samples than untreated ones.

  13. Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre

    NASA Astrophysics Data System (ADS)

    Saglamyurek, Erhan; Jin, Jeongwan; Verma, Varun B.; Shaw, Matthew D.; Marsili, Francesco; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang

    2015-02-01

    The realization of a future quantum Internet requires the processing and storage of quantum information at local nodes and interconnecting distant nodes using free-space and fibre-optic links. Quantum memories for light are key elements of such quantum networks. However, to date, neither an atomic quantum memory for non-classical states of light operating at a wavelength compatible with standard telecom fibre infrastructure, nor a fibre-based implementation of a quantum memory, has been reported. Here, we demonstrate the storage and faithful recall of the state of a 1,532 nm wavelength photon entangled with a 795 nm photon, in an ensemble of cryogenically cooled erbium ions doped into a 20-m-long silica fibre, using a photon-echo quantum memory protocol. Despite its currently limited efficiency and storage time, our broadband light-matter interface brings fibre-based quantum networks one step closer to reality.

  14. Different operation states of soliton pulses in an erbium-doped fibre ring laser

    NASA Astrophysics Data System (ADS)

    Zhang, Shu-Min; Lü, Fu-Yun; Gong, Yan-Dong; Yang, Xiu-Feng

    2007-07-01

    We report on the experimental observation of soliton pulses in an erbium doped fibre ring laser. The passive mode-locking is achieved using the nonlinear polarization rotation technique. By adjusting the pump power and the intracavity polarization controllers, a normal soliton, a stable 8th harmonic mode-locked pulse and a noise-like pulse have been observed in our laser. The experimental results revealed that the noise-like pulse is not suitable for the optical telecommunication, and in order to obtain the stable harmonic mode-locked soliton, a strong unstable CW laser field is necessary to mediate global soliton interaction. The formation mechanism of the harmonic mode-locked pulse has also been analysed.

  15. Holmium laser transurethral incision of the prostate: Can prostate size predict the long-term outcome?

    PubMed Central

    Elkoushy, Mohamed A.; Elshal, Ahmed M.; Elhilali, Mostafa M.

    2015-01-01

    Introduction: We determine the impact of prostate size on the long-term outcome of holmium laser transurethral incision of the prostate (Ho-TUIP) for bladder outlet obstruction (BOO) secondary to benign prostate enlargement (BPE). Methods: A retrospective review of prospectively collected data was performed for patients undergoing Ho-TUIP by a single surgeon for patients presenting with lower urinary tract symptoms (LUTS) secondary to BOO. Patients were stratified into 2 groups: Group 1 included patients with prostate ≤30 cc and Group 2 included patients with prostate >30 cc. Demographic, operative and follow-up data were recorded and analyzed. In addition, intraoperative and long-term adverse events were included. Results: In total, 82 patients underwent surgery between March 1998 and March 2013, including 9 (11%) reoperated patients. Only prostate size independently predicted reoperation after Ho-TUIP (adjusted odds ratio [aOR], 95% confidence interval [CI] 7.12 [2.92–9.14], p = 0.01). The receiver operating characteristic (ROC) analysis showed an optimal cutoff value of prostate volume of 29 cc to characterize long-term reoperation after TUIP, with area under the curve (AUC) of 0.96, sensitivity of 89.7 and specificity of 88.9. Group 1 included 51 patients and Group 2 included 31 patients. The international prostate symptoms score (IPSS) and peak flow rate (Qmax) significantly improved in both groups at different follow-up points. At the 12-month follow-up, the percent change in IPSS and Qmax were comparable between both groups. However, after 12 months, the degree of improvement in all voiding parameters was significantly higher in Group 1 (p < 0.001 at all points of follow-up). After a median follow-up of 5.3 years (range: 1–13), both groups had comparable early and late adverse events with significantly higher reoperation rate in Group 2 (3.9% vs. 22.6%, p = 0.02). Overall retrograde ejaculation was detected in 25.6% of sexually active men and it was

  16. Influence of Bi on the Er luminescence in yttrium-erbium disilicate thin films

    SciTech Connect

    Scarangella, Adriana; Miritello, Maria; Priolo, Francesco

    2014-09-28

    The influence of bismuth on erbium optical properties at 1.54 μm has been investigated in yttrium-erbium disilicate thin films synthesized by magnetron co-sputtering and implanted with two Bi different doses. The Bi depth distribution and the evolution of its oxidation states after annealing treatments at 1000 °C in two atmospheres, O₂ and N₂, have been investigated. It was found that only in O₂ the Bi³⁺ valence state is prevalent, thanks to the enhanced Bi mobility in the oxidizing ambient, as demonstrated by Rutherford backscattering spectrometry. At lower Bi content, although the formation of Bi⁰ metallic nanoparticles that are deleterious non radiative channels for Er luminescence, efficient energy transfer from Bi to Er has been obtained only in O₂. It is due to the excitation of ultraviolet broad Bi₃⁺ absorption band and the energy transfer to Er ions. We have evaluated that in this case, Er effective excitation cross section increased by a factor of 5 in respect with the one for direct Er absorption at 488 nm. At higher Bi dose, this mechanism is absent, but an increased Er optical efficiency at 1.54 μm has been observed under resonant excitation. It is due to the contribution of a fraction of Er ions having an increased lifetime. This phenomenon is associated with the formation of Bi agglomerates, induced at higher Bi doses, which well isolate Er from non-radiative quenching centers. The increased decay time assures higher optical efficiency at 1.54 μm.

  17. Erbium-doped zinc-oxide waveguide amplifiers for hybrid photonic integrated circuits

    NASA Astrophysics Data System (ADS)

    O'Neal, Lawrence; Anthony, Deion; Bonner, Carl; Geddis, Demetris

    2016-02-01

    CMOS logic circuits have entered the sub-100nm regime, and research is on-going to investigate the quantum effects that are apparent at this dimension. To avoid some of the constraints imposed by fabrication, entropy, energy, and interference considerations for nano-scale devices, many have begun designing hybrid and/or photonic integrated circuits. These circuits consist of transistors, light emitters, photodetectors, and electrical and optical waveguides. As attenuation is a limiting factor in any communications system, it is advantageous to integrate a signal amplifier. There are numerous examples of electrical amplifiers, but in order to take advantage of the benefits provided by optically integrated systems, optical amplifiers are necessary. The erbium doped fiber amplifier is an example of an optical amplifier which is commercially available now, but the distance between the amplifier and the device benefitting from amplification can be decreased and provide greater functionality by providing local, on-chip amplification. Zinc oxide is an attractive material due to its electrical and optical properties. Its wide bandgap (≍3.4 eV) and high refractive index (≍2) make it an excellent choice for integrated optics systems. Moreover, erbium doped zinc oxide (Er:ZnO) is a suitable candidate for optical waveguide amplifiers because of its compatibility with semiconductor processing technology, 1.54 μm luminescence, transparency, low resistivity, and amplification characteristics. This research presents the characterization of radio frequency magnetron sputtered Er:ZnO, the design and fabrication of integrated waveguide amplifiers, and device analysis.

  18. Broadband erbium-doped fiber sources for the fiber-optic gyroscope

    SciTech Connect

    Wysocki, P.F.

    1992-01-01

    The sensitivity of early fiber-optic gyroscopes (FOG) fell short of the theoretical limit. The use of certain configurations, fiber components, and well designed optical sources can help the FOG reach this limit. Sources for the FOG must be broadband, spatially coherent and high power. They must produce a mean wavelength which is stable with respect to temperature and feedback from system components. Additionally, they must emit at long wavelengths, where silica fibers are insensitive to radiation induced losses. Two approaches to broadband, 1.55 [mu]m, erbium-doped fiber sources for the FOG are considered. The most promising approach is the superfluorescent fiber source (SFS), which utilizes amplification of spontaneous emission in a single pass or in two passes through the fiber, without a resonant cavity. Such sources have produced more than 50% conversion of pump photons near 980 nm or 1.48 [mu]m to source photons. Laser diode pumping in these pump bands is explored in detail. Depending on fiber length, pump power, pump wavelength, and SFS configuration, emission bandwidths between 8 and 27 nm are measured. The thermal coefficient of the mean wavelength of the SFS is consistently below 10 ppm/[degrees]C, and near 0 ppm/[degrees]C for certain design choices. The detrimental effects of feedback are reduced through optical isolation and the proper choice of FOG configuration. Issues such as the effect of multiple pump modes and loss mechanisms are treated by use of computer simulations. The broadband Er-doped wavelength-swept fiber laser (WSFL) is presented as an alternative to the SFS. This source utilizes an intracavity acousto-optic modulator to sweep the emission of an Er-doped laser across the gain curve of erbium. Theoretical and measured characteristics of such sources are discussed. The dynamic response of the WSFL and its coherence in an integrating system has been measured.

  19. Corneal photoablation in vivo with the erbium:YAG laser: first report

    NASA Astrophysics Data System (ADS)

    Jean, Benedikt J.; Bende, Thomas; Matallana, Michael; Kriegerowski, Martin

    1995-05-01

    As an alternative to far-UV lasers for corneal refractive surgery, the Erbium:YAG laser may be used in TEM00 mode. The resulting gaussian beam profile leads to a certain amount of myopic correction per laser pulse. Although animal data suggest that the clinical outcome should be comparable to the UV-lasers, no human data were available until now. We performed Erbium:YAG laser areal ablation in 5 blind human eyes. In TEM00 mode, the laser parameters were: effective diameter of laser spot equals 3.4 mm, fluence equals 380 mJ/cm2, pulse duration equals 250 microsecond(s) , Repetition rate equals 4 Hz, Number of applied laser pulses equals 15. Four patients with no light perception, one with intact light projection on one eye (some of them scheduled for enucleation) were treated under topical anaesthesia. Patient selection and informed consent were agreed to by the University's independent Ethics Committee. Prior to laser irradiation, corneal epithelium was removed. A postoperative silicone cast of the cornea was analyzed with a confocal laser micro-topometer for the ablation profile. The eyes were treated with antibiotic ointment until the epithelium was closed. Clinical appearance and, where possible, profilometry of the ablated area was observed. The ablation profile in cornea was gaussian shaped with a maximal depth of 30 micrometers . During laser treatment, the corneal surface becomes opaque, clearing in a matter of seconds. Epithelial healing and clinical appearance was similar to excimer laser treatment. However, during the first week, the irradiated area shows subepithelial irregularities, resembling small bubbles, disappearing thereafter.

  20. Measurements of erbium laser-ablation efficiency in hard dental tissues under different water cooling conditions.

    PubMed

    Kuščer, Lovro; Diaci, Janez

    2013-10-01

    Laser triangulation measurements of Er:YAG and Er,Cr:YSGG laser-ablated volumes in hard dental tissues are made, in order to verify the possible existence of a "hydrokinetic" effect that has been proposed as an alternative to the "subsurface water expansion" mechanism for hard-tissue laser ablation. No evidence of the hydrokinetic effect could be observed under a broad range of tested laser parameters and water cooling conditions. On the contrary, the application of water spray during laser exposure of hard dental material is observed to diminish the laser-ablation efficiency (AE) in comparison with laser exposure under the absence of water spray. Our findings are in agreement with the generally accepted principle of action for erbium laser ablation, which is based on fast subsurface expansion of laser-heated water trapped within the interstitial structure of hard dental tissues. Our measurements also show that the well-known phenomenon of ablation stalling, during a series of consecutive laser pulses, can primarily be attributed to the blocking of laser light by the loosely bound and recondensed desiccated minerals that collect on the tooth surface during and following laser ablation. In addition to the prevention of tooth bulk temperature buildup, a positive function of the water spray that is typically used with erbium dental lasers is to rehydrate these minerals, and thus sustaining the subsurface expansion ablation process. A negative side effect of using a continuous water spray is that the AE gets reduced due to the laser light being partially absorbed in the water-spray particles above the tooth and in the collected water pool on the tooth surface. Finally, no evidence of the influence of the water absorption shift on the hypothesized increase in the AE of the Er,Cr:YSGG wavelength is observed. PMID:24105399

  1. Treatment of Urethral/Bladder Neck Stricture After High-Intensity Focused Ultrasound for Prostate Cancer With Holmium: Yttrium-Aluminium-Garnet Laser

    PubMed Central

    Cho, Won Jin; Kim, Tae Heon; Lee, Hyo Serk; Chung, Jin Woo; Lee, Ha Na

    2013-01-01

    Purpose To evaluate the efficacy and safety of the Holmium: yttrium-aluminium-garnet (YAG) laser for the treatment of urethral/bladder neck strictures after high-intensity focused ultrasound for prostate cancer. Methods Between February 2007 and July 2010, Holmium: YAG laser urethrotomies were performed in eleven patients for bladder neck strictures or prostatic urethral strictures. The laser was used with a 550-µm fiber at 2 J and frequency 30 to 50 Hz. The medical records were retrospectively reviewed for medical history, perioperative and postoperative data, uroflowmetry, International Prostate Symptoms Score/quality of life, and stricture recurrence. Results At a median follow-up of 12.0 months (range, 4 to 35 months), the mean postoperative maximal flow rate and residual volume were improved significantly (P<0.05). The mean postoperative total, voiding and quality of life of international prostate symptom score were improved significantly (P<0.05). Of the 11 patients, 7 patients required one treatment, 4 patients two treatment, and 1 patients three treatment. 2 patients who had a documented urinary incontinence prior to the laser treatment subsequently required artificial urinary sphincter implantation and reported satisfaction without developing any recurrent strictures or artificial urinary sphincter erosion. All patients exhibited well-healed strictures and could void without difficulty. Conclusions Holmium: YAG laser therapy represents a safe, effective and minimally invasive treatment for urethral/bladder neck strictures occurring secondary to high-intensity focused ultrasound for prostate cancer. PMID:23610708

  2. Sialoendoscopy with and without holmium:YAG laser-assisted lithotripsy in the management of obstructive sialadenitis of major salivary glands.

    PubMed

    Sionis, S; Caria, R A; Trucas, M; Brennan, P A; Puxeddu, R

    2014-01-01

    Obstructive sialadenitis is a major cause of dysfunction of the salivary glands, and increasingly sialoendoscopy is used in both diagnosis and treatment. At present the limit of the endoscopic approach is the size of the stone as only stones of less than 4mm can be removed. Endoscopic laser lithotripsy has the potential to treat many stones larger than this with minimal complications and preservation of a functional salivary gland. The holmium:YAG laser has been widely and safely used in urology, and its use has been recently proposed in salivary lithotripsy for the removal of bigger stones. We describe our experience with sialoendoscopy for stones in the parotid and submandibular glands and assess the feasibility and the efficacy of holmium:YAG laser lithotripsy. We have used the procedure 50 times for 43 patients with obstructive sialadenitis; 31 patients had sialolithiasis, 15 of whom (48%) had stones with diameters between 4 and 15mm (mean 7). Total extraction after fragmentation was possible in 14 of the 15 patients without complications. Intraductal holmium:YAG laser lithotripsy is effective and safe, and allows the treatment of large stones in Stensen's and Wharton's ducts. PMID:24280118

  3. High Temperature Superconductivity in Praseodymium Doped (0%, 2%, 4%) in Melt-Textured Y(1-x)Pr(x)Ba2Cu3O(7-delta) Systems

    NASA Technical Reports Server (NTRS)

    James, Claudell

    1995-01-01

    A study of the magnetic and structural properties of the alloy Y(1-x)Pr(x)Ba2Cu3O(7-delta) of 0%, 2%, and 4% doping of praseodymium is presented. The resulting oxides of the alloy series are a high-temperature superconductor Y-Ba-Cu-O, which has an orthorhombic superconducting crystal-lattice. Magnetic relaxation studies have been performed on the Y-Pr-Ba-CuO bulk samples for field orientation parallel to the c-axis, using a vibrating sample magnetometer. Relaxation was measured at several temperatures to obtain the irreversible magnetization curves used for the Bean model. Magnetization current densities were derived from the relaxation data. Field and temperature dependence of the logarithmic flux-creep relaxation was measured in critical state. The data indicates that the effective activation energy U(eff) increases with increasing T between 77 K and 86 K. Also, the data shows that U(eff)(T) and superconducting transition temperature, Tc, decreased as the lattice parameters increased with increasing Pr ion concentration, x, for the corresponding Y(1-x)Pr(x)Ba(x)Cu3O(7-delta) oxides. One contribution to Tc decrease in this sampling is suspected to be due to the larger ionic radius of the Pr(3+) ion. The upper critical field (H(sub c2)) was measured in the presence of magnetic field parallel to the c axis. A linear temperature dependence with H(sub c2) was obtained.

  4. Core-pumped gain-guided index-antiguided continuous wave lasing in dispersion-engineered erbium-doped fiber.

    PubMed

    Chen, Nan-Kuang; Jian, Lian-Jiun

    2012-08-01

    We demonstrate core-pumped gain-guided index-antiguided fiber lasers using a 22 cm long dispersion-engineered erbium-doped fiber. The erbium-doped fiber is dispersion-engineered using optical liquid to replace the most part of silica cladding so that the index of core turns out to be higher (lower) than that of new cladding at pump (lasing) wavelength, respectively. The pump light is confined to propagate in core based on an index-guiding mechanism to efficiently excite the gain medium running through the fiber whereas the cw lasing is constructed in a long, small-core waveguide under a gain-guided, index-antiguided situation. PMID:22859084

  5. Ultrawide broadband photonic source based on a new design of mode-locked erbium-doped fibre laser

    NASA Astrophysics Data System (ADS)

    Jarabo, S.; Salgado-Remacha, F. J.

    2015-09-01

    Pulses with a spectral width of 134 nm at  -6 dBm nm-1 and 223 nm at  -20 dBm nm-1, covering L-band and U-band and longer wavelengths (even beyond 1700 nm), are achieved by means of a new design of passive mode-locked erbium-doped fibre laser. This source includes a C/L-band filter inside a ring cavity with an L-band erbium-doped fibre amplifier as active medium and its output pulses are amplified by means of a second L-band amplifier. It is demonstrated that output spectra are clearly broadened due to the presence of the C/L band filter.

  6. Reduced erbium-doped ceria nanoparticles: one nano-host applicable for simultaneous optical down- and up-conversions

    PubMed Central

    2014-01-01

    This paper introduces a new synthesis procedure to form erbium-doped ceria nanoparticles (EDC NPs) that can act as an optical medium for both up-conversion and down-conversion in the same time. This synthesis process results qualitatively in a high concentration of Ce3+ ions required to obtain high fluorescence efficiency in the down-conversion process. Simultaneously, the synthesized nanoparticles contain the molecular energy levels of erbium that are required for up-conversion. Therefore, the synthesized EDC NPs can emit visible light when excited with either UV or IR photons. This opens new opportunities for applications where emission of light via both up- and down-conversions from a single nanomaterial is desired such as solar cells and bio-imaging. PMID:24940173

  7. Efficient and long-lived Zeeman-sublevel atomic population storage in an erbium-doped glass fiber

    NASA Astrophysics Data System (ADS)

    Saglamyurek, Erhan; Lutz, Thomas; Veissier, Lucile; Hedges, Morgan P.; Thiel, Charles W.; Cone, Rufus L.; Tittel, Wolfgang

    2015-12-01

    Long-lived population storage in optically pumped levels of rare-earth ions doped into solids, referred to as persistent spectral hole burning, is of significant fundamental and technological interest. However, the demonstration of deep and persistent holes in rare-earth ion doped amorphous hosts, e.g., glasses, has remained an open challenge for many decades—a fact that motivates our work towards a better understanding of the interaction between impurities and vibrational modes in glasses. Here we report the observation and detailed characterization of such holes in an erbium-doped silica glass fiber cooled to below 1 K. We demonstrate population storage in electronic Zeeman sublevels of the erbium ground state with lifetimes up to 30 seconds and 80% spin polarization. In addition to its fundamental aspect, our investigation reveals a potential technological application of rare-earth ion doped amorphous materials, including at telecommunication wavelength.

  8. Seven-core erbium-doped double-clad fiber amplifier pumped simultaneously by side-coupled multimode fiber.

    PubMed

    Abedin, Kazi S; Fini, John M; Thierry, Taunay F; Zhu, Benyuan; Yan, Man F; Bansal, Lalit; Dimarcello, Frank V; Monberg, Eric M; DiGiovanni, David J

    2014-02-15

    We demonstrate a seven-core erbium-doped fiber amplifier in which all the cores were pumped simultaneously by a side-coupled tapered multimode fiber. The amplifier has multicore (MC) MC inputs and MC outputs, which can be readily spliced to MC transmission fiber for amplifying space division multiplexed signals. Gain over 25 dB was obtained in each of the cores over a 40-nm bandwidth covering the C-band. PMID:24562260

  9. On the possibility of increasing the pulse energy of a passively Q-switched erbium glass minilaser

    SciTech Connect

    Izyneev, A A; Sadovskii, Pavel I; Sadovskii, S P

    2010-08-03

    A simple method to increase the output energy of a passively Q-switched erbium glass laser is proposed. Using the amplitude modulation of losses at the active element face, the fundamental mode was reliably suppressed and the laser operated in a selected higher-order mode. The output energy was experimentally increased by a factor of 2.1, and the range of allowable pump energy instability was extended threefold. (lasers)

  10. Self-mode-locked all-fibre erbium laser with a low repetition rate and high pulse energy

    SciTech Connect

    Denisov, Vladimir I; Nyushkov, B N; Pivtsov, V S

    2010-01-31

    Self-starting mode locking is demonstrated for the first time in an all-fibre erbium laser with a cavity length above 1 km and high positive (normal) intracavity dispersion. The unconventional cavity design, with polarisation instability compensation, ensures stable operation and good frequency stability. The laser generates pulses with a record low repetition rate (82.4 kHz) and record high energy (564.3 nJ). (lasers)

  11. Effects of non-ablative fractional erbium glass laser treatment on gene regulation in human three-dimensional skin models.

    PubMed

    Amann, Philipp M; Marquardt, Yvonne; Steiner, Timm; Hölzle, Frank; Skazik-Voogt, Claudia; Heise, Ruth; Baron, Jens M

    2016-04-01

    Clinical experiences with non-ablative fractional erbium glass laser therapy have demonstrated promising results for dermal remodelling and for the indications of striae, surgical scars and acne scars. So far, molecular effects on human skin following treatment with these laser systems have not been elucidated. Our aim was to investigate laser-induced effects on skin morphology and to analyse molecular effects on gene regulation. Therefore, human three-dimensional (3D) organotypic skin models were irradiated with non-ablative fractional erbium glass laser systems enabling qRT-PCR, microarray and histological studies at same and different time points. A decreased mRNA expression of matrix metalloproteinases (MMPs) 3 and 9 was observed 3 days after treatment. MMP3 also remained downregulated on protein level, whereas the expression of other MMPs like MMP9 was recovered or even upregulated 5 days after irradiation. Inflammatory gene regulatory responses measured by the expression of chemokine (C-X-C motif) ligands (CXCL1, 2, 5, 6) and interleukin expression (IL8) were predominantly reduced. Epidermal differentiation markers such as loricrin, filaggrin-1 and filaggrin-2 were upregulated by both tested laser optics, indicating a potential epidermal involvement. These effects were also shown on protein level in the immunofluorescence analysis. This novel standardised laser-treated human 3D skin model proves useful for monitoring time-dependent ex vivo effects of various laser systems on gene expression and human skin morphology. Our study reveals erbium glass laser-induced regulations of MMP and interleukin expression. We speculate that these alterations on gene expression level could play a role for dermal remodelling, anti-inflammatory effects and increased epidermal differentiation. Our finding may have implications for further understanding of the molecular mechanism of erbium glass laser-induced effects on human skin. PMID:26796701

  12. Resonantly pumped, erbium-doped, GSGG, 2.8 micron, solid state laser with energy recycling and high slope efficiency

    NASA Astrophysics Data System (ADS)

    Esterowitz, Leon; Stoneman, Robert C.

    1993-04-01

    This invention is a laser system and method for producing a laser emission at a wavelength of substantially 2.8 microns and having a quantum efficiency of at least unity and a slope efficiency of about 36%. In a preferred embodiment of the invention, the laser system comprises a laser cavity defined by first and second reflective elements with one of the reflective elements operating as an output coupler; a crystal disposed in the laser cavity and having a GSGG host material doped with a preselected percent concentration of erbium, the GSGG host material and preselected percent concentration of erbium being selected so as to provide a quantum efficiency of at least unity by the 4I13/2 + 4I13/2 right arrow 4I9/2 + 4I15/2 upconversion process and a slope efficiency of about 36% when the crystal is resonantly pumped; and a resonant pump laser for directly pumping the 4I11/2 upper laser state of the erbium with a pump beam to cause the crystal to produce a laser emission corresponding to the 4I11/2 right arrow 4I13/2 laser transition having a wavelength of substantially 2.8 microns.

  13. Resonantly pumped, erbium-doped, GSGG, 2.8 micron, solid state laser with energy recycling and high slope efficiency

    NASA Astrophysics Data System (ADS)

    Esterowitz, Leon; Stoneman, Robert

    1992-05-01

    A laser system and a method for producing a laser emission at a wavelength of approximately 2.8 microns are presented. The system and method have a quantum efficiency of at least unity and a slope efficiency of about 36 percent. The laser system is comprised of the following: a laser cavity defined by first and second reflective elements with one of the reflective elements operating as an output coupler; a crystal disposed in the laser cavity and having a GSGG host material doped with a preselected percent concentration of erbium, the GSGG host material and preselected percent concentration of erbium being selected so as to provide a quantum efficiency of at least unity by the (sup 4)I(sub 13/2) + (sup 4)I(sub 13/2) yields (sup 4)I(sub9/2) + (sup 4)I(sub 15/2) upconversion process and a slope efficiency of about 36 percent when the crystal is resonantly pumped; and a resonant pump laser for directly pumping the (sup 4)I(sub 11/2) upper laser state of the erbium with a pump beam to cause the crystal to produce a laser emission corresponding to the (sup 4)I(sub 11/2) yields (sup 4)I(sub 13/2) laser transition having a wavelength of substantially 2.8 microns.

  14. Detecting Thermal Barrier Coating Delamination Using Visible and Near-Infrared Luminescence from Erbium-Doped Sublayers

    NASA Technical Reports Server (NTRS)

    Eldridge, J. I.; Bencic, T. J.; Martin, R. E.; Singh, J.; Wolfe, D. E.

    2007-01-01

    Nondestructive diagnostic tools are needed to monitor early stages of delamination progression in thermal barrier coatings (TBCs) because the risk of delamination induced coating failure will compromise engine performance and safety. Previous work has demonstrated that for TBCs composed of yttria-stabilized zirconia (YSZ), luminescence from a buried europium-doped sublayer can be utilized to identify the location of TBC delamination from the substantially higher luminescence intensity observed from the delaminated regions of the TBC. Luminescence measurements from buried europium-doped layers depend on sufficient transmittance of the 532 nm excitation and 606 nm emission wavelengths through the attenuating undoped YSZ overlayer to produce easily detected luminescence. In the present work, improved delamination indication is demonstrated using erbium-doped YSZ sublayers. For visible-wavelength luminescence, the erbium-doped sublayer offers the advantage of a very strong excitation peak at 517 nm that can be conveniently excited a 514 nm Ar ion laser. More importantly, the erbium-doped sublayer also produces near-infrared luminescence at 1550 nm that is effectively excited by a 980 nm laser diode. Both the 980 nm excitation and the 1550 nm emission are transmitted through the TBC with much less attenuation than visible wavelengths and therefore show great promise for delamination monitoring through thicker or more highly scattering TBCs. The application of this approach for both electron beam physical vapor deposited (EB-PVD) and plasma-sprayed TBCs is discussed.

  15. Experimental investigations of the use of an erbium:YAG laser on temporomandibular joint (TMJ) structures: first experimental results

    NASA Astrophysics Data System (ADS)

    Nuebler-Moritz, Michael; Niederdellmann, Herbert; Hering, Peter; Deuerling, Christian; Dammer, Ralf; Behr, M.

    1995-04-01

    The following paper introduces the results of an interdisciplinary research project. With the aid of photomacroscopic examination, light and scanning electron microscope investigations, changes to temporomandibular joint structures were detected in vitro after irradiation with an Erbium:YAG laser system. The solid-state Erbium:YAG laser, operating at a wavelength of 2.94 micrometers was used in the normal- spiking mode. The free-running laser beam was focussed onto freshly excised porcine tissue samples using a 108-mm sapphire lens. In this study the output was generally pulsed at a repetition rate of 4 Hz, with a pulse duration varying from 120 microsecond(s) to 500 microsecond(s) . Between 50 mJ and 500 mJ per pulse were applied to create pinpoint lesions. The optimum average energy density and pulse duration of the Erbium:YAG laser radiation for the purpose of TMJ-surgery (as far as it concerns meniscus and articulating facets) - which means efficient etch rate and minimal adjacent injury - seems to be about 24-42 J/cm2 and 120 microsecond(s) -240 microsecond(s) , respectively.

  16. Photocatalytic activity of erbium-doped TiO{sub 2} nanoparticles immobilized in macro-porous silica films

    SciTech Connect

    Castaneda-Contreras, J.; Maranon-Ruiz, V.F.; Chiu-Zarate, R.; Perez-Ladron de Guevara, H.; Rodriguez, R.; Michel-Uribe, C.

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Erbium-doped TiO{sub 2} nanoparticles were immobilized on macro-porous silica films. Black-Right-Pointing-Pointer The films were obtained by a phase separation process. Black-Right-Pointing-Pointer The samples exhibited photo-catalytic activity under visible light. Black-Right-Pointing-Pointer The sensitization of TiO{sub 2} was attributed to a red shift in the TiO{sub 2} band-gap. -- Abstract: A macro-porous silica film served as mechanical support to immobilize TiO{sub 2} nanoparticles, which were doped with erbium. The films and the nanoparticles were prepared by sol-gel route. The nanoparticles exhibited photocatalytic activity under visible light. We obtained a degradation rate of methylene blue that followed first order kinetics. The sensitization of the nanoparticles to visible light was attributed to a red shift in the band-gap of the TiO{sub 2} due to the addition of erbium ions.

  17. Wideband and flat-gain amplifier based on high concentration erbium-doped fibres in parallel double-pass configuration

    SciTech Connect

    Hamida, B A; Cheng, X S; Harun, S W; Naji, A W; Arof, H; Al-Khateeb, W; Khan, S; Ahmad, H

    2012-03-31

    A wideband and flat gain erbium-doped fibre amplifier (EDFA) is demonstrated using a hybrid gain medium of a zirconiabased erbium-doped fibre (Zr-EDF) and a high concentration erbium-doped fibre (EDF). The amplifier has two stages comprising a 2-m-long ZEDF and 9-m-long EDF optimised for C- and L-band operations, respectively, in a double-pass parallel configuration. A chirp fibre Bragg grating (CFBG) is used in both stages to ensure double propagation of the signal and thus to increase the attainable gain in both C- and L-band regions. At an input signal power of 0 dBm, a flat gain of 15 dB is achieved with a gain variation of less than 0.5 dB within a wide wavelength range from 1530 to 1605 nm. The corresponding noise figure varies from 6.2 to 10.8 dB within this wavelength region.

  18. Holmium-166 radioembolization for the treatment of patients with liver metastases: design of the phase I HEPAR trial

    PubMed Central

    2010-01-01

    Background Intra-arterial radioembolization with yttrium-90 microspheres ( 90Y-RE) is an increasingly used therapy for patients with unresectable liver malignancies. Over the last decade, radioactive holmium-166 poly(L-lactic acid) microspheres ( 166Ho-PLLA-MS) have been developed as a possible alternative to 90Y-RE. Next to high-energy beta-radiation, 166Ho also emits gamma-radiation, which allows for imaging by gamma scintigraphy. In addition, Ho is a highly paramagnetic element and can therefore be visualized by MRI. These imaging modalities are useful for assessment of the biodistribution, and allow dosimetry through quantitative analysis of the scintigraphic and MR images. Previous studies have demonstrated the safety of 166Ho-PLLA-MS radioembolization ( 166Ho-RE) in animals. The aim of this phase I trial is to assess the safety and toxicity profile of 166Ho-RE in patients with liver metastases. Methods The HEPAR study (Holmium Embolization Particles for Arterial Radiotherapy) is a non-randomized, open label, safety study. We aim to include 15 to 24 patients with liver metastases of any origin, who have chemotherapy-refractory disease and who are not amenable to surgical resection. Prior to treatment, in addition to the standard technetium-99m labelled macroaggregated albumin ( 99mTc-MAA) dose, a low radioactive safety dose of 60-mg 166Ho-PLLA-MS will be administered. Patients are treated in 4 cohorts of 3-6 patients, according to a standard dose escalation protocol (20 Gy, 40 Gy, 60 Gy, and 80 Gy, respectively). The primary objective will be to establish the maximum tolerated radiation dose of 166Ho-PLLA-MS. Secondary objectives are to assess tumour response, biodistribution, performance status, quality of life, and to compare the 166Ho-PLLA-MS safety dose and the 99mTc-MAA dose distributions with respect to the ability to accurately predict microsphere distribution. Discussion This will be the first clinical study on 166Ho-RE. Based on preclinical studies

  19. Spectroscopic characteristics of praseodymium-doped cubic double sodium-yttrium fluoride crystals Na0.4Y0.6F2.2:Pr3+. Intensities of optical transitions and luminescence kinetics

    NASA Astrophysics Data System (ADS)

    Tkachuk, A. M.; Ivanova, S. E.; Mirzaeva, A. A.; Joubert, M.-F.; Guyot, Y.

    2014-03-01

    Using the Bridgman-Stockbarger technique, we have grown a series of cubic crystals Na0.4Y0.6F2.2:Pr3+ (NYF:Pr3+) with a content of praseodymium in the range of 0.04-9 at %. We have determined the composition of crystals, evaluated their optical quality, and found the incorporation coefficient of Pr3+ ions into the Na0.4Y0.6F2.2 matrix ( K Pr ˜ 0.9). We have examined optical spectra of NaYF:Pr3+ crystals at room and low (7 K) temperatures in the range of 200-2500 nm. The low-temperature absorption spectra of NYF:Pr3+ crystals have been shown to consist of broad weakly structured bands. Based on the analysis of low-temperature absorption spectra, the structure of the Stark splitting of praseodymium levels has been represented in terms of a model of "quasi-centers," which are characterized by an inhomogeneous broadening of Stark components. From experimental absorption cross-section spectra at T = 300 K, we have calculated oscillator strengths for transitions from the ground state 3 H 4 to excited multiplets 3 H 5, 3 H 6, 3 F j ( j = 2, 3, 4), 1 G 4, 1 D 2, and (3 P j ,1 I 6) ( j = 0, 1, 2). Using the Judd-Ofelt method, we have determined intensity parameters Ω t and found that Ω2 = 0, Ω4 = 4.4 × 10-20, and Ω6 = 2.28 × 10-20 cm2. With these values, we have calculated the probabilities of radiative transitions, the branching coefficients, and the lifetimes of the radiative levels 1 D 2 and 3 P 0. The probabilities of multiphonon nonradiative transitions in NYF:Pr3+ crystals have been estimated. Using the method of kinetic spectroscopy with selective excitation, we have investigated the luminescence decay kinetics of praseodymium from the 3 P 0 and 1 D 2 levels upon their selective resonant excitation by nanosecond laser pulses. The inference has been made that Na0.4Y0.6F2.2:Pr3+ crystals are processable; admit doping by praseodymium in high concentrations; and, with respect to all their radiative characteristics, can be potentially considered as active media for

  20. Erbium And The r-Process In The Sun And Metal-poor Stars

    NASA Astrophysics Data System (ADS)

    Lawler, James; Sneden, C.; Cowan, J. J.

    2007-12-01

    Recent laboratory radiative lifetimes accurate to 5% for 8 even-parity and 72 odd-parity levels of Er II (Stockett et al. 2007, J. Phys. B, in press) were combined with emission branching fractions from Fourier transform spectra to determine accurate absolute transition probabilities for 418 lines of Er II. The lines span the UV to IR wavelength range from 289.2 to 1984.1 nm. Our gf-values have been applied to refine the solar photospheric erbium abundance and to determine erbium abundances in 4 metal-poor giant stars with enhanced r-process abundances (those with [Fe/H] < -2, [Eu/Fe] > +0.5). For the Sun we derive log ɛ(Er) = 0.96 ± 0.02 (σ = 0.06 from 8 lines). This value is in excellent agreement with Lodders' (2003, ApJ, 591, 1220) recommended meteoritic abundance: log ɛ(Er) = 0.95 ± 0.03. Combining the new photospheric Er abundance with our earlier study of Eu (log ɛ(Er) = 0.52 ± 0.01; Lawler et al. 2001, ApJ, 563, 1075) yields log ɛ(Er/Eu) = 0.43 for the Sun. The origin of both Er and Eu are attributed predominantly to production in rapid neutron-capture synthesis (the r-process) in solar-system material, 83% and 97% respectively (Simmerer et al. 2004, ApJ, 617, 1091). We therefore applied the new transition data to the spectra of very metal-poor, r-process rich stars CS 22892-052, BD+17 3248, HD 115444, and HD 221170. Between 14 and 21 Er II features were usable in our abundance analyses in these stars. We derived = 0.43 for the four stars, obviously in excellent agreements with the solar value. This work has been supported by the National Science Foundations through grants AST-0506324 to JEL, AST-0607708 to CS, and AST-0707447 to JJC.

  1. Simplified gain calculation in erbium-doped LiNbO 3 waveguides

    NASA Astrophysics Data System (ADS)

    Kapoor, Amita; Jain, Geetika; Sharma, Enakshi K.

    2007-02-01

    The combination of excellent electro-optical, acousto-optical and non-linear optical properties makes lithium niobate (LiNbO 3) an attractive host material for integrated optical components such as electro-optical modulators, acousto-optically tunable wavelength filters and Bragg gratings. In the last few years Erbium doped LiNbO 3 waveguide optical amplifiers (EDWA's) have attracted increasing interest. The combination of the amplifying properties of erbium with the excellent acousto-optical and electro-optical properties of the waveguide substrate LiNbO 3 allows the development of a whole class of new waveguide devices of higher functionality. The optical gain achievable in Ti:Er:LiNbO 3 waveguides by optical pumping could compensate or even over compensate these scattering, absorption and insertion losses leading to "zero loss" devices with net optical gain. The different types of lasers and amplifiers can be combined with other active and passive devices on the same substrate to form integrated optical circuits (IOC's) for a variety of applications in optical communications, sensing, signal processing and measurement techniques. The analysis of Er-doped diffused channel waveguides is, hence, required for design of amplifying integrated optical circuits in order to optimize the performance of these gain devices. The coupled differential equations, which govern the evolution of, pump power (1484nm), signal power (1485 to 1600nm) and amplified spontaneous emission, involve integrals which depend explicitly on the modal fields at the pump and signal wavelength in the diffused channel waveguide. In general, it is not possible to obtain analytical forms for the modal fields and propagation constant, hence, to obtain them various approximate or numerical methods (BPM, finite difference or finite element) are used. In this paper the modal field profiles obtained by the variational analysis are further approximated to an appropriately chosen Gaussian function, which

  2. Strictions and new stripe phases of epitaxial erbium (0001) on sapphire (1120)

    NASA Astrophysics Data System (ADS)

    Durfee, Curtis Scott

    Erbium thin films provide a valuable model system with which to explore two phenomena that have made the magnetic phase diagram of thin films hard to predict. These are the elastic energy of epitaxial misfit and the magnetostatic energy of the equilibrium configuration. In both cases, Er is particularly well suited to the fundamental investigation of equilibrium magnetic phases. First, Er exhibits large strictions of ˜0.3% at its bulk transition from the antiferromagnetic (AF) to the ferromagnetic (FM) phase. The elastic free energy created by the substrate-induced strains is almost sufficient to suppress ferromagnetism of the film entirely. Second, erbium can be grown epitaxially on its basal plane. In this orientation, the magnetization is aligned perpendicular to the film, and greatly enhances the magnetostatic energy. This is also sufficiently large to overcome the free energy difference between the bulk FM and AF phases. In this thesis, thin epitaxial films of Er were synthesized and their magnetic phase diagrams explored by magnetic and x-ray measurements. The research reveals new fundamental behavior of magnetic thin films, including the discovery of two new magnetic stripe phases. The newly observed stripe phases separate the AF and FM phases in the phase diagrams of the films and significantly reduce the large demagnetizing energy from that of the uniform FM film. The low-temperature stripe phase is comprised of periodic FM domains that alternate in direction along the hcp c axis. The high-temperature stripe phase is formed by alternating AF and FM domains. These domains adjust their relative widths in an increasing field in such a way that the net internal field is nearly zero throughout the magnetization process. Thus, the demagnetizing energy nearly vanishes. The stripe phases then mediate the AF to FM transition that occurs directly in the bulk. The experimentally-determined phase diagrams were predicted from the Gibbs free energies of the phases. The

  3. Study of the line intensity in the optical and magnetooptical spectra in holmium-containing paramagnetic garnets

    NASA Astrophysics Data System (ADS)

    Valiev, Uygun V.; Gruber, John B.; Burdick, Gary W.; Pelenovich, Vasiliy O.; Fu, Dejun; Dzhuraev, Davron R.

    2016-01-01

    Studies of line intensity in the optical and magneto-optical spectra in the holmium-containing paramagnetic garnet Ho3+:YAG were carried out within the visible spectrum at T = 85 K. Detailed investigation of the magnetic circularly polarized luminescence spectra at 85 and 300 K on 5S2 → 5I8 emission transition in Ho3+:YAG was carried out. A quasi-doublet state in the energy spectrum of the Ho3+ ions was observed, characterized by a significant magneto-optical activity, which is caused by a large Zeeman splitting of the quasi-doublet. The measurement of the magnetic circular polarized luminescence spectrum carried out within one of the emission lines of the luminescence band 5S2 → 5I8 in Ho3+:YAG at 85 K shows significant magneto-optical effects of the intensity change of the emitted light, compared to that measured for the other emission lines in the same luminescent band.

  4. Holmium:YAG laser lithotripsy for the management of urolithiasis in small ruminants and pot-bellied pigs

    NASA Astrophysics Data System (ADS)

    Halland, Spring K.; House, John K.; George, Lisle

    2001-05-01

    Obstructive urolithiasis is a common problem in small ruminants and pot-bellied pigs. The most common site of urinary tract obstruction in these species is the urethra. Surgical procedures developed to relieve obstructions, in our experience have been effective in approximately 75% of cases. Urethral stricture is a common complication if the mucosa of the urethra is disrupted. The objective of this project was to evaluate endoscopy guided laser lithotripsy as a therapeutic modality to relieve urethral obstructions in small ruminants and pot-bellied pigs. The study population consisted of patients presented to the Veterinary Medical Teaching Hospital at the University of California Davis with obstructive urolithiasis. Lithotripsy was performed using a Holmium:YAG laser via a 200-micron low water quartz fiber passed through a flexible mini-endoscope. Two types of urinary calculi were managed with this technique, calcium carbonate and calcium hydroxyphosphate. Laser lithotripsy was effective at relieving obstructions caused by both types of calculi when conventional methods had failed. Laser lithotripsy performed via urethral endoscopy is a safe and effective therapeutic modality for management of obstructive urolithiasis in small ruminants and pot-bellied pigs and reduces the risk of post procedural urethral stricture.

  5. Predictive risk factors of postoperative urinary incontinence following holmium laser enucleation of the prostate during the initial learning period

    PubMed Central

    Kobayashi, Shuichiro; Yano, Masataka; Nakayama, Takayuki; Kitahara, Satoshi

    2016-01-01

    ABSTRACT Purpose: To determine the predictive factors for postoperative urinary incontinence (UI) following holmium laser enucleation of the prostate (HoLEP) during the initial learning period. Patients and Methods: We evaluated 127 patients with benign prostatic hyperplasia who underwent HoLEP between January 2011 and December 2013. We recorded clinical variables, including blood loss, serum prostate-specific antigen levels, and the presence or absence of UI. Blood loss was estimated as a decline in postoperative hemoglobin levels. The predictive factors for postoperative UI were determined using a multivariable logistic regression analysis. Results: Postoperative UI occurred in 31 patients (24.4%), but it cured in 29 patients (93.5%) after a mean duration of 12 weeks. Enucleation time >100 min (p=0.043) and blood loss >2.5g/dL (p=0.032) were identified as significant and independent risk factors for postoperative UI. Conclusions: Longer enucleation time and increased blood loss were independent predictors of postoperative UI in patients who underwent HoLEP during the initial learning period. Surgeons in training should take care to perform speedy enucleation maneuver with hemostasis. PMID:27564285

  6. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate.

    PubMed

    Saito, Keisuke; Hisasue, Shin-ichi; Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53-88) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 6-35) to 3 (0-22) (p < 0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (2-20) to 3 (1-8) (p < 0.001). Median bladder blood flow increased at the trigone from 9.57 ± 0.83 ml/sec to 17.60 ± 1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  7. The Impact of Increased Bladder Blood Flow on Storage Symptoms after Holmium Laser Enucleation of the Prostate

    PubMed Central

    Ide, Hisamitsu; Aoki, Hiroaki; Muto, Satoru; Yamaguchi, Raizo; Tsujimura, Akira; Horie, Shigeo

    2015-01-01

    In order to investigate how holmium laser enucleation of the prostate (HoLEP) improves urinary storage symptoms, we assessed blood flow in the urinary bladder mucosa of patients with benign prostatic hyperplasia (BPH) before and after laser surgery. Seventy-four consecutive patients with BPH (median age 69 years, range; 53–88) underwent HoLEP at our institution and are included in this study. We prospectively assessed the International Prostate Symptom Score (IPSS), IPSS-QOL Score, the Overactive Bladder Symptom Score (OABSS), uroflowmetry, and blood flow in the urinary bladder, before and after surgery. Blood flow in the bladder mucosa was measured using the OMEGA FLOW (OMEGAWAVE, Tokyo, Japan) laser Doppler flowmeter. The median volume of the enucleated adenomas was 45.0 g (range: 25.0 to 83.2). The median IPSS improved significantly from 20 (range: 6–35) to 3 (0–22) (p<0.001; Wilcoxon signed-rank test), as did the storage symptoms score, which decreased from 13 (2–20) to 3 (1–8) (p<0.001). Median bladder blood flow increased at the trigone from 9.57±0.83 ml/sec to 17.60±1.08 ml/sec. Multiple regression analysis for the improved storage symptom score eliminated all explanatory variables except increased bladder perfusion. The data suggest that HoLEP improves blood flow in the bladder mucosa, which independently leads to the improvement of storage symptoms. PMID:26090819

  8. Comparison of the effects of lanthanum, cerium and praseodymium on rumen fermentation, nutrient digestion and plasma biochemical parameters in beef cattle.

    PubMed

    Lin, Shixin; Wei, Chen; Zhao, Guangyong; Zhang, Tingting; Yang, Kai

    2015-01-01

    The objectives of the trial were to compare the effects of supplementing rare earth elements (REE) lanthanum (La), cerium (Ce) and praseodymium (Pr) on rumen fermentation, nutrient digestion, methane (CH4) production, nitrogen (N) balance and plasma biochemical parameters in beef cattle. Four Simmental male cattle, aged 12 months, with initial average liveweight of 333 ± 9 kg and fitted with rumen cannulas, were fed with a basal ration composed of concentrate mixture and maize silage. Animals received a basal ration without adding REE (Control) or three treatments, i.e. supplementing LaCl3, CeCl3 or PrCl3 at 204 mg/kg DM to the basal ration, respectively, which were allocated in a 4 × 4 Latin square design. Each experimental period lasted 15 d, consisting of 12 d for pre-treatment and three subsequent days for sampling. Results showed that all tested levels of REE tended to increase neutral detergent fibre digestibility (p = 0.064) and tended to decrease rumen CH4 production (p = 0.056). Supplementing LaCl3 and CeCl3 decreased total N excretion and urinary N excretion, increased N retention (p < 0.05), tended to increase total urinary purine derivatives (PD) (p = 0.053) and microbial N flow (p = 0.095), whereas supplementing PrCl3 did not affect N retention, urinary PD and microbial N flow. No differences were found in the effects of nutrient digestibility, CH4 production and plasma biochemical parameters among LaCl3, CeCl3 and PrCl3. Further trials using graded levels of LaCl3, CeCl3 and PrCl3 in a wide range are needed to obtain more pronounced results for comparing effects of La, Ce and Pr on rumen fermentation and nutrient digestion in beef cattle. PMID:25575216

  9. High-energy, in-band pumped erbium doped fiber amplifiers.

    PubMed

    Lim, Ee-Leong; Shaif-ul Alam; Richardson, David J

    2012-08-13

    We have demonstrated and compared high-energy, in-band pumped erbium doped fiber amplifiers operating at 1562.5 nm under both a core pumping scheme (CRS) and a cladding pumping scheme (CLS). The CRS/CLS sources generated smooth, single-peak pulses with maximum pulse energies of ~1.53/1.50 mJ, and corresponding pulse widths of ~176/182 ns respectively, with an M2 of ~1.6 in both cases. However, the conversion efficiency for the CLS was >1.5 times higher than the equivalent CRS variant operating at the same pulse energy due to the lower pump intensity in the CLS that mitigates the detrimental effects of ion concentration quenching. With a longer fiber length in a CLS implementation a pulse energy of ~2.6 mJ is demonstrated with a corresponding M2 of ~4.2. Using numerical simulations we explain that the saturation of pulse energy observed in our experiments is due to saturation of the pump absorption. PMID:23038520

  10. Decontamination of deep dentin by means of erbium, chromium:yttrium-scandium-gallium-garnet laser irradiation.

    PubMed

    Franzen, René; Esteves-Oliveira, Marcella; Meister, Jörg; Wallerang, Anja; Vanweersch, Leon; Lampert, Friedrich; Gutknecht, Norbert

    2009-01-01

    The aim of this in vitro study was to evaluate the depth of effectiveness of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on microorganism reduction. From human roots, dentin slices of 100 microm to 1,000 microm thickness were prepared. These specimens were sterilized and then inoculated with 1 microl of Enterococcus faecalis suspension. The backs of the specimens were then irradiated with Er,Cr:YSGG radiation at a pulse energy of 3.13 mJ, delivered at an incidence angle of 5 degrees to the dentin slice surface. A control group was left without irradiation. The remaining bacteria were collected in 1 ml sterilized NaCl solution, serially diluted and seeded in Columbia-Agar plates. Despite the low pulse energy of 3.13 mJ, the Er,Cr:YSGG laser irradiation resulted in significant bacterial reduction up to a dentin thickness of 500 microm (P < 0.05). Scanning electron microscopy (SEM) micrographs of the contaminated and irradiated surfaces showed the absence of a smear layer and opened dentinal tubules. PMID:18027063

  11. Isolator-free switchable uni- and bidirectional hybrid mode-locked erbium-doped fiber laser.

    PubMed

    Chernysheva, Maria; Araimi, Mohammed Al; Kbashi, Hani; Arif, Raz; Sergeyev, Sergey V; Rozhin, Aleksey

    2016-07-11

    An Erbium-doped fibre ring laser hybrid mode-locked with single-wall carbon nanotubes (SWNT) and nonlinear polarisation evolution (NPE) without an optical isolator has been investigated for various cavity conditions. Precise control of the state of polarisation (SOP) in the cavity ensures different losses for counter-propagating optical fields. As the result, the laser operates in quasi-unidirectional regime in both clockwise (CW) and counter-clockwise (CCW) directions with the emission strengths difference of the directions of 22 dB. Furthermore, by adjusting the net birefringence in the cavity, the laser can operate in a bidirectional generation. In this case, a laser pumped with 75 mW power at 980 nm generates almost identical 790 and 570 fs soliton pulses with an average power of 1.17 and 1.11 mW. The operation stability and pulse quality of the soliton pulses in both unidirectional regimes are highly competitive with those generated in conventional ring fibre lasers with isolator in the cavity. Demonstrated bidirectional laser operation can find vital applications in gyroscopes or precision rotation sensing technologies. PMID:27410844

  12. Temperature-Insensitive Bend Sensor Using Entirely Centered Erbium Doping in the Fiber Core

    PubMed Central

    Ahmad, Harith; Zulkifli, Mohd Zamani; Muhammad, Farah Diana; Samangun, Julian Md; Abdul-Rashid, Hairul Azhar; Harun, Sulaiman Wadi

    2013-01-01

    A fiber based bend sensor using a uniquely designed Bend-Sensitive Erbium Doped Fiber (BSEDF) is proposed and demonstrated. The BSEDF has two core regions, namely an undoped outer region with a diameter of about 9.38 μm encompassing a doped, inner core region with a diameter of 4.00 μm. The doped core region has about 400 ppm of an Er2O3 dopant. Pumping the BSEDF with a conventional 980 nm laser diode gives an Amplified Spontaneous Emission (ASE) spectrum spanning from 1,510 nm to over 1,560 nm at the output power level of about −58 dBm. The ASE spectrum has a peak power of −52 dBm at a central wavelength of 1,533 nm when not spooled. Spooling the BSEDF with diameters of 10 cm to 2 cm yields decreasing peak powers from −57.0 dBm to −61.8 dBm, while the central wavelength remains unchanged. The output is highly stable over time, with a low temperature sensitivity of around ∼0.005 dBm/°C, thus allowing for the development of a highly stable sensor system based in the change of the peak power alone. PMID:23881146

  13. Erbium doping into silicate glasses to form luminescent optical layers for photonics applications

    NASA Astrophysics Data System (ADS)

    Salavcova, Linda; Mackova, Anna; Oswald, Jiri; Svecova, Blanka; Janakova, Stanislava; Spirkova, Jarmila; Mika, Martin

    2007-05-01

    Here we summarise results of our research on the Er-containing thin surface layers in the silicate glasses and on the effect of the layers’ composition on their luminescence properties (emission at 1535 nm) in the wavelength region widely used in photonics. The optical layers were fabricated by Er3+ (melt)⇔Li+/Na+ (glass substrate) ion exchange in the specially designed Li2O containing silicate glasses using various conditions (including annealing of the samples) to obtain a set of layers with diverse distribution of the Er3+ ions. Changes in the chemical composition of the prepared layers were suggested to avoid the concentration quenching effect and to improve their luminescence properties; special attention was paid to presence of hydrogen in the layers that may decrease the emission intensity. Rutherford Backscattering Spectroscopy and Elastic Recoil Detection were used to obtain detailed information on migration of erbium and hydrogen through the glass matrix, respectively. Photoluminescence spectra of the fabricated samples were measured (excitation at 980 nm) to examine the desired emission around 1535 nm.

  14. Laser-diode-pumped, erbium-doped, solid-state laser with high slope efficiency

    SciTech Connect

    Esterowitz, L.; Allen, R.; Kintz, G.

    1989-10-31

    A laser and method for producing a laser emission at a wavelength of substantially 2.8 microns is disclosed. In a preferred embodiment of the invention, the laser comprises laser diode means for emitting a pump beam at a preselected wavelength; and a crystal having a preselected host material doped with a predetermined percent concentration of erbium activator ions sufficient to produce a laser emission at substantially 2.8 microns at a slope efficiency of at least 5 percent, but preferrably 10 percent, when the crystal is pumped by the pump beam. It is well known that the human body is comprised of approximately 70% water, with various human tissues containing about 60% to 90% of water, and bone and cartilage containing about 30% to 40% of water. Since the 2.8 micron wavelength has a substantially maximum absorption in water, this 2.8 micron wavelength is the ideal wavelength to use for a large variety of medical laser applications on the human body. A 2.8 micron wavelength laser could be used for precise surgery in such exemplary applications as brain surgery, neurosurgery, eye surgery, plastic surgery, burn treatment and the removal of malignancies.

  15. Q-switched Erbium-doped fiber laser at 1600 nm for photoacoustic imaging application

    NASA Astrophysics Data System (ADS)

    Piao, Zhonglie; Zeng, Lvming; Chen, Zhongping; Kim, Chang-Seok

    2016-04-01

    We present a nanosecond Q-switched Erbium-doped fiber (EDF) laser system operating at 1600 nm with a tunable repetition rate from 100 kHz to 1 MHz. A compact fiber coupled, acousto-optic modulator-based EDF ring cavity was used to generate a nanosecond seed laser at 1600 nm, and a double-cladding EDF based power amplifier was applied to achieve the maximum average power of 250 mW. In addition, 12 ns laser pulses with the maximum pulse energy of 2.4 μJ were obtained at 100 kHz. Furthermore, the Stokes shift by Raman scattering over a 25 km long fiber was measured, indicating that the laser can be potentially used to generate the high repetition rate pulses at the 1.7 μm region. Finally, we detected the photoacoustic signal from a human hair at 200 kHz repetition rate with a pulse energy of 1.2 μJ, which demonstrates that a Q-switched Er-doped fiber laser can be a promising light source for the high speed functional photoacoustic imaging.

  16. Temporal characterization of a multi-wavelength Brillouin–erbium fiber laser

    NASA Astrophysics Data System (ADS)

    Lambin Iezzi, Victor; Büttner, Thomas F. S.; Tehranchi, Amirhossein; Loranger, Sébastien; Kabakova, Irina V.; Eggleton, Benjamin J.; Kashyap, Raman

    2016-05-01

    This paper provides the first detailed temporal characterization of a multi-wavelength-Brillouin–erbium fiber laser (MWBEFL) by measuring the optical intensity of the individual frequency channels with high temporal resolution. It is found that the power in each channel is highly unstable due to the excitation of several cavity modes for typical conditions of operation. Also provided is the real-time measurements of the MWBEFL output power for two configurations that were previously reported to emit phase-locked picosecond pulse trains, concluded from their autocorrelation measurements. Real-time measurements reveal a high degree of instability without the formation of a stable pulse train. Finally, we model the MWBEFL using coupled wave equations describing the evolution of the Brillouin pump, Stokes and acoustic waves in the presence of stimulated Brillouin scattering, and the optical Kerr effect. A good qualitative consistency between the simulation and experimental results is evident, in which the interference signal at the output shows strong instability as well as the chaotic behavior due to the dynamics of participating pump and Stokes waves.

  17. Laser sclerostomy ab externo with the Erbium:YAG laser using a new flexible application system

    NASA Astrophysics Data System (ADS)

    Wetzel, Wolfgang; Scheu, M.; Brinkmann, Ralf; Birngruber, Reginald

    1992-08-01

    A fistula from the anterior chamber of the eye into the subconjunctival space can be created by laser application ab externo (laser sclerostomy). The success of the procedure mainly depends on the special application system. The pulsed Erbium-YAG laser (2940 nm) was used as the energy source. The laser energy was guided to the application system via a ZrFl fiber with low attenuation at this wavelength. Because this fiber cannot be used in direct contact to the sclera, an optical coupling unit transmitted the energy to a short quartz fiber. This fiber was inserted in a specially sharpened retractable cannula to guide it into the subconjunctival space. Then the laser energy could be applied directly to the sclera to form the fistula. The procedure was demonstrated in vivo using rabbit eyes. A working fistula with formation of a filtering bleb could be achieved. The trauma to the conjunctiva was as minimal as in a subconjunctival injection. The minor alteration of the conjunctiva in this procedure compared to traditional surgical methods like goniotrepanation or trabeculectomy may cause less scarification and therefore less failure.

  18. Oxygen-impurity interactions in crystalline silicon: The cases of aluminum and erbium

    NASA Astrophysics Data System (ADS)

    Rimini, E.; La Ferla, A.; Galvagno, G.; Coffa, S.; Franzò, G.; Priolo, F.

    1997-01-01

    Impurities such as oxygen and carbon have a strong influence on the electrical and optical behaviour of other species introduced in Si. The influence can be either beneficial or detrimental according to the considered case. Two different examples are discussed in the present paper. The electrical activity of ion implanted Al, the fastest diffusing p-type dopant, amounts to a few percent of the fluence in Czochralski wafers while is practically unity in epitaxial or float-zone wafers, having a low content of dissolved oxygen. This behaviour is accounted for in terms of AlO inactive complexes whose formation is enhanced by defects. Good activation and deep junctions can be obtained by avoiding the simultaneous presence of O and defects. Erbium ions introduced by ion implantation in Si are optically active with an emission at 1.54 μm. The luminescence, however, strongly quenches with temperature and room temperature emission cannot be achieved. The co-introduction of Er and O, with the subsequent formation of ErO complexes in Si, strongly reduces this temperature quenching and room temperature light emission can be easily achieved. These two cases are presented and possible applications discussed.

  19. Characterization and modeling of a dispersive cavity mode-locked erbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Hayduk, Michael J.; Haus, Joseph W.; Kaechele, Walter; Shaulov, Gary; Teegarden, Kenneth J.; Theimer, James P.; Wicks, Gary W.

    1999-07-01

    A novel, compact, polarization insensitive mode-locked erbium-doped fiber laser producing 2 ps pulses was constructed. The laser was passively mode-locked using a 75 period InGaAs/InAlAs multiple quantum well saturable absorber grown lattice matched on an InP substrate. The laser was constructed in a linear cavity, Fabry-Perot configuration with the saturable absorber at one end of the cavity and a chirped fiber Bragg grating at the other end. The output pulses are chirped and were further characterized by varying their energies and propagating them down different lengths of standard optical fiber. The laser cavity was modeled using the complex Ginzburg-Landau equation derived under the condition that nonlinear changes to the pulse must be small per round-trip. The contribution of the semiconductor saturable absorber was modeled using a two-level rate equation. The free carrier absorption within the semiconductor contributes to the refractive index which was shown numerically to result in an additional frequency shift. The modeling is in close agreement with the pulse propagation experiments.

  20. Double-clad erbium/ytterbium-doped fiber laser with a fiber Bragg grating

    NASA Astrophysics Data System (ADS)

    Moghaddam, M. R. A.; Harun, S. W.; Tamjis, M. R.; Ahmad, H.

    2009-08-01

    A double-clad erbium/ytterbium-doped fiber laser (EYDFL) is demonstrated using a fiber Bragg grating (FBG) as wavelength selective filter in a linear cavity resonator. The effect of the FBG's wavelength on the performance of the EYDFL is also investigated. The slope efficiencies of the EYDFL are obtained at 33.7%, 30.9%, and 24.1% for the operating wavelengths of 1553.6, 1557.3, and 1562.8 nm, respectively. The efficiency is higher with a shorter wavelength due to the amplification characteristic of the EYDF which peaks at 1545 nm. At FBG's wavelength of 1553.6 nm, the EYDFL has an output power of 520 mW when pumped at 1700 mW by a 937 nm laser diode. The laser also has a spectral bandwidth of 0.2 nm and signal to noise ratio of more than 25 dB. The threshold power to achieve lasing is measured to be approximately 90 mW for this laser.