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Sample records for lithium niobate waveguide

  1. Quantum photonics at telecom wavelengths based on lithium niobate waveguides

    NASA Astrophysics Data System (ADS)

    Alibart, Olivier; D'Auria, Virginia; De Micheli, Marc; Doutre, Florent; Kaiser, Florian; Labonté, Laurent; Lunghi, Tommaso; Picholle, Éric; Tanzilli, Sébastien

    2016-10-01

    Integrated optical components on lithium niobate play a major role in standard high-speed communication systems. Over the last two decades, after the birth and positioning of quantum information science, lithium niobate waveguide architectures have emerged as one of the key platforms for enabling photonics quantum technologies. Due to mature technological processes for waveguide structure integration, as well as inherent and efficient properties for nonlinear optical effects, lithium niobate devices are nowadays at the heart of many photon-pair or triplet sources, single-photon detectors, coherent wavelength-conversion interfaces, and quantum memories. Consequently, they find applications in advanced and complex quantum communication systems, where compactness, stability, efficiency, and interconnectability with other guided-wave technologies are required. In this review paper, we first introduce the material aspects of lithium niobate, and subsequently discuss all of the above mentioned quantum components, ranging from standard photon-pair sources to more complex and advanced circuits.

  2. Nonlinear diffusion model for annealed proton-exchanged waveguides in zirconium-doped lithium niobate.

    PubMed

    Langrock, Carsten; Roussev, Rostislav V; Nava, Giovanni; Minzioni, Paolo; Argiolas, Nicola; Sada, Cinzia; Fejer, Martin M

    2016-08-20

    Photorefractive-damage- (PRD) resistant zirconium-oxide-doped lithium niobate is investigated as a substrate for the realization of annealed proton-exchanged (APE) waveguides. Its advantages are a favorable distribution coefficient, PRD resistance comparable to magnesium-oxide-doped lithium niobate, and a proton-diffusion behavior resembling congruent lithium niobate. A 1D model for APE waveguides was developed based on a previous model for congruently melting lithium niobate. Evidence for a nonlinear index dependence on concentration was found.

  3. Optical waveguides in lithium niobate: Recent developments and applications

    SciTech Connect

    Bazzan, Marco Sada, Cinzia

    2015-12-15

    The state of the art of optical waveguide fabrication in lithium niobate is reviewed, with particular emphasis on new technologies and recent applications. The attention is mainly devoted to recently developed fabrication methods, such as femtosecond laser writing, ion implantation, and smart cut waveguides as well as to the realization of waveguides with tailored functionalities, such as photorefractive or domain engineered structures. More exotic systems, such as reconfigurable and photorefractive soliton waveguides, are also considered. Classical techniques, such as Ti in-diffusion and proton exchange, are cited and briefly reviewed as a reference standpoint to highlight the recent developments. In all cases, the application-oriented point of view is preferred, in order to provide the reader with an up-to date panorama of the vast possibilities offered by lithium niobate to integrated photonics.

  4. Neutron depth profiling study of lithium niobate optical waveguides

    NASA Astrophysics Data System (ADS)

    Kolářova, P.; Vacík, J.; Špirková-Hradilová, J.; Červená, J.

    1998-05-01

    The relation between optical properties and the structure of proton exchanged and annealed proton exchanged optical waveguides in lithium niobate was studied using the mode spectroscopy and neutron depth profiling methods. We have found a close correlation between the lithium depletion and the depth profile of the extraordinary refractive index. The form of the observed dependence between Li depletion and refractive index depends on the fabrication procedure by which the waveguide was prepared but it is highly reproducible for specimens prepared by the same procedure.

  5. Lithium niobate integrated photonic crystal and waveguides

    NASA Astrophysics Data System (ADS)

    Lim, Soon Thor; Ang, Thomas Y.-L.; Png, Ching Eng; Deng, Jun; Danner, Aaron J.

    2016-02-01

    In this work we successfully fabricated and measured PhCs patterned on a LiNbO3 APE waveguide. SIMS data indicate that after 5 hours exchange time a PE layer of 3μm can be obtained. The depth of holes was 2μm by applying a large milling current. We presented experimental characterization of the PhC waveguide and a well-defined PBG was observed from the transmission spectra. An extinction ratio was estimated to be approximately 15dB. Optical transmission results indicate that deep air holes can lead to a sharp band edge. This PhC waveguide is a good candidate for further development of an ultra-compact, low-voltage LiNbO3 modulator.

  6. Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate

    NASA Technical Reports Server (NTRS)

    Himmer, Phillip; Battle, Philip; Suckow, William; Switzer, Greg

    2011-01-01

    This work proposes to establish the feasibility of fabricating isolated ridge waveguides in 5% MgO:LN. Ridge waveguides in MgO:LN will significantly improve power handling and conversion efficiency, increase photonic component integration, and be well suited to spacebased applications. The key innovation in this effort is to combine recently available large, high-photorefractive-damage-threshold, z-cut 5% MgO:LN with novel ridge fabrication techniques to achieve high-optical power, low-cost, high-volume manufacturing of frequency conversion structures. The proposed ridge waveguide structure should maintain the characteristics of the periodically poled bulk substrate, allowing for the efficient frequency conversion typical of waveguides and the high optical damage threshold and long lifetimes typical of the 5% doped bulk substrate. The low cost and large area of 5% MgO:LN wafers, and the improved performance of the proposed ridge waveguide structure, will enhance existing measurement capabilities as well as reduce the resources required to achieve high-performance specifications. The purpose of the ridge waveguides in MgO:LN is to provide platform technology that will improve optical power handling and conversion efficiency compared to existing waveguide technology. The proposed ridge waveguide is produced using standard microfabrication techniques. The approach is enabled by recent advances in inductively coupled plasma etchers and chemical mechanical planarization techniques. In conjunction with wafer bonding, this fabrication methodology can be used to create arbitrarily shaped waveguides allowing complex optical circuits to be engineered in nonlinear optical materials such as magnesium doped lithium niobate. Researchers here have identified NLO (nonlinear optical) ridge waveguide structures as having suitable value to be the leading frequency conversion structures. Its value is based on having the low-cost fabrication necessary to satisfy the challenging pricing

  7. Formation of waveguide channels by dark spatial solitons in a planar waveguide optically induced in a lithium niobate crystal

    SciTech Connect

    Shandarov, V M; Shandarova, K V

    2005-10-31

    The formation of optical waveguide channels is experimentally demonstrated upon the photorefractive self-action of a phased light beam in a planar waveguide optically induced in an iron-doped lithium niobate crystal. Planar and channel waveguides were produced by using a 633-nm He-Ne laser with output powers 1 mW and {approx}10 {mu}W, respectively. (waveguides)

  8. Tailoring entanglement through domain engineering in a lithium niobate waveguide

    PubMed Central

    Ming, Yang; Tan, Ai-Hong; Wu, Zi-Jian; Chen, Zhao-Xian; Xu, Fei; Lu, Yan-Qing

    2014-01-01

    We propose to integrate the electro-optic (EO) tuning function into on-chip domain engineered lithium niobate (LN) waveguide. Due to the versatility of LN, both the spontaneously parametric down conversion (SPDC) and EO interaction could be realized simultaneously. Photon pairs are generated through SPDC, and the formation of entangled state is modulated by EO processes. An EO tunable polarization-entangled photon state is proposed. Orthogonally-polarized and parallel-polarized entanglements of photon pairs are instantly switchable by tuning the applied field. The characteristics of the source are theoretically investigated showing adjustable bandwidths and high entanglement degrees. Moreover, other kinds of reconfigurable entanglement are also achievable based on suitable domain-design. We believe tailoring entanglement based on domain engineering is a very promising solution for next generation function-integrated quantum circuits. PMID:24770555

  9. Periodic domain patterning by electron beam of proton exchanged waveguides in lithium niobate

    SciTech Connect

    Chezganov, D. S. Shur, V. Ya.; Vlasov, E. O.; Neradovskiy, M. M.; Gimadeeva, L. V.; Neradovskaya, E. A.; Chuvakova, M. A.; Tronche, H.; Doutre, F.; Baldi, P.; De Micheli, M. P.

    2016-05-09

    Formation of domain structure by electron beam irradiation in congruent lithium niobate covered by surface dielectric layer with planar and channel waveguides produced by Soft Proton Exchange (SPE) process has been studied. Formation of domains with arbitrary shapes as a result of discrete switching has been revealed. The fact was attributed to ineffective screening of depolarization field in the crystals with a surface layer modified by SPE process. The dependences of the domain sizes on the dose and the distance between irradiated areas have been revealed. Finally, we have demonstrated that electron beam irradiation of lithium niobate crystals with surface resist layer can produce high quality periodical domain patterns after channel waveguide fabrication. Second harmonic generation with normalized nonlinear conversion efficiency up to 48%/(W cm{sup 2}) has been achieved in such waveguides.

  10. Annealed proton exchanged optical waveguides in lithium niobate: differences between the X- and Z-cuts

    NASA Astrophysics Data System (ADS)

    Nekvindová, Pavla; Špirková, Jarmila; Červená, Jarmila; Budnar, Milos; Razpet, Alenka; Zorko, Benjamin; Pelicon, Primož

    2002-04-01

    This article summarizes results and assessments of our systematic fabrication and characterization of proton exchanged (PE) and annealed proton exchanged (APE) waveguides study in lithium niobate. This study focused on different behavior of crystallographically diverse X(1 1 2¯ 0) and Z(0 0 0 1) substrate cuts during waveguides fabrication, and differences in characteristics of the resulting waveguides. Non-toxic adipic acid was used as a proton source, and the waveguides properties were defined by a mode spectroscopy (waveguides characteristics) and neutron depth profiling (NDP, lithium concentration and distribution), infrared vibration spectra and elastic recoil detection analysis (ERDA, concentration and depth distribution of hydrogen). It was discovered that the X-cuts structure is more permeable for moving particles (lithium and hydrogen ions), which leads to a higher effectiveness of the PE process within the X-cut. The explanation of this phenomenon is based on the fitting X-cuts orientation towards cleavage planes of lithium niobate crystal. Higher content of interstitial hydrogen in the X-cuts then prevents lithium from free movement during the post-exchange annealing in direction to the surface of samples, and so causes a typical step-like shape of the depth concentration profiles of lithium within the X-cuts. A free transport of lithium within the Z-cuts is being reflected in a gradient shape of the lithium depth concentration profiles and extraordinary refractive index, as well the last but not least, in a trouble-free good reproducibility of the waveguides fabrication within the Z-cuts.

  11. Fast path and polarization manipulation of telecom wavelength single photons in lithium niobate waveguide devices.

    PubMed

    Bonneau, Damien; Lobino, Mirko; Jiang, Pisu; Natarajan, Chandra M; Tanner, Michael G; Hadfield, Robert H; Dorenbos, Sanders N; Zwiller, Val; Thompson, Mark G; O'Brien, Jeremy L

    2012-02-03

    We demonstrate fast polarization and path control of photons at 1550 nm in lithium niobate waveguide devices using the electro-optic effect. We show heralded single photon state engineering, quantum interference, fast state preparation of two entangled photons, and feedback control of quantum interference. These results point the way to a single platform that will enable the integration of nonlinear single photon sources and fast reconfigurable circuits for future photonic quantum information science and technology.

  12. Surface acoustic waves in acoustic superlattice lithium niobate coated with a waveguide layer

    NASA Astrophysics Data System (ADS)

    Yang, G. Y.; Du, J. K.; Huang, B.; Jin, Y. A.; Xu, M. H.

    2017-04-01

    The effects of the waveguide layer on the band structure of Rayleigh waves are studied in this work based on a one-dimensional acoustic superlattice lithium niobate substrate coated with a waveguide layer. The present phononic structure is formed by the periodic domain-inverted single crystal that is the Z-cut lithium niobate substrate with a waveguide layer on the upper surface. The plane wave expansion method (PWE) is adopted to determine the band gap behavior of the phononic structure and validated by the finite element method (FEM). The FEM is also used to investigate the transmission of Rayleigh waves in the phononic structure with the interdigital transducers by means of the commercial package COMSOL. The results show that, although there is a homogeneous waveguide layer on the surface, the band gap of Rayleigh waves still exist. It is also found that increasing the thickness of the waveguide layer, the band width narrows and the band structure shifts to lower frequency. The present approach can be taken as an efficient tool in designing of phononic structures with waveguide layer.

  13. OTDM to WDM format conversion based on quadratic cascading in a periodically poled lithium niobate waveguide.

    PubMed

    Lee, Kwang Jo; Liu, Sheng; Parmigiani, Francesca; Ibsen, Morten; Petropoulos, Periklis; Gallo, Katia; Richardson, David J

    2010-05-10

    We propose and demonstrate error-free conversion of a 40 Gbit/s optical time division multiplexed signal to 4 x 10 Gbit/s wavelength division multiplexed channels based on cascaded second harmonic and difference frequency generation in a periodically poled lithium niobate waveguide. The technique relies on the generation of spectrally (and temporally) flat linearly chirped pulses which are then optically switched with short data pulses in the nonlinear waveguide. Error-free operation was obtained for all channels with a power penalty below 2dB.

  14. Optical amplifier based on an Er:MgO-doped near stoichiometric lithium niobate waveguide

    NASA Astrophysics Data System (ADS)

    Ma, Linan; Tan, Yang; Chen, Feng

    2017-07-01

    We report on an optical signal amplifier based on an Er:MgO-doped near stoichiometric lithium niobate (Er:MgO:SLN) waveguide. The Er:MgO:SLN waveguide was fabricated using swift carbon ion irradiation combined with precision diamond blade dicing. Under 980 nm laser pumping, the waveguide provides a 2.13 dB/cm gain at 1536 nm, 1.49 dB/cm gain at 1552 nm, and 1.37 dB/cm gain at 1565 nm, with the pumping power of 99.5 mW. This work demonstrates the potential application of swift ion irradiated Er:MgO:SLN waveguides for the optical amplifiers in the C communication band.

  15. Phase sensitive amplification based on quadratic cascading in a periodically poled lithium niobate waveguide.

    PubMed

    Lee, Kwang Jo; Parmigiani, Francesca; Liu, Sheng; Kakande, Joseph; Petropoulos, Periklis; Gallo, Katia; Richardson, David

    2009-10-26

    We propose and demonstrate phase-sensitive amplification based on cascaded second harmonic generation and difference frequency generation within a periodically poled lithium niobate waveguide. Excellent agreement between our numerical simulations and proof-of-principle experiments using a 3-cm waveguide device operating at wavelengths around 1550 nm is obtained. Our experiments confirm the validity and practicality of the approach and illustrate the broad gain bandwidths achievable. Additional simulation results show that the maximum gain/attenuation factor increases quadratically with input pump power, reaching a value of +/- 19.0 dB at input pump powers of 33 dBm for a 3 cm-long waveguide. Increased gains/reduced powers for a fixed gain could be achieved using longer crystals.

  16. Fabrication and investigation of TIPE waveguide lenses based on lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Volkov, V. A.; Vyrelkin, V. P.; Gan'shin, V. A.; Kvasha, M. Iu.; Korkishko, Iu. N.

    1987-06-01

    The titanium-interdiffused-proton-exchange (TIPE) process for fabricating waveguide lenses is briefly characterized, and a simpler version of the process is proposed. In this process, a single-mode (wavelength, 0.63 micron) Ti:LiNbO3 waveguide is diffused onto the Y-section of lithium niobate at 980 C for 6 hr. An SiO-SiO2 film is then deposited on the crystal surface which serves as a mask for proton-exchange diffusion. Proton exchange diffusion is carried out in the melts of some stable acid salts, making it possible to fabricate TIPE waveguides in open crucibles in air rather than inside evacuated containers. Experimental results are presented for three hyperbolic structures fabricated by the process described here.

  17. Rapid thermal annealing in high repetition rate ultrafast laser waveguide writing in lithium niobate.

    PubMed

    Nejadmalayeri, Amir H; Herman, Peter R

    2007-08-20

    For the first time to our knowledge, bulk modification of lithium niobate using high repetition rate ultrashort laser pulses has been studied. A fiber based ultrafast laser has been applied in a range of 0.1 to 1.5 MHz repetition rate to directly inscribe optical waveguides in z-cut lithium niobate. Circularly polarized light with stretched 600 fs pulses produced waveguides with nearly circular mode profiles that guided in the telecom band of 1300 nm. Higher laser repetition rate of 700 kHz was found to offer smooth waveguides with low propagation loss of 0.6 dB/cm, matching the best reported value so far, with the advantage of 50 fold faster writing speed. At repetition rates of 250 kHz and higher, the tracks exhibited a cladding-like modification zone that extended outside the main laser interaction volume, yielding smoother structures, despite higher net fluence delivery, providing concrete evidence of heat accumulation and thermal annealing effects. We also present the first observation of periodic micro-structures in the bulk laser interaction volume of a non-glass material.

  18. Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

    DOE PAGES

    Weigel, Peter O.; Savanier, Marc; DeRose, Christopher T.; ...

    2016-03-01

    Here, we demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneathmore » an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.« less

  19. Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

    SciTech Connect

    Weigel, Peter O.; Savanier, Marc; DeRose, Christopher T.; Pomerene, Andrew T.; Starbuck, Andrew L.; Lentine, Anthony L.; Stenger, Vincent; Mookherjea, Shayan

    2016-03-01

    Here, we demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost.

  20. Lightwave Circuits in Lithium Niobate through Hybrid Waveguides with Silicon Photonics

    PubMed Central

    Weigel, Peter O.; Savanier, Marc; DeRose, Christopher T.; Pomerene, Andrew T.; Starbuck, Andrew L.; Lentine, Anthony L.; Stenger, Vincent; Mookherjea, Shayan

    2016-01-01

    We demonstrate a photonic waveguide technology based on a two-material core, in which light is controllably and repeatedly transferred back and forth between sub-micron thickness crystalline layers of Si and LN bonded to one another, where the former is patterned and the latter is not. In this way, the foundry-based wafer-scale fabrication technology for silicon photonics can be leveraged to form lithium-niobate based integrated optical devices. Using two different guided modes and an adiabatic mode transition between them, we demonstrate a set of building blocks such as waveguides, bends, and couplers which can be used to route light underneath an unpatterned slab of LN, as well as outside the LN-bonded region, thus enabling complex and compact lightwave circuits in LN alongside Si photonics with fabrication ease and low cost. PMID:26927022

  1. Fabrication of lithium niobate-based low-loss bend optical waveguide

    NASA Astrophysics Data System (ADS)

    Li, Xin; Liu, Ang; Qiu, Yu; Feng, Jie; Chen, Jun-Jiang; Lin, Xue-song; Yang, Shi-han; Zhou, Zi-gang

    2014-11-01

    The bend waveguide is one of the key components of photonic integration. In this paper, by using tightly focused femtosecond laser pulses with repetition rate of 76 MHz, pulse duration of 50 fs, average output power about 270mW, and the focus lens NA=0.65, we put forward a structure of waveguide that bent it to be 1/4 round, and research its mechanism by performing experiments. Under the above conditions, when the vertical scanning speed of the laser system is 0.8 mm / s, the width of the bend optical waveguide is about 10μm, the loss reaches a minimum value about 1dB/cm when the bend way's radius is about 5mm. Based on the experimental results of the above parameters, we can fabricate a 1/4 round vertical bend fiber coupler, which can be applied to the connection between the chips or inter-level optical .The results showed that the bend lithium niobate waveguides can be applied in the field of optical communication and has important implications for the production of low loss, low cost and small size optical waveguide gratings , vertical fiber coupler, optical switches and other devices .

  2. The combination methodic of diffusion and implantation technologies for creating optic wave-guided layers in lithium niobate

    NASA Astrophysics Data System (ADS)

    Orlikov, L. N.; Orlikov, N. L.; Arestov, S. I.; Mambetova, K. M.; Shandarov, S. M.

    2015-04-01

    The implantation of copper into Lithium Niobate in the prohibited crystal zone forms a definite energetic level for optic transits. This paper examines conditions of optic wave-guided layers formation on Niobate Lithium due to the method of implantation copper ions with the next diffusion. Reflect Spectrum in consequences implantation is extended. The transfer of the optical power from the primary beam into the another beam was discovered and in reverse. Photo galvanic characteristics of implantation specimen identity of crystal by traditional technology and doping CuO manufacture.

  3. Argon plasma inductively coupled plasma reactive ion etching study for smooth sidewall thin film lithium niobate waveguide application

    NASA Astrophysics Data System (ADS)

    Ulliac, G.; Calero, V.; Ndao, A.; Baida, F. I.; Bernal, M.-P.

    2016-03-01

    Lithium Niobate (LN) exhibits unique physical properties such as remarkable electro-optical coefficients and it is thus an excellent material for a wide range of fields like optic communications, lasers, nonlinear optical applications, electric field optical sensors etc. In order to further enhance the optical device performance and to be competitive with silicon photonics, sub-micrometric thickness lithium niobate films are crucial. A big step has been achieved with the development of LN thin films by using smart cut technology and wafer bonding and these films are nowadays available in the market. However, it is a challenge to obtain the requirements of the high quality thin LN film waveguide. In this letter, we show smooth ridge waveguides fabricated on 700 nm thickness thin film lithium niobate (TFLN). The fabrication has been done by developing and optimizing three steps of the technological process, the mask fabrication, the plasma etching, and a final cleaning wet etching step in order to remove the lithium niobate redeposition on the side walls. We have obtained single mode propagation with light overall losses of only 5 dB/cm.

  4. Reduced pulse energy for frequency comb offset stabilization with a dual-pitch periodically poled lithium niobate ridge waveguide

    NASA Astrophysics Data System (ADS)

    Hitachi, K.; Hara, K.; Tadanaga, O.; Ishizawa, A.; Nishikawa, T.; Gotoh, H.

    2017-06-01

    The pulse energy for stabilizing the carrier-envelop offset frequency of an Er-doped fiber laser was reduced by a dual-pitch (DP-) periodically poled lithium niobate (PPLN) ridge waveguide implemented in a 2f-to-3f self-referencing interferometer (SRI). The pulse energy requirement was less than half that for a single-pitch PPLN ridge waveguide implemented in an f-to-2f SRI. We also found that environmental noise could be reduced by adjusting the pulse energy for frequency stabilization with the DP-PPLN ridge waveguide, as estimated from the phase noise of an out-of-loop interferometer.

  5. Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing

    PubMed Central

    Wang, Peng; Qi, Jia; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2017-01-01

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 μm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing. PMID:28112246

  6. Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing.

    PubMed

    Wang, Peng; Qi, Jia; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2017-01-23

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 μm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing.

  7. Fabrication of polarization-independent waveguides deeply buried in lithium niobate crystal using aberration-corrected femtosecond laser direct writing

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Qi, Jia; Liu, Zhengming; Liao, Yang; Chu, Wei; Cheng, Ya

    2017-01-01

    Writing optical waveguides with femtosecond laser pulses provides the capability of forming three-dimensional photonic circuits for manipulating light fields in both linear and nonlinear manners. To fully explore this potential, large depths of the buried waveguides in transparent substrates are often desirable to facilitate achieving vertical integration of waveguides in a multi-layer configuration, which, however, is hampered by rapidly degraded axial resolution caused by optical aberration. Here, we show that with the correction of the spherical aberration, polarization-independent waveguides can be inscribed in a nonlinear optical crystal lithium niobate (LN) at depths up to 1400 μm, which is more than one order of magnitude deeper than the waveguides written with aberration uncorrected femtosecond laser pulses. Our technique is beneficial for applications ranging from miniaturized nonlinear light sources to quantum information processing.

  8. Monolithic integration of a lithium niobate microresonator with a free-standing waveguide using femtosecond laser assisted ion beam writing

    PubMed Central

    Fang, Zhiwei; Xu, Yingxin; Wang, Min; Qiao, Lingling; Lin, Jintian; Fang, Wei; Cheng, Ya

    2017-01-01

    We demonstrated integrating a high quality factor lithium niobate microdisk resonator with a free-standing membrane waveguide. Our technique is based on femtosecond laser direct writing which produces the pre-structure, followed by focused ion beam milling which reduces the surface roughness of sidewall of the fabricated structure to nanometer scale. Efficient light coupling between the integrated waveguide and microdisk was achieved, and the quality factor of the microresonator was measured as high as 1.67 × 105. PMID:28358135

  9. Electro-optical tunable waveguide embedded multiscan Bragg gratings in lithium niobate by direct femtosecond laser writing.

    PubMed

    Kroesen, Sebastian; Horn, Wolfgang; Imbrock, Jörg; Denz, Cornelia

    2014-09-22

    optical tunable Bragg gratings in lithium niobate fabricated by direct femtosecond laser writing. The hybrid design that consists of a circular type-II waveguide and a multiscan type-I Bragg grating exhibits low loss ordinary and extraordinary polarized guiding as well as narrowband reflections in the c-band of optical communications. High bandwidth tunability of more than a peak width and nearly preserved electro-optic coefficients of r(13) = 7.59 pm V(-1) and r(33) = 23.21 pm V(-1) are demonstrated.

  10. Enhanced Cherenkov phase matching terahertz wave generation via a magnesium oxide doped lithium niobate ridged waveguide crystal

    NASA Astrophysics Data System (ADS)

    Takeya, K.; Minami, T.; Okano, H.; Tripathi, S. R.; Kawase, K.

    2017-01-01

    When combined with a nonlinear waveguide crystal, Cherenkov phase matching allows for highly effective generation of high power and broadband terahertz (THz) waves. Using a ridged Lithium Niobate (LiNbO3) waveguide coupled with a specially designed silicon lens, we successfully generated THz waves with intensity of approximately three orders of magnitude stronger than those from conventional photoconductive antenna. The broadband spectrum was from 0.1 THz to 7 THz with a maximum dynamic range of 80 dB. The temporal shape of time domain pulse is a regular single cycle which could be used for high depth resolution time of flight tomography. The generated THz wave can also be easily monitored by compact room-temperature THz camera, enabling us to determine the spatial characteristics of the THz propagation.

  11. Frequency doubling of incoherent light from a superluminescent diode in a periodically poled lithium niobate waveguide crystal

    NASA Astrophysics Data System (ADS)

    Kurzke, Henning; Kiethe, Jan; Heuer, Axel; Jechow, Andreas

    2017-05-01

    The amplified spontaneous emission from a superluminescent diode was frequency doubled in a periodically poled lithium niobate waveguide crystal. The temporally incoherent radiation of such a superluminescent diode is characterized by a relatively broad spectral bandwidth and thermal-like photon statistics, as the measured degree of second order coherence, {{g}(2)}(0)=1.9+/- 0.1 , indicates. Despite the non-optimized scenario in the spectral domain, we achieve six orders of magnitude higher conversion efficiency than previously reported with truly incoherent light. This is possible by using single spatial mode radiation and quasi phase matched material with a waveguide architecture. This work is a principle step towards efficient frequency conversion of temporally incoherent radiation in one spatial mode to access wavelengths where no radiation from superluminescent diodes is available, especially with tailored quasi phase matched crystals. The frequency doubled light might find application in imaging, metrology and quantum optics experiments.

  12. Planar coupling to high-Q lithium niobate disk resonators.

    PubMed

    Nunzi Conti, G; Berneschi, S; Cosi, F; Pelli, S; Soria, S; Righini, G C; Dispenza, M; Secchi, A

    2011-02-14

    We demonstrate optical coupling to high-Q lithium niobate disks from an integrated lithium niobate waveguide. The waveguides are made by proton exchange in X-cut lithium niobate substrate. The disks with diameter of 4.7 mm and thickness of 1 mm are made from commercial Z-cut lithium niobate wafers by polishing the edges into a spheroidal profile. Both resonance linewidth and cavity ringdown measurements were performed to calculate the Q factor of the resonator, which is in excess of 10(8). Planar coupling represents the most promising technique for practical applications of whispering gallery mode resonators.

  13. Highly coherent mid-IR supercontinuum by self-defocusing solitons in lithium niobate waveguides with all-normal dispersion.

    PubMed

    Guo, Hairun; Zhou, Binbin; Zeng, Xianglong; Bache, Morten

    2014-05-19

    We numerically investigate self-defocusing solitons in a lithium niobate (LN) waveguide designed to have a large refractive index (RI) change. The waveguide evokes strong waveguide dispersion and all-normal dispersion is found in the entire guiding band spanning the near-IR and the beginning of the mid-IR. Meanwhile, a self-defocusing nonlinearity is invoked by the cascaded (phase-mismatched) second-harmonic generation under a quasi-phase-matching pitch. Combining this with the all-normal dispersion, mid-IR solitons can form and the waveguide presents the first all-nonlinear and solitonic device where no linear dispersion (i.e. non-solitonic) regimes exist within the guiding band. Soliton compressions at 2 μm and 3 μm are investigated, with nano-joule single cycle pulse formations and highly coherent octave-spanning supercontinuum generations. With an alternative design on the waveguide dispersion, the soliton spectral tunneling effect is also investigated, with which few-cycle pico-joule pulses at 2 μm are formed by a near-IR pump.

  14. Design of optical seven-segment decoder using Pockel's effect inside lithium niobate-based waveguide

    NASA Astrophysics Data System (ADS)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep

    2017-01-01

    Seven-segment decoder is a device that allows placing digital information from many inputs to many outputs optically, having 11 Mach-Zehnder interferometers (MZIs) for their implementation. The layout of the circuit is implemented to fit the electrical method on an optical logic circuit based on the beam propagation method (BPM). Seven-segment decoder is proposed using electro-optic effect inside lithium niobate-based MZIs. MZI structures are able to switch an optical signal to a desired output port. It consists of a mathematical explanation about the proposed device. The BPM is also used to analyze the study.

  15. Optical 1's and 2's complement devices using lithium-niobate-based waveguide

    NASA Astrophysics Data System (ADS)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep

    2016-12-01

    Optical 1's and 2's complement devices are proposed with the help of lithium-niobate-based Mach-Zehnder interferometers. It has a powerful capability of switching an optical signal from one port to the other port with the help of an electrical control signal. The paper includes the optical conversion scheme using sets of optical switches. 2's complement is common in computer systems and is used in binary subtraction and logical manipulation. The operation of the circuits is studied theoretically and analyzed through numerical simulations. The truth table of these complement methods is verified with the beam propagation method and MATLAB® simulation results.

  16. The possibility of tailoring the ne vs cLi relationship in lithium niobate optical waveguides

    NASA Astrophysics Data System (ADS)

    Špirková-Hradilová, Jarmila; Nekvindová, Pavla; Vacík, Jiří; Červená, Jarmila; Schröfel, Josef

    2001-01-01

    We present results of our study of concentration profiles of lithium ( cLi) in annealed proton exchanged (APE) waveguiding layers as measured by the neutron depth profiling (NDP) method. This non-destructive method, based on the 6Li(n,α) 3H reaction induced by thermal neutrons, allowed easy monitoring of cLi profiles in a large number of samples fabricated under various fabrication conditions. Our systematic study revealed that, though every particular waveguide could be characterised by very similar mirror-shaped extraordinary refractive index ( ne) as well as cLi depth profiles, in contrast with up to now generally accepted opinion, there was no linear relationship which unambiguously attributed Δne to ΔcLi. The most important fabrication step appeared to be the post-exchange annealing, during which the lithium atoms were transported towards the sample surfaces. The annealing regime pre-destined not only the depth distribution of the lithium atoms but, as a consequence of it, also other properties of the waveguiding region. That knowledge allows us to fabricate the APE waveguides with a priori given properties for a wide range of special applications. We have also formulated the ne vs cLi semi-empirical relationship, which was proved to fit all our fabricated APE waveguides.

  17. Bending waveguides made in x-cut lithium niobate crystals for technological applications

    NASA Astrophysics Data System (ADS)

    Guarepi, V.; Perrone, C.; Aveni, M.; Videla, F.; Torchia, GA

    2015-12-01

    In this paper we analyse the performance of several designs of integrated optical deviators made in x-cut lithium niobate crystals by means of femtosecond laser writing using the double line approach. Straight and bent guiding structures have been designed and implemented using this technique. Well-confined propagation modes at communication wavelengths (1.55 μm) were conducted in these structures with acceptable overall losses (less than 2 dB cm-1). Further, a discussion about the optical propagation losses for curved and straight deviators devices is included in this work. At a low aperture angle (less than 0.2°), as expected, low losses were determined for both structures; however, a weak output light was observed for large angles (greater than 0.2°) in the straight optical circuits. In contrast, a smooth variation of the output was measured for the bent structures. The results presented in this paper support the possibility of the technological implementation of integrated optical circuits for optical communications fabricated with ultrashort laser writing in lithium niobate crystals. In addition, some hypotheses of loss mechanisms that are normally not considered are discussed in order to explain the differences between the measured values and predictions obtained by calculating with the usual models.

  18. Integrated source of tunable nonmaximally mode-entangled photons in a domain-engineered lithium niobate waveguide

    SciTech Connect

    Ming, Yang; Wu, Zi-jian; Xu, Fei Lu, Yan-qing; Cui, Guo-xin; Tan, Ai-hong

    2014-04-28

    The nonmaximally entangled state is a special kind of entangled state, which has important applications in quantum information processing. It has been generated in quantum circuits based on bulk optical elements. However, corresponding schemes in integrated quantum circuits have been rarely considered. In this Letter, we propose an effective solution for this problem. An electro-optically tunable nonmaximally mode-entangled photon state is generated in an on-chip domain-engineered lithium niobate (LN) waveguide. Spontaneous parametric down-conversion and electro-optic interaction are effectively combined through suitable domain design to transform the entangled state into our desired formation. Moreover, this is a flexible approach to entanglement architectures. Other kinds of reconfigurable entanglements are also achievable through this method. LN provides a very promising platform for future quantum circuit integration.

  19. Integrated source of tunable nonmaximally mode-entangled photons in a domain-engineered lithium niobate waveguide

    NASA Astrophysics Data System (ADS)

    Ming, Yang; Wu, Zi-jian; Cui, Guo-xin; Tan, Ai-hong; Xu, Fei; Lu, Yan-qing

    2014-04-01

    The nonmaximally entangled state is a special kind of entangled state, which has important applications in quantum information processing. It has been generated in quantum circuits based on bulk optical elements. However, corresponding schemes in integrated quantum circuits have been rarely considered. In this Letter, we propose an effective solution for this problem. An electro-optically tunable nonmaximally mode-entangled photon state is generated in an on-chip domain-engineered lithium niobate (LN) waveguide. Spontaneous parametric down-conversion and electro-optic interaction are effectively combined through suitable domain design to transform the entangled state into our desired formation. Moreover, this is a flexible approach to entanglement architectures. Other kinds of reconfigurable entanglements are also achievable through this method. LN provides a very promising platform for future quantum circuit integration.

  20. Frequency conversion between UV and telecom wavelengths in a lithium niobate waveguide for quantum communication with Yb+ trapped ions

    NASA Astrophysics Data System (ADS)

    Kasture, Sachin; Lenzini, Francesco; Haylock, Ben; Boes, Andreas; Mitchell, Arnan; Streed, Erik W.; Lobino, Mirko

    2016-10-01

    We study and demonstrate the frequency conversion of UV radiation, resonant with 369.5 nm transition in Yb+ ions to the C-band wavelength 1580.3 nm and vice-versa using a reverse proton-exchanged waveguide in periodically poled lithium niobate. Our integrated device can interface trapped Yb+ ions with a telecom infrastructure for the realization of an Yb+ based quantum repeater protocol and to efficiently distribute entanglement over long distances. We analyse the single photon frequency conversion efficiency from the 369.525 nm to the telecom wavelength and its dependence on pump power, device length and temperature. The single-photon noise generated by the spontaneous Raman scattering of the pump is also measured. From this analysis we estimate a single photon conversion efficiency of ∼9% is achievable with our technology with almost complete suppression of the Raman noise.

  1. Reducing the thermal stress in a heterogeneous material stack for large-area hybrid optical silicon-lithium niobate waveguide micro-chips

    NASA Astrophysics Data System (ADS)

    Weigel, P. O.; Mookherjea, S.

    2017-04-01

    The bonding of silicon-on-insulator (SOI) to lithium niobate-on-insulator (LNOI) is becoming important for a new category of linear and nonlinear micro-photonic optical devices. In studying the bonding of SOI to LNOI through benzocyclobutene (BCB), a popular interlayer bonding dielectric used in hybrid silicon photonic devices, we use thermal stress calculations to suggest that BCB thickness does not affect thermal stress in this type of structure, and instead, thermal stress can be mitigated satisfactorily by matching the handles of the SOI and LNOI. We bond LNOI with a silicon handle to a silicon chip, remove the handle on the LNOI side, and thermally cycle the bonded stack repeatedly from room temperature up to 300°C and back down without incurring thermal stress cracks, which do appear when using LNOI with a lithium niobate handle, regardless of the BCB thickness. We show that this process can be used to create many hybrid silicon-lithium niobate waveguiding structures on a single patterned SOI chip bonded to a large-area (16 mm × 4.2 mm) lithium niobate film.

  2. Offset-Free Gigahertz Midinfrared Frequency Comb Based on Optical Parametric Amplification in a Periodically Poled Lithium Niobate Waveguide

    NASA Astrophysics Data System (ADS)

    Mayer, A. S.; Phillips, C. R.; Langrock, C.; Klenner, A.; Johnson, A. R.; Luke, K.; Okawachi, Y.; Lipson, M.; Gaeta, A. L.; Fejer, M. M.; Keller, U.

    2016-11-01

    We report the generation of an optical-frequency comb in the midinfrared region with 1-GHz comb-line spacing and no offset with respect to absolute-zero frequency. This comb is tunable from 2.5 to 4.2 μ m and covers a critical spectral region for important environmental and industrial applications, such as molecular spectroscopy of trace gases. We obtain such a comb using a highly efficient frequency conversion of a near-infrared frequency comb. The latter is based on a compact diode-pumped semiconductor saturable absorber mirror-mode-locked ytterbium-doped calcium-aluminum gadolynate (Yb:CALGO) laser operating at 1 μ m . The frequency-conversion process is based on optical parametric amplification (OPA) in a periodically poled lithium niobate (PPLN) chip containing buried waveguides fabricated by reverse proton exchange. The laser with a repetition rate of 1 GHz is the only active element of the system. It provides the pump pulses for the OPA process as well as seed photons in the range of 1.4 - 1.8 μ m via supercontinuum generation in a silicon-nitride (Si3 N4 ) waveguide. Both the PPLN and Si3 N4 waveguides represent particularly suitable platforms for low-energy nonlinear interactions; they allow for mid-IR comb powers per comb line at the microwatt level and signal amplification levels up to 35 dB, with 2 orders of magnitude less pulse energy than reported in OPA systems using bulk devices. Based on numerical simulations, we explain how high amplification can be achieved at low energy using the interplay between mode confinement and a favorable group-velocity mismatch configuration where the mid-IR pulse moves at the same velocity as the pump.

  3. Lithium niobate explosion monitor

    DOEpatents

    Bundy, Charles H.; Graham, Robert A.; Kuehn, Stephen F.; Precit, Richard R.; Rogers, Michael S.

    1990-01-01

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier.

  4. Lithium niobate explosion monitor

    DOEpatents

    Bundy, C.H.; Graham, R.A.; Kuehn, S.F.; Precit, R.R.; Rogers, M.S.

    1990-01-09

    Monitoring explosive devices is accomplished with a substantially z-cut lithium niobate crystal in abutment with the explosive device. Upon impact by a shock wave from detonation of the explosive device, the crystal emits a current pulse prior to destruction of the crystal. The current pulse is detected by a current viewing transformer and recorded as a function of time in nanoseconds. In order to self-check the crystal, the crystal has a chromium film resistor deposited thereon which may be heated by a current pulse prior to detonation. This generates a charge which is detected by a charge amplifier. 8 figs.

  5. Analysis of acceptable spectral windows of quadratic cascaded nonlinear processes in a periodically poled lithium niobate waveguide.

    PubMed

    Lee, Kwang Jo; Liu, Sheng; Gallo, Katia; Petropoulos, Periklis; Richardson, David J

    2011-04-25

    We report a systematic and comparative study of the acceptance bandwidths of two cascaded quadratic nonlinear processes in periodically poled lithium niobate waveguides, namely cascaded second-harmonic generation and difference-frequency generation (cSHG/DFG) and cascaded sum-frequency generation and difference-frequency generation (cSFG/DFG). We first theoretically and experimentally study the acceptance bandwidths of both the individual second-harmonic generation (SHG) and sum-frequency generation (SFG) processes in the continuous wave (CW) and pulsed-pump regimes. Our results show that the SHG bandwidth is approximately half that of the SFG process in the CW regime, whereas the SHG acceptance bandwidth can approach the CW SFG bandwidth limit when pulsed-pump is used. As a consequence we conclude that the tuning bandwidths of both cascaded processes should be similar in the pulsed pump regime once the pump pulse bandwidths approach that of SFG (i.e. the cSHG/DFG bandwidth is not limited by the CW SHG bandwidth). We confirm that this is the case experimentally.

  6. Characterization of diced ridge waveguides in pure and Er-doped lithium-niobate-on-insulator (LNOI) substrates

    NASA Astrophysics Data System (ADS)

    Rüter, C. E.; Suntsov, S.; Kip, D.; Stone, G.; Dierolf, V.; Hu, H.; Sohler, W.

    2014-03-01

    Lithium-niobate-on-insulator (LNOI) is a new material platform for integrated optics allowing for small bending radii, high intensities and superior electro-optical and nonlinear properties. Ridge waveguides of different width are fabricated on pure and Er-doped LNOI substrates using diamond-blade dicing, resulting in smooth side walls with lower roughness when compared to dry etching techniques. Propagation losses for polarized modes are measured by the Fabry-Perot method using a fiber coupling setup and a tunable laser at 1.5 μm. Loss values as low as ~1.4dBcm-1 were obtained for quasi-TM (qTM) modes, while losses for qTE modes are slightly higher. Characterization of Er:LNOI ridges is performed using Raman and fluorescence spectroscopy. Spectral scans are obtained using a scanning confocal microscope and a 488nm laser. Besides line broadening that may be attributed to internal strain in the bonded layer and implantation induced defects, analysis of Raman spectra shows no significant difference between waveguide and bulk material. However, Er emission of 2H11/2 and 4S3/2 to 4I15/2 contains small spatial differences across the layer thickness when compared to Er-doped bulk samples. While Raman intensity has a linear relationship with pump power, the intensity of the Er emission starts saturating already at pump levels of a few mW. To investigate fluorescence of the 4I13/2-4I15/2 transition inside the diced ridges, a fiber-coupled laser with wavelength 980nm is used for pumping. The emission is broadened and maxima are shifted to longer wavelengths, which may be attributed to defects induced by implantation, strain induced by the bonded LN-SiO2 interface, and re-absorption of fluorescence light.

  7. Voltage-induced waveguides in lithium niobate films on silicon substrates.

    PubMed

    Chauvet, M; Thoa, P; Bassignot, F

    2017-03-15

    Electrically tunable channel waveguides have been fabricated by domain inversion of a LiNbO3 thin film bonded to a silicon wafer. The electro-optic effect is used to induce the waveguides and to alter its guiding properties. A low amplitude electric signal can tune the voltage-induced structure from an efficient waveguide to an antiguide giving a waveguide transmission that varies over more than 25 dB. The frequency response of the components is given.

  8. Clean waveguides in lithium niobate thin film formed by He ion implantation

    NASA Astrophysics Data System (ADS)

    Zhang, Shao-Mei; Jiang, Yun-Peng; Jiao, Yang

    2017-08-01

    We report on the fabrication of channel waveguides by He ion implantation in a single-crystal LiNbO3 film bonded to a SiO2/LiNbO3 substrate. The planar waveguides were also formed under the same conditions to show the refractive index changes and the thermal annealing properties of ion-implanted LiNbO3 thin film. Using a moderate implantation energy, the formed channel waveguides were clean because He ions passed through the LiNbO3 thin film and deposited into the SiO2 layer. The optical propagation properties of channel waveguides were measured using an end-face coupling method, and the theoretical results were simultaneously calculated for comparison. The mode sizes and end-face reflectivities of channel waveguides with different widths were numerically calculated. The propagation losses were also estimated at approximately 12.2 and 14.3 dB/cm for 7 μm- and 5 μm-wide waveguides, respectively, by the Fabry-Perot method.

  9. Femtosecond laser-written lithium niobate waveguide laser operating at 1085 nm

    NASA Astrophysics Data System (ADS)

    Tan, Yang; de Aldana, Javier R. Vázquez; Chen, Feng

    2014-10-01

    We report on the channel waveguide lasers at 1085 nm in femtosecond laser written Type II waveguides in an Nd:MgO:LiNbO3 crystal. The waveguide was constructed in a typical dual-line approach. In the geometry, we found that four vicinal regions of the track pair could guide light propagation. In addition, these guiding cores support polarization-dependent-guided modes. The propagation losses of the waveguides were measured to be as low as 1 dB/cm. Under an optical pump at 808 nm, the continuous-wave waveguide lasing at 1085 nm was generated, reaching a slope efficiency of 27% and maximum output power of 8 mW. The lasing threshold was 71 mW. Our results show that with the femtosecond laser written Nd:MgO:LiNbO3 waveguide as the miniature light source, it was possible to construct all-LiNbO3-based integrated devices for diverse photonic applications.

  10. Titanium Indiffusion Proton Exchange (tipe) Waveguide Lenses in Lithium-Niobate and Their Applications.

    NASA Astrophysics Data System (ADS)

    Zang, De-Yu.

    1988-06-01

    We have developed a new type of waveguide lenses in LiNbO_3, the Titanium-Indiffusion Proton-Exchanged (TIPE) lens which has many desirable performance characteristics including near diffraction focal spot size, short focal length, large numerical aperture, large angular field of view, and low insertion loss. Since only a single -mask photolithographic process is required in fabrication of the TIPE waveguide lenses, it is extremely simple and flexible for their design and fabrication. The process also facilitates accurate optical alignment with other components in the waveguide substrate. Specifically, large linear microlens arrays that consist of very very short focal length lenses and a single large-aperture integrating lens can be formed simultaneously using the TIPE technique with very accurate optical alignment. A number of acoustooptic (AO) and electrooptic (EO) Bragg modulators have been fabricated together with the TIPE lenses on channel-planar composite waveguides with applications to information processing and computing. Specifically, matrix-vector multiplication has been successfully carried out using the integrated AO Bragg modulator modules and the EO single-grating array modulator modules. In addition, the EO herringbone-grating array modulator modules were built to carry out matrix -matrix multiplication. Finally, multichannel integrated optic modules that utilize arrays of EO herringbone-grating modulators were constructed to perform programmable correlations of binary sequences. These multichannel integrated optic modules represent the highest degree of integration that has been accomplished in the LiNbO_3 substrate thus far. A series of correlation waveforms between two binary sequences have been obtained. These correlation waveforms are shown to be in excellent agreement with the theoretical calculations.

  11. Fabrication and characterization of Titanium Indiffused Proton Exchanged (TIPE) waveguides in lithium niobate

    NASA Astrophysics Data System (ADS)

    De Micheli, M.; Botineau, J.; Sibillot, P.; Ostrowsky, D. B.; Papuchon, M.

    1982-06-01

    We report the fabrication and characterization of optical waveguides realized in LiNbO 3 by a combined titanium indiffusion proton exchange (TIPE) process. These guides provide several unique advantages which include permitting tailorong of guide birefringence, realizing proton exchanged Y-cut plates of good optical quality, and the realization of imbedded TM guides due to a lowering of no caused by proton exchange.

  12. Femtosecond writing of near-surface waveguides in lithium niobate for low-loss electro-optical modulators of broadband emission

    NASA Astrophysics Data System (ADS)

    Bukharin, Mikhail A.; Skryabin, Nikolay N.; Khudyakov, Dmitriy V.; Vartapetov, Sergey K.

    2016-05-01

    In the investigation we demonstrated technique of direct femtosecond laser writing of tracks with induced refractive index at record low depth under surface of lithium niobate (3-15 μm). It was shown that with the help of proposed technique one can be written claddings of near surface optical waveguides that plays a key role in fabrication of fast electro-optical modulators with low operating voltage. Fundamental problem resolved in the investigation consists in suppression of negative factors impeding femtosecond inscription of waveguides at low depths. To prevent optical breakdown of crystal surface we used high numerical aperture objectives for focusing of light. It was shown, that advanced heat accumulation regime of femtosecond inscription is inapplicable for writing of near-surface waveguides, and near the surface waveguides should be written in non-thermal regime in contrast to widespread femtosecond writing at depths of tens micrometers. Inscribed waveguides were examined for optical losses and polarization properties. It was experimentally shown, that femtosecond written near surface waveguides have such advantages over widely used proton exchanged and Ti-diffusion waveguides as lower optical losses (down to 0.3 dB/cm) and maintaining of all polarization states of propagation light, which is crucial for development of electro-optical modulators for broadband and ultrashort laser emission. Novelty of the results consists in technique of femtosecond inscription of waveguides at record low depths under the surface of crystals. As compared to previous investigations in the field (structures at depths near 50 um with buried electrodes), the obtained waveguides could be used with simple closely adjacent on-surface electrodes.

  13. Possibility of tailoring ne vs. cLi relations in lithium niobate optical waveguides for sensors applications

    NASA Astrophysics Data System (ADS)

    Spirkova-Hradilova, Jarmila; Nekvindova, Pavla; Vacik, Jiri; Cervena, Jarmila; Schroefel, Josef

    1999-12-01

    We present results of our study of concentration profiles of lithium (cLi) in annealed proton exchanged (APE) waveguiding layers as measured by the neutron depth profiling method. This non-destructive method is based on the 6Li(n,(alpha) )3H reaction induced by thermal neutrons and allowed easy monitoring of cLi profiles in a large number of samples fabricated under various fabrication conditions. Our systematic study revealed that there was no linear relationship which unambiguously attributed (Delta) ne to (Delta) cLi, on contrast with up to now generally accepted opinion. Every particular waveguide has very similar mirror-shaped ne as well as cLi depth profiles, but, generally, all the waveguides can not be characterized with the same ne vs. cLi relationship. The most important fabrication step has appeared to be the post-exchange annealing, during which lithium atoms are transported towards the sample surfaces. The annealing regime pre-destined not only the depth distribution of lithium atoms, but as a consequence of it, also other properties of the waveguiding region. We have formulated ne vs. cLi semi-empirical relationship and listed a set of case-dependent empirical constants for our fabrication system. That allows us to fabricate the APE waveguides with a priori given properties for a wide range of special applications.

  14. Q-factor enhancement of integrated lithium-niobate-on-insulator ridge waveguide whispering-gallery-mode resonators by surface polishing

    NASA Astrophysics Data System (ADS)

    Wolf, Richard; Breunig, Ingo; Zappe, Hans; Buse, Karsten

    2017-02-01

    Whispering-gallery resonators (WGRs) are most promising for nonlinear-optical frequency-conversion due to their intensity enhancement by small mode volumes and high Q-factors. This has been shown frequently by millimeter-sized diamond-blade cut and polished bulk WGRs. For reproducible batch fabrication, however, the integration of WGRs into lithium-niobate-on-insulator (LNOI) substrates became of great interest. Here we report on integrated WGRs made by batch processes like lithography and reactive-ion etching. Since the Q-factor of integrated WGRs is limited by scattering losses, we focused on developing a polishing process for the waveguide sidewalls that allowed us to enhance the unloaded Q-factors already to more than 106 with room for further improvements. Furthermore we employ a coupling scheme with two waveguide chips, one comprising a linear coupling waveguide and one with the integrated WGR. By adjusting the distance between the coupling waveguide and the WGR, we can reproducibly and stably tune the coupling-efficiency between 0 and 95 %.

  15. Simultaneous subchannel data updating for multiple channels of 16-quadrature amplitude modulation signals using a single periodically poled lithium niobate waveguide.

    PubMed

    Huang, Hao; Yang, Jeng-Yuan; Wu, Xiaoxia; Khaleghi, Salman; Ziyadi, Morteza; Tur, Moshe; Langrock, Carsten; Fejer, Martin M; Paraschis, Loukas; Willner, Alan E

    2012-11-01

    Subchannel data updating of high-order modulation format signals using cascaded sum- and difference-frequency generation in a single periodically poled lithium niobate waveguide is demonstrated. One quadrature phase-shift-keying subchannel of a 16-quadrature amplitude modulation (QAM) signal at 40 Gbit/s is successfully updated, with an optical signal-to-noise ratio (OSNR) penalty of ~2 dB for return-to-zero and ~4 dB for non-return-to-zero at a bit-error rate (BER) of 2×10(-3). Simultaneous processing of four wavelength-multiplexed 16-QAM signals with an average OSNR penalty of 4.5 dB at a BER of 2×10(-3) is also demonstrated.

  16. Optical storage in lithium niobate

    NASA Technical Reports Server (NTRS)

    Alphonse, G. A.

    1976-01-01

    Holographic storage and retrieval using photorefractive media (electro-optic ferroelectric materials), particularly iron-doped lithium niobate with its enhanced sensitivity, are discussed. Refractive index changes induced by exposure to light render the materials useful for read-write memories and read-write memory simulation. Resolution, dark storage time, write and erase times, reversibility, and noise levels of the materials are examined. The laser source, deflection system, hololens, page composer, and detector array of the holographic memory system are described. High SNR and two orders of magnitude improvement in speed are reported over earlier experimental prototypes, but the system is still too slow to meet practical needs.

  17. Lithium Niobate Reactive Ion Etching

    DTIC Science & Technology

    2000-07-01

    sputter method. The coated substrates were then patterned using a photolithographic mask with AZP 4620 photoresist. The NiCr layer was sputter etched to...create the NiCr RIE mask and the photoresist residual removed. Sputter etch was the chosen technology to pattern the NiCr for two main reasons; - An...2. Experimental Description 2.1 Preparation of Lithium Niobate Samples The LiNbO3 substrates were coated with a 3000 A layer of NiCr using the RF

  18. Stoichiometric Lithium Niobate (SLN) Based Linearized Electro-Optic (EO) Modulator

    DTIC Science & Technology

    2006-01-01

    AFRL-SN-RS-TR-2006-15 Final Technical Report January 2006 STOICHIOMETRIC LITHIUM NIOBATE (SLN) BASED LINEARIZED ELECTRO - OPTIC (EO...LITHIUM NIOBATE (SLN) BASED LINEARIZED ELECTRO - OPTIC (EO) MODULATOR 6. AUTHOR(S) Dr Stuart Kingsley, Dr Sri Sriram 5. FUNDING NUMBERS C...SUBJECT TERMS electro - optic modulator, linearization, directional coupler, variable coupling, optical waveguide, Mach-Zehnder, photonic link, lithium

  19. Micro- and nano-domain engineering in lithium niobate

    SciTech Connect

    Shur, V. Ya.; Akhmatkhanov, A. R.; Baturin, I. S.

    2015-12-15

    The physical basis of the domain engineering in ferroelectrics and its application to lithium niobate crystals were reviewed. The unified kinetic approach to the domain structure evolution in electric field was formulated and its validity for understanding the variety of observed domain evolution scenarios was demonstrated. The kinetics and statics of the domain structure in the crystals of lithium niobate family including congruent, stoichiometric, and MgO doped ones have been discussed. The main stages of the periodical poling process and related problems have been pointed out. The basic poling techniques applied for creation of the periodical domain structures in bulk crystals and waveguides were compared. The recent applications of the periodically poled lithium niobate for light frequency conversion using second harmonic generation and optical parametric oscillation, excitation of the surface acoustic waves, and generation of terahertz radiation have been discussed. The special attention has been paid for achievements in fabrication of high-power optical parametric oscillation and integrated optical devices with periodically poled lithium niobate. The future trends in periodical poling and development of the nanodomain engineering which will allow to create the nanoscale domain patterns necessary for utilization of the new nonlinear interactions were reviewed.

  20. Anomalous angular dispersion in lithium niobate one-dimensional waveguide array in the near-infrared wavelength range

    NASA Astrophysics Data System (ADS)

    Apetrei, Alin Marian; Rambu, Alicia Petronela; Minot, Christophe; Moison, Jean-Marie; Belabas, Nadia; Tascu, Sorin

    2017-02-01

    Knowing the dispersion properties of a device is important in many applications (e.g., wavelength separation). For an isolated waveguide, besides the material dispersion, one must consider the waveguide influence as well, through waveguide dispersion and mode dispersion. For a waveguide array, one must consider the influence of evanescent coupling between adjacent waveguides as well. We investigate by the Finite Element Method the angular dispersion of a LiNbO3 waveguide array using two techniques. The first one assumes the Coupled Mode Theory in a 2-waveguide system. The other one uses the actual diffraction curve determined in a 7-waveguide system. In both approaches, we find that by decreasing the array period, one passes from normal angular dispersion by an achromatic point to anomalous angular dispersion. We then illustrate the wavelength separation by the waveguide array by doing Runge-Kutta light propagation simulations. As all the values of parameters are technologically feasible, this opens new possibilities for optical data processing, such as WDM and dispersion compensation.

  1. Reduced Dimensionality Lithium Niobate Microsystems

    SciTech Connect

    Eichenfield, Matt

    2017-01-01

    The following report describes work performed under the LDRD program at Sandia National Laboratories October 2014 and September 2016. The work presented demonstrates the ability of Sandia Labs to develop state-of-the-art photonic devices based on thin film lithium niobate (LiNbO3 ). Section 1 provides an introduction to integrated LiNbO3 devices and motivation for developing thin film nonlinear optical systems. Section 2 describes the design, fabrication, and photonic performance of thin film optical microdisks fabricated from bulk LiNbO3 using a bulk implantation method developed at Sandia. Sections 3 and 4 describe the development of similar thin film LiNbO3 structures fabricated from LiNbO3 on insulator (LNOI) substrates and our demonstration of optical frequency conversion with state-of-the-art efficiency. Finally, Section 5 describes similar microdisk resonators fabricated from LNOI wafers with a buried metal layer, in which we demonstrate electro-optic modulation.

  2. Triboelectric Nanogenerator Using Lithium Niobate Thin Film

    NASA Astrophysics Data System (ADS)

    Geng, Juan; Zhang, Xinzheng; Kong, Yongfa; Xu, Jingjun

    2017-06-01

    We present a triboelectric nanogenerator (TENG) using a lithium niobate thin film, as one of the triboelectric pairs which was grown on a silicon substrate by laser molecule beam epitaxy (LMBE). The designed TENG has the advantages of simple structure, easy fabrication, small size (1.1*1.0*0.15 cm3). An open-circuit voltage of 136 V and a short-circuit current of 8.40 μA have been achieved. The maximum output power is 307.5μW under the load resistance of 10MΩ. This is the first time to use lithium niobate thin film as one of the friction pair, which may make it possible to expand the application of triboelectric nanogenerator to optical field.

  3. Er + medium energy ion implantation into lithium niobate

    NASA Astrophysics Data System (ADS)

    Svecova, B.; Nekvindova, P.; Mackova, A.; Oswald, J.; Vacik, J.; Grötzschel, R.; Spirkova, J.

    2009-05-01

    Erbium-doped lithium niobate (Er:LiNbO3) is a prospective photonics component, operating at 1.5 μm, which could find its use chiefly as an optical amplifier or waveguide laser. In this study, we have focused on the properties of the optically active Er:LiNbO3 layers, which are fabricated by medium energy ion implantation under various experimental conditions. Erbium ions were implanted at energies of 330 and 500 keV with fluences of 1.0 × 1015, 2.5 × 1015 and 1.0 × 1016 cm-2 into LiNbO3 single-crystalline cuts of various orientations. The as-implanted samples were annealed in air at 350 °C for 5 h. The depth distribution and diffusion profiles of the implanted Er were measured by Rutherford Backscattering Spectroscopy (RBS) using 2 MeV He+ ions. The projected range RP and projected range straggling ΔRP were calculated employing the SRIM code. The damage distribution and structural changes were described using the RBS/channelling method. Changes of the lithium concentration depth distribution were studied by Neutron Depth Profiling (NDP). The photoluminescence spectra of the samples were measured to determine whether the emission was in the desired region of 1.5 μm. The obtained data made it possible to reveal the relations between the structural changes of erbium-implanted lithium niobate and its luminescence properties important for photonics applications.

  4. Fundamental investigations of ultrashort-pulse micromachining of different types of crystalline lithium niobate

    NASA Astrophysics Data System (ADS)

    Stolze, M.; Herrmann, T.; L'huillier, J. A.

    2016-03-01

    Characteristics by laser micromachining of congruent, stoichiometric and doped lithium niobate by using ultrashort laser pulses with different wavelengths from ultraviolet up to infrared were investigated. The ablation thresholds were determined in dependence of c+-side and accordingly c--side. The strong impact of crystal orientation by micromachining lithium niobate will be additionally shown by the use of a high pulse repetition rate of 1000 kHz. Furthermore, we demonstrate the advantage of processing smooth ridges with high-repetition UV picosecond laser-pulses in combination of post-processing thermal annealing and a low-loss ridge waveguide in congruent LiNbO3 will be demonstrated.

  5. Optimal design of DC-based polarization beam splitter in lithium niobate on insulator

    NASA Astrophysics Data System (ADS)

    Gong, Zisu; Yin, Rui; Ji, Wei; Wang, Junbao; Wu, Chonghao; Li, Xiao; Zhang, Shicheng

    2017-08-01

    We propose a DC-based polarization beam splitter (PBS) in lithium niobate on insulator (LNOI). Utilizing the high birefringence property of Lithium Niobate (LiNbO3, LN), the device is achieved by simple structure in a short length. With the use of beam propagation method (BPM), the simulation results show that the device has a good performance for the separation of TE and TM polarizations with a high extinction ratio (about 35 dB). The simulated fabrication tolerance for the variation of the waveguide width is about 100 nm and the bandwidth is about 65 nm when the extinction ratio is higher than 10 dB.

  6. Efficient second harmonic generation in χ(2) profile reconfigured lithium niobate thin film

    NASA Astrophysics Data System (ADS)

    Cai, Lutong; Wang, Yiwen; Hu, Hui

    2017-03-01

    Second harmonic wave was efficiently generated in proton exchanged lithium niobate thin film channel waveguides. Modal dispersion phase matching was achieved between two guided modes at pump and second-harmonic wavelengths with the same polarization, enabling using the largest second-order nonlinear component d33. The χ(2) profile in the lithium niobate thin film was reconfigured by proton exchange, leading to significantly enhanced modal overlap integral between the interacting modes. Normalized conversion efficiency up to 48% W-1 cm-2 was achieved in experiments.

  7. Optical properties of lithium niobate single crystals

    NASA Astrophysics Data System (ADS)

    Palatnikov, M. N.; Sidorov, N. V.; Biryukova, I. V.; Kalinnikov, V. T.; Bormanis, K.

    2005-01-01

    Studies of thermal and -irradiation effects on the optical properties in congruous lithium niobate single crystals containing Y, Mg, Gd, B, and Zn dopants including samples with double dopants Y, Mg and Gd, Mg are reported. Formation of defects at irradiation and thermal treatment of the samples is explored by electron absorption spectra. Considerable increase of absorption with the dose of -radiation is observed at 500 nm. The changes of absorption examined under different conditions are explained by creation and destruction of Nb4+ defects.

  8. Polarization entangled cluster state generation in a lithium niobate chip

    NASA Astrophysics Data System (ADS)

    Szep, Attila; Kim, Richard; Shin, Eunsung; Fanto, Michael L.; Osman, Joseph; Alsing, Paul M.

    2016-10-01

    We present a design of a quantum information processing C-phase (Controlled-phase) gate applicable for generating cluster states that has a form of integrated photonic circuits assembled with cascaded directional couplers on a Ti in-diffused Lithium Niobate (Ti-LN) platform where directional couplers as the integrated optical analogue of bulk beam splitters are used as fundamental building blocks. Based on experimentally optimized fabrication parameters of Ti-LN optical waveguides operating at an 810nm wavelength, an integrated Ti-LN quantum C-phase gate is designed and simulated. Our proposed C-phase gate consists of three tunable directional couplers cascaded together with having different weighted switching ratios for providing a tool of routing vertically- and horizontally-polarized photons independently. Its operation mechanism relies on selectively controlling the optical coupling of orthogonally polarized modes via the change in the index of refraction, and its operation is confirmed by the BPM simulation.

  9. Grating coupler on single-crystal lithium niobate thin film

    NASA Astrophysics Data System (ADS)

    Chen, Zhihua; Wang, Yiwen; Jiang, Yunpeng; Kong, Ruirui; Hu, Hui

    2017-10-01

    The grating coupler on single-crystal lithium niobate thin film (lithium niobate on insulator, LNOI) was designed. A bottom reflector was added in the LNOI material to improve the coupling efficiency. The grating structure was optimized by FDTD method. The material parameters such as layer thickness of lithium niobate thin film, SiO2 thickness were discussed with respect to the coupling efficiency, and the tolerances of grating period, etch depth, groove width and fiber position were also studied systematically. The simulated maximum coupling efficiency from a grating coupler with (without) bottom reflector to a single-mode fiber is about 78% (40%) in z-cut LNOI for TE polarization.

  10. Study of multiple hologram recording in lithium niobate

    NASA Technical Reports Server (NTRS)

    Gaylord, T. K.; Callen, W. R.

    1976-01-01

    The results of a number of theoretical and experimental studies relating to multiple hologram recording in lithium niobate are reported. The analysis of holographic gratings stored in lithium niobate has been extended to cover a more realistic range of physical situations. A new successful dynamic (feedback) theory for describing recording, nondestructive reading, erasure, enhancement, and angular sensitivity has been developed. In addition, the possible architectures of mass data storage systems have been studied.

  11. Pyroelectric generation of 2D spatial soliton sets in a bulk of lithium niobate crystal

    NASA Astrophysics Data System (ADS)

    Ryabchenok, V.; Shandarov, V.; Perin, A.

    2017-06-01

    The generation of two-dimensional bright spatial soliton sets in lithium niobate sample has been experimentally demonstrated at light wavelength of 532 nm, contribution of pyroelectric effect into nonlinear optical response of the crystal, and spatial modulation of one-dimensional beam along direction normal to the crystal optical axis. Diameters of soliton beams and channel waveguides formed within the crystal bulk by these solitons are near to 20 μm at light polarization corresponding to extraordinary wave of the crystal.

  12. Lithium niobate-on-insulator (LNOI): status and perspectives

    NASA Astrophysics Data System (ADS)

    Hu, Hui; Yang, Jin; Gui, Li; Sohler, Wolfgang

    2012-06-01

    As optical components continue to replace electronics in ultrafast signal processing applications, a growing interest in further miniaturization and integration of photonic devices on a single chip is observed. Therefore, optical waveguides of high refractive index contrast of core and cladding materials are developed since a couple of years. They can have a very small cross section and also bending radius, enabling the development of ultra-compact photonic integrated devices and circuits. Silicon-On-Insulator (SOI) waveguides ("photonic wires") and devices are the most prominent examples. A corresponding technology for Lithium Niobate-On-Insulator (LNOI) waveguides is still in its infancy, though LN offers - in contrast to SOI - excellent electro-optic, acousto-optic, and nonlinear optical properties. Moreover, it can be easily doped with rare-earth ions to get a laser active material. Therefore, LNOI photonic wires will enable the development of a wide range of extremely compact, active integrated devices, including electro-optical modulators, tunable filters, nonlinear (periodically poled) wavelength converters, and amplifiers and lasers of different types. The state-of-the-art of LNOI films as platform for high-density integrated optics is reviewed. Using a full-wafer technology (3" diameter), sub-micrometer thin LN films are obtained by high-dose He+ ion implantations, crystal-bonding to a low-index substrate (preferably SiO2) and cleaving by a special annealing step ("ion-beam-slicing"). Various LNOI structures, also combined with metallic layers, are presented. Based on such platforms, photonic wires and micro-photonic devices are developed using different micro- and nano-structuring techniques. To be specific, the fabrication and characterization of LNOI photonic wires with cross-section < 1 μm2, and periodically poled LNOI photonic wires for second harmonic generation are reported in detail.

  13. Two-Color Holography in Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Macfarlane, R.; Guenther, H.; Furukawa, Y.; Kitamura, L.

    The development of a really satisfactory recording material for holographic data storage applications remains perhaps the most important barrier to practical implementation of the technology [1]. As discussed in the chapter entitled "Media Requirement for Digital Holographic Data Storage," the ideal material must simultaneously possess many properties such as good sensitivity, large dynamic range, long data retention times and excellent optical quality. In addition the material must be stable under repeated read cycles. This is easier to achieve in write-once-read-many (WORM) storage systems, since the material can be permanently deactivated after the writing process. In this application, irreversible chemical modification such as photochromism, photopolyrnerization etc. can be used. For reversible media the situtation is more difficult because the "fixing" process must be reversible, allowing rewriting immediately after an earlier recording or reading step. The requirement of reversibility often makes it more difficult to achieve long dark data retention times. Three main schemes for providing nondestructive readout in reversible photorefractive media have been proposed. The first was thermal fixing in lithium niobate [2,3], where a copy of the stored index gratings is made by thermally activating proton diffusion, which creates an optically stable complementary proton grating.

  14. Lithium niobate ultrasonic transducer design for Enhanced Oil Recovery.

    PubMed

    Wang, Zhenjun; Xu, Yuanming; Gu, Yuting

    2015-11-01

    Due to the strong piezoelectric effect possessed by lithium niobate, a new idea that uses lithium niobate to design high-power ultrasonic transducer for Enhanced Oil Recovery technology is proposed. The purpose of this paper is to lay the foundation for the further research and development of high-power ultrasonic oil production technique. The main contents of this paper are as follows: firstly, structure design technique and application of a new high-power ultrasonic transducer are introduced; secondly, the experiment for reducing the viscosity of super heavy oil by this transducer is done, the optimum ultrasonic parameters for reducing the viscosity of super heavy oil are given. Experimental results show that heavy large molecules in super heavy oil can be cracked into light hydrocarbon substances under strong cavitation effect caused by high-intensity ultrasonic wave. Experiment proves that it is indeed feasible to design high-power ultrasonic transducer for ultrasonic oil production technology using lithium niobate.

  15. Precise, reproducible nano-domain engineering in lithium niobate crystals

    SciTech Connect

    Boes, Andreas Sivan, Vijay; Ren, Guanghui; Yudistira, Didit; Mitchell, Arnan; Mailis, Sakellaris; Soergel, Elisabeth

    2015-07-13

    We present a technique for domain engineering the surface of lithium niobate crystals with features as small as 100 nm. A film of chromium (Cr) is deposited on the lithium niobate surface and patterned using electron beam lithography and lift-off and then irradiated with a wide diameter beam of intense visible laser light. The regions patterned with chromium are domain inverted while the uncoated regions are not affected by the irradiation. With the ability to realize nanoscale surface domains, this technique could offer an avenue for fabrication of nano-photonic and phononic devices.

  16. Zr doping on lithium niobate crystals: Raman spectroscopy and chemometrics

    NASA Astrophysics Data System (ADS)

    Kokanyan, Ninel; Chapron, David; Kokanyan, Edvard; Fontana, Marc D.

    2017-03-01

    Raman measurements were investigated on Zr-doped lithium niobate LiNbO3 crystals with different concentrations. Spectra were treated by fitting procedure and principal component analysis which both provide results consistent with each other. The concentration dependence of the frequency on the main low-frequency optical phonons provides an insight of site incorporation of Zr ions in the host lattice. The threshold concentration of about 2% is evidenced, confirming the interest of Zr doping as an alternative to Mg doping for the reduction of the optical damage in lithium niobate.

  17. Ferroelectric domain engineering and micro-structuring of lithium niobate

    NASA Astrophysics Data System (ADS)

    Mailis, Sakellaris

    2010-11-01

    This paper discusses a number of recently developed all optical and optically assisted methods for ferroelectric domain engineering in lithium niobate and their impact on the micro-structuring of this optical ferroelectric crystal. Optical radiation is used to change the response of lithium niobate crystals to externally applied electric field encouraging or inhibiting ferroelectric domain inversion in a simultaneous or latent manner. Optically assisted poling processes have the advantage of producing ferroelectric domains with arbitrary shapes free from crystal symmetry restrictions which is very important for fabricating surface micro/nano-structures in this material.

  18. Study of multiple hologram recording in lithium niobate

    NASA Technical Reports Server (NTRS)

    Gaylord, T. K.; Callen, W. R.

    1974-01-01

    The results of detailed experimental and theoretical considerations relating to multiple hologram recording in lithium niobate are reported. The following problem areas are identified and discussed: (1) the angular selectivity of the stored holograms, (2) interference effects due to the crystal surfaces, (3) beam divergence effects, (4) material recording sensitivity, and (5) scattered light from material inhomogeneities.

  19. Nanoscale surface and subsurface defects induced in lithium niobate by a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Stach, Eric A.; Radmilovic, Velimir; Deshpande, Devesh; Malshe, Ajay; Alexander, Dennis; Doerr, David

    2003-11-01

    In this letter, electron and ion microscopy techniques have been used to characterize the changes that result when single crystals of lithium niobate are processed using a focused femtosecond laser. The prevailing observation is that of competing processes—ablation and partial redeposition, thermal shock, and extreme quenching, as well as effects associated with shock wave propagation, resulting in both amorphization and heavily defective regions at the focal point of the laser pulse. The observed microstructural defects have a direct implication in optical memory or waveguide writing, where the goal is to realize consistent structural features with uniform optical properties.

  20. Fabrication of low-loss ridge waveguides in z-cut lithium niobate by combination of ion implantation and UV picosecond laser micromachining

    NASA Astrophysics Data System (ADS)

    Stolze, M.; Herrmann, T.; L'huillier, J. A.

    2016-03-01

    Ridge waveguides in ferroelectric materials like LiNbO3 attended great interest for highly efficient integrated optical devices, for instance, electro-optic modulators, frequency converters and ring resonators. The main challenges are the realization of high index barrier towards the substrate and the processing of smooth ridges for minimized scattering losses. For fabricating ridges a variety of techniques, like chemical and wet etching as well as optical grade dicing, have been investigated in detail. Among them, laser micromachining offers a versatile and flexible processing technology, but up to now only a limited side wall roughness has been achieved by this technique. Here we report on laser micromachining of smooth ridges for low-loss optical waveguides in LiNbO3. The ridges with a top width of 7 µm were fabricated in z-cut LiNbO3 by a combination of UV picosecond micromachining and thermal annealing. The laser processing parameters show a strong influence on the achievable sidewall roughness of the ridges and were systematically investigated and optimized. Finally, the surface quality is further improved by an optimized thermal post-processing. The roughness of the ridges were analysed with confocal microscopy and the scattering losses were measured at an optical characterization wavelength of 632.8 nm by using the end-fire coupling method. In these investigations the index barrier was formed by multi-energy low dose oxygen ion implantation technology in a depth of 2.7 μm. With optimized laser processing parameters and thermal post-processing a scattering loss as low as 0.1 dB/cm has been demonstrated.

  1. RBS measurement of depth profiles of erbium incorporated into lithium niobate for optical amplifier applications

    NASA Astrophysics Data System (ADS)

    Peřina, Vratislav; Vacík, Jiří; Hnatovicz, Vladimír.; Červená, Jarmila; Kolářová, Pavla; Špirková-Hradilová, Jarmila; Schröfel, Josef

    1998-04-01

    Rutherford Backscattering Spectrometry (RBS) was used for the determination of Er 3+ concentration profiles in locally doped lithium niobate. The doped layers are the basic substrates for the fabrication of optical waveguiding structures which may be utilized as planar optical amplifiers and waveguiding lasers making use of the 4I 13/2 → 4I 15/2 transition in Er 3+, which falls into the third low loss telecommunication window (1.5 μm). We present a new aproach of fabrication of locally doped lithium niobate single crystal wafers. The doping occurs under moderate temperature (˜350°C) from reaction melts containing ca. 10 wt% of erbium nitrate. The erbium content in particular cuts varies dramatically between ca. 3 at.% in the Y- and Z-cut up to 20 at.% in the X-cuts. Erbium ions are localized in a 50 nm thick layer, but they can be diffused deeper into the substrate by subsequent annealing at 350°C. The Er concentrations of the samples doped at moderated temperature are compared with the Er concentrations of the samples doped by a standard high-temperature diffusion (>1000°C) from evaporated metal layers. To utilize the Er doped substrates in integrated optic circuits high quality waveguides must be subsequently fabricated. For that we used the Annealed Proton Exchange (APE) method with adipic acid. For the actual fabrication of the waveguides the following order of operation should be kept: the erbium doping should be done before the APE because the substantially changed structure of APE layers prevents the doping process. The APE process is checked by measurements of lithium depth profiles by Neutron Depth Profiling (NDP).

  2. Chip-scale cavity optomechanics in lithium niobate

    NASA Astrophysics Data System (ADS)

    Jiang, Wei C.; Lin, Qiang

    2016-11-01

    We develop a chip-scale cavity optomechanical system in single-crystal lithium niobate that exhibits high optical quality factors and a large frequency-quality product as high as 3.6 × 1012 Hz at room temperature and atmosphere. The excellent optical and mechanical properties together with the strong optomechanical coupling allow us to efficiently excite the coherent regenerative optomechanical oscillation operating at 375 MHz with a threshold power of 174 μW in the air. The demonstrated lithium niobate optomechanical device enables great potential for achieving electro-optic-mechanical hybrid systems for broad applications in sensing, metrology, and quantum physics.

  3. Chip-scale cavity optomechanics in lithium niobate

    PubMed Central

    Jiang, Wei C.; Lin, Qiang

    2016-01-01

    We develop a chip-scale cavity optomechanical system in single-crystal lithium niobate that exhibits high optical quality factors and a large frequency-quality product as high as 3.6 × 1012 Hz at room temperature and atmosphere. The excellent optical and mechanical properties together with the strong optomechanical coupling allow us to efficiently excite the coherent regenerative optomechanical oscillation operating at 375 MHz with a threshold power of 174 μW in the air. The demonstrated lithium niobate optomechanical device enables great potential for achieving electro-optic-mechanical hybrid systems for broad applications in sensing, metrology, and quantum physics. PMID:27841301

  4. Periodic domain inversion in x-cut single-crystal lithium niobate thin film

    NASA Astrophysics Data System (ADS)

    Mackwitz, P.; Rüsing, M.; Berth, G.; Widhalm, A.; Müller, K.; Zrenner, A.

    2016-04-01

    We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO2 layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the +z side.

  5. Periodic domain inversion in x-cut single-crystal lithium niobate thin film

    SciTech Connect

    Mackwitz, P. Rüsing, M.; Berth, G.; Zrenner, A.; Widhalm, A.; Müller, K.

    2016-04-11

    We report the fabrication of periodically poled domain patterns in x-cut lithium niobate thin-film. Here, thin films on insulator have drawn particular attention due to their intrinsic waveguiding properties offering high mode confinement and smaller devices compared to in-diffused waveguides in bulk material. In contrast to z-cut thin film lithium niobate, the x-cut geometry does not require back electrodes for poling. Further, the x-cut geometry grants direct access to the largest nonlinear and electro-optical tensor element, which overall promises smaller devices. The domain inversion was realized via electric field poling utilizing deposited aluminum top electrodes on a stack of LN thin film/SiO{sub 2} layer/Bulk LN, which were patterned by optical lithography. The periodic domain inversion was verified by non-invasive confocal second harmonic microscopy. Our results show domain patterns in accordance to the electrode mask layout. The second harmonic signatures can be interpreted in terms of spatially, overlapping domain filaments which start their growth on the +z side.

  6. Heterogeneous microring and Mach-Zehnder modulators based on lithium niobate and chalcogenide glasses on silicon

    SciTech Connect

    Rao, Ashutosh; Patil, Aniket; Chiles, Jeff; Malinowski, Marcin; Novak, Spencer; Richardson, Kathleen; Rabiei, Payam; Fathpour, Sasan

    2015-08-20

    In this study, thin films of lithium niobate are wafer bonded onto silicon substrates and rib-loaded with a chalcogenide glass, Ge23Sb7S70, to demonstrate strongly confined single-mode submicron waveguides, microring modulators, and Mach-Zehnder modulators in the telecom C band. The 200 μm radii microring modulators present 1.2 dB/cm waveguide propagation loss, 1.2 × 105 quality factor, 0.4 GHz/V tuning rate, and 13 dB extinction ratio. The 6 mm long Mach-Zehnder modulators have a half-wave voltage-length product of 3.8 V.cm and an extinction ratio of 15 dB. The demonstrated work is a key step towards enabling wafer scale dense on-chip integration of high performance lithium niobate electro-optical devices on silicon for short reach optical interconnects and higher order advanced modulation schemes.

  7. Heterogeneous microring and Mach-Zehnder modulators based on lithium niobate and chalcogenide glasses on silicon

    DOE PAGES

    Rao, Ashutosh; Patil, Aniket; Chiles, Jeff; ...

    2015-08-20

    In this study, thin films of lithium niobate are wafer bonded onto silicon substrates and rib-loaded with a chalcogenide glass, Ge23Sb7S70, to demonstrate strongly confined single-mode submicron waveguides, microring modulators, and Mach-Zehnder modulators in the telecom C band. The 200 μm radii microring modulators present 1.2 dB/cm waveguide propagation loss, 1.2 × 105 quality factor, 0.4 GHz/V tuning rate, and 13 dB extinction ratio. The 6 mm long Mach-Zehnder modulators have a half-wave voltage-length product of 3.8 V.cm and an extinction ratio of 15 dB. The demonstrated work is a key step towards enabling wafer scale dense on-chip integration ofmore » high performance lithium niobate electro-optical devices on silicon for short reach optical interconnects and higher order advanced modulation schemes.« less

  8. Incremental holographic recording in lithium niobate with active phase locking.

    PubMed

    Peithmann, K; Wiebrock, A; Buse, K

    1998-12-15

    Angular-multiplexed hologram recording in iron-doped lithium niobate crystals was carried out with near-infrared light. An incremental recording schedule with active phase locking of the light pattern onto the hologram was used. Continuous and reproducible recording of holograms of equal efficiency was achieved, and a hologram multiplexing number, M/#=2 , for a 5-mm-thick crystal was obtained at a 760-nm wavelength of light.

  9. Optical-frequency mixers in periodically poled lithium niobate: Materials, modeling and characterization

    NASA Astrophysics Data System (ADS)

    Roussev, Rostislav Vatchev

    Efficient wavelength conversion is an attractive approach for obtaining coherent radiation in regions of the spectrum where lasers are unavailable or impractical. Optical signal processing in WDM networks, optical-CDMA communications, and quantum communication are examples of applications that can utilize efficient nonlinear frequency conversion at low power levels. Lithium niobate (LN) is a very promising material for the purpose, because it has a mature crystal-growth process, wide transparency range, large second-order nonlinear coefficient, and allows quasi-phasematching via periodic poling (PP). Waveguides enable efficient conversion at low powers and can be formed via reverse proton-exchange. Precise modeling of both the fabrication process and the properties of the resulting waveguides is thus necessary for the demonstration of high-density optical integrated circuits. This dissertation presents a complete fabrication model that accurately predicts the nonlinear diffusion of protons in PPLN as well as the dispersion of the waveguides between 450 and 4000 nm. Using this model, waveguides are fabricated for two experiments: efficient generation of 3--4-mum radiation for spectroscopy via difference frequency generation using two near-IR lasers; and parametric amplification of 1.57-mum seed signal radiation for remote wind sensing using a 1.064-mum pump laser. The waveguides are fabricated in conventional congruent-composition LN. Photorefractive damage (PRD) and green-induced infrared absorption (GRIIRA) limit the generated output power in these devices at room temperature due to the presence of high-intensity visible light. Resistance to PRD and GRIIRA can be achieved by heavy doping with Mg2+, or by using crystals with stoichiometric composition. PRD-resistant, bulk near-stoichiometric lithium niobate (SLN) was fabricated by vapor-transport equilibration (VTE) of originally congruent lithium niobate wafers with light MgO (0.3--1 mol%) doping. Details of the

  10. Liquid crystal deposition on poled, single crystalline lithium niobate

    NASA Astrophysics Data System (ADS)

    Bharath, S. C.; Pimputkar, K. R.; Pronschinske, A. M.; Pearl, T. P.

    2008-01-01

    For the purpose of elucidating the mechanisms for molecular organization at poled ferroelectric surfaces, single crystalline lithium niobate (LN), 'Z-cut' along the (0 0 0 1) plane, has been prepared and characterized and subsequently exposed to liquid crystal molecules. As a model system we chose to study the anchoring of 4- n-octyl-4'-cyanobiphenyl (8CB) to LN. Liquid crystalline films are of interest because of their useful electronic and optical properties as well as chemical sensing attributes. Low-energy electron diffraction (LEED), atomic force microscopy (AFM), surface contact angle measurements (CA), and X-ray photoelectron spectroscopy (XPS) were used to characterize the surface of lithium niobate as well as the nature of 8CB films grown on the surface. Atomically flat LN surfaces were prepared as a support for monolayer thick, 8CB molecular domains. 8CB liquid crystal molecules were deposited by an ambient vaporization technique and the films were analyzed using XPS and CA. Understanding electrostatic anchoring mechanisms and thin film organization for this molecule on uniformly poled surfaces allows for a fuller appreciation of how molecular deposition of other polarizable molecules on periodically poled and patterned poled lithium niobate surfaces would occur.

  11. Integrated opto-microfluidics platforms in lithium niobate crystals for sensing applications

    NASA Astrophysics Data System (ADS)

    Bettella, G.; Pozza, G.; Zaltron, A.; Ciampolillo, M. V.; Argiolas, N.; Sada, C.; Chauvet, M.; Guichardaz, B.

    2015-02-01

    In micro-analytical chemistry and biology applications, droplet microfluidic technology holds great promise for efficient lab-on-chip systems where higher levels of integration of different stages on the same platform is constantly addressed. The possibility of integration of opto-microfluidic functionalities in lithium niobate (LiNbO3) crystals is presented. Microfluidic channels were directly engraved in a LiNbO3 substrate by precision saw cutting, and illuminated by optical waveguides integrated on the same substrate. The morphological characterization of the microfluidic channel and the optical response of the coupled optical waveguide were tested. In particular, the results indicate that the optical properties of the constituents dispersed in the fluid flowing in the microfluidic channel can be monitored in situ, opening to new compact optical sensor prototypes based on droplets generation and optical analysis of the relative constituents.

  12. Hybrid microfiber-lithium-niobate nanowaveguide structures as high-purity heralded single-photon sources

    NASA Astrophysics Data System (ADS)

    Main, Philip; Mosley, Peter J.; Ding, Wei; Zhang, Lijian; Gorbach, Andrey V.

    2016-12-01

    We propose a compact, fiber-integrated architecture for photon-pair generation by parametric downconversion with unprecedented flexibility in the properties of the photons produced. Our approach is based on a thin-film lithium niobate nanowaveguide, evanescently coupled to a tapered silica microfiber. We demonstrate how controllable mode hybridization between the fiber and waveguide yields control over the joint spectrum of the photon pairs. We also investigate how independent engineering of the linear and nonlinear properties of the structure can be achieved through the addition of a tapered, proton-exchanged layer to the waveguide. This allows further refinement of the joint spectrum through custom profiling of the effective nonlinearity, drastically improving the purity of the heralded photons. We give details of a source design capable of generating heralded single photons in the telecom wavelength range with purity of at least 0.95, and we provide a feasible fabrication methodology.

  13. Second-harmonic generation in periodically-poled thin film lithium niobate wafer-bonded on silicon.

    PubMed

    Rao, Ashutosh; Malinowski, Marcin; Honardoost, Amirmahdi; Talukder, Javed Rouf; Rabiei, Payam; Delfyett, Peter; Fathpour, Sasan

    2016-12-26

    Second-order optical nonlinear effects (second-harmonic and sum-frequency generation) are demonstrated in the telecommunication band by periodic poling of thin films of lithium niobate wafer-bonded on silicon substrates and rib-loaded with silicon nitride channels to attain ridge waveguide with cross-sections of ~2 µm2. A nonlinear conversion of 8% is obtained with a pulsed input in 4 mm long waveguides. The choice of silicon substrate makes the platform potentially compatible with silicon photonics, and therefore may pave the path towards on-chip nonlinear and quantum-optic applications.

  14. Enhancement of photorefractive sensitivity in indium-doped lithium niobate crystal

    NASA Astrophysics Data System (ADS)

    Qiao, Haijun; Xu, Jingjun; Wu, Qiang; Yu, Xuanyi; Zhang, Xinzheng; Zhang, Guangyin

    2002-09-01

    The photorefractive effect in Indium-doped litium niobate crystal was studied. We found that the enhanced photorefractive sensitivity could be realized in the so-called photorefractive resistance lithium niobate crystals, even higher than the well-known iron doped ones. We explained the unusual qualitatively. The experimental result enriches us the knowledge of the properties of doped lithium niobate crystals and provides some advice in growing specific crystal.

  15. Photo-written three-dimensional optical circuits in iron doped lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Zhang, Peng; Zhao, Jianlin; Xu, Honglai; Ma, Yanghua; Yang, Dexing

    2006-02-01

    We present our experimental results on fabricating optical waveguides by laser micromachining, structure-light illuminating, and optical spatial dark solitons in iron doped lithium niobate (LiNbO 3:Fe) crystals. After that we propose a novel approach to fabricate three-dimensional (3-D) optical circuits in LiNbO 3 crystals by combining the three light-induction techniques listed above. By employing laser micromachining, a curved and a Y-branches waveguides are successfully fabricated. With binary and SLM-prepared optical masks, Y-branches and gradient planar waveguides are experimentally demonstrated. By utilizing one-dimensional (1-D) optical spatial dark solitons, planar, Y-branches, and square channel waveguides are formed. The results show that each of the three methods can be employed to write optical waveguides in LiNbO3 crystals. By combing the three methods, 3-D light circuits can be created in 45 °-cut bulk crystals by several procedures. Initially, a quasi-planar optical circuit is created in a thin layer of the crystal by structure-light illuminating with an optical mask. Then, a planar circuit is generated by utilizing a 1-D dark soltion. And then, form multi-layer planar circuits are formed by altering the positions of the crystal or writing beam. Finally, laser micromachining is used to link the different layers to form a 3-D light circuit. Furthermore, functional 3-D integrated optical system may be implemented by using the proposed approach.

  16. Fabrication of p-type lithium niobate crystals by molybdenum doping and polarization

    NASA Astrophysics Data System (ADS)

    Tian, Tian; Kong, Yongfa; Liu, Hongde; Liu, Shiguo; Li, Wei; Chen, Shaolin; Xu, Jiayue

    2017-06-01

    The lack of p-type lithium niobate limits it serving as an active material. A series of Mo-doped and pure congruent lithium niobate crystals were grown by Czochralski method under different polarization conditions. Their dominant carrier species were characterized by holographic experiment. The results showed dominant charge carrier species may be changed from electrons to holes when lithium niobate crystal was doped with Mo ions and polarized under the current of 70mA for 30 minutes. It indicated that p-type lithium niobate crystal could be fabricated by Mo-doping and suitably controlling the polarization condition. Mo-doped lithium niobate crystals can be a promising candidate for active components.

  17. A Novel Inter Core-Cladding Lithium Niobate Thin Film Coated Fiber Modulator/Sensor

    NASA Technical Reports Server (NTRS)

    Jamison, Tracee L.; Komriech, Phillip; Yu, Chung

    2004-01-01

    A fiber modulator/sensor has been fabricated by depositing a lithium niobate sol-gel thin film between the core and cladding of a fiber preform. The preform is then drawn into 125 micron fiber. The proposed design of lithium niobate cylinder fibers can enhance the existing methodology for detecting sound waves under water utilizing the acoustooptic properties of lithium niobate. Upon application of a stress or strain, light propagating inside the core, according to the principle of total internal reflection, escapes, into the cladding because of the photoelastic boundary layer of lithium niobate. Test results of the lithium niobate fiber reveal a reduction in the 1550 nm, 4mW source with applied tension. The source power from an ordinary quartz fiber under the same stress condition remained invariant to applied tension.

  18. Surface Acoustic Wave Non-Linear Interactions in Lithium Niobate.

    DTIC Science & Technology

    1983-01-01

    X and Y, Z lithium niobate were investigated for two different angles of interaction. The mixed frequency was at least 8. 5 dB weaker than the...Introduction ............................ 165 5.2 Results for Y,Z LiNb0 3 with w1/w,22.6o ........................ 0............ 166 5.3 Results for 38, X ...LiNbO 3 with 11/w20.41 .................................... 173 *5.14 Results for 38, X LiNbO3 with (-1/’ 2 2.44 .. . . . ...... .. .. ...... 179 i Vi

  19. Anisotropic diffraction of bulk acoustic wave beams in lithium niobate.

    PubMed

    Naumenko, Natalya F; Chizhikov, Sergey I; Molchanov, Vladimir Ya; Yushkov, Konstantin B

    2015-12-01

    The formalism of planar diffraction tensor was applied to the analysis of anisotropy of bulk acoustic wave diffraction and to build a full map of anisotropic diffractional coefficients for three bulk acoustic wave modes propagating in lithium niobate. For arbitrary propagation direction the diffractional coefficients derived allow estimation of ultrasonic beam divergence in far-field. Analysis of obtained data revealed that the maxima of acousto-optic figure of merit for anisotropic diffraction in the YZ plane correspond to moderate diffractional spreading of the beams exceeding isotropic diffraction 2-3 times.

  20. Lithium niobate single-crystal and photo-functional device

    DOEpatents

    Gopalan, Venkatraman; Mitchell, Terrence E.; Kitamura, Kenji; Furukawa, Yasunori

    2001-01-01

    Provided are lithium niobate single-crystal that requires a low voltage of not larger than 10 kV/nm for its ferroelectric polarization inversion and of which the polarization can be periodically inverted with accuracy even at such a low voltage, and a photo-functional device comprising the crystal. The crystal has a molar fraction of Li.sub.2 O/(Nb.sub.2 O.sub.5 +Li.sub.2 O) of falling between 0.49 and 0.52. The photo-functional device can convert a laser ray being incident thereon.

  1. Deposition of potassium lithium niobate films by sol-gel method

    NASA Astrophysics Data System (ADS)

    Zhang, Hong X.; Zhou, Yan; Kam, Chan Hin; Han, X. Q.; Cheng, Shi De; Ooi, Boon Siew; Lam, Yee Loy; Chan, Yuen Chuen; Sun, Zhuo; Yu, M. B.; Shi, Xu; Yoon, Soon Fatt

    1999-11-01

    Potassium lithium niobate (KLN) films have been prepared by sol-gel method using metal ethoxides as starting materials. The films were deposited by spin coating and were annealed in air in a conventional oven as well as in a rapid thermal processor (RTP). X-ray diffraction and Raman scattering measurements have shown that polycrystalline KLN films with tetragonal tungsten-bronze-type structure could be obtained on both SiO2 buffered Si and fused quartz substrates. Surface morphology studies indicated that RTP annealing could avoid film cracking and enable nanostructured low- surface roughness KLN films to be formed. Optical waveguiding experiments showed that the films have refractive indices close to those of their single crystal and could support several modes. The films deposited on fused quartz were highly transparent in the visible-near IR spectral range and the absorption edges of the films, as determined from the absorption data, were found to shift towards the violet spectral side.

  2. A Novel Coupled Resonator Photonic Crystal Design in Lithium Niobate for Electrooptic Applications

    DOE PAGES

    Ozturk, Birol; Yavuzcetin, Ozgur; Sridhar, Srinivas

    2015-01-01

    High-aspect-ratio photonic crystal air-hole fabrication on bulk Lithium Niobate (LN) substrates is extremely difficult due to its inherent resistance to etching, resulting in conical structures and high insertion losses. Here, we propose a novel coupled resonator photonic crystal (CRPC) design, combining a coupled resonator approach with that of Bragg gratings. CRPC design parameters were optimized by analytical calculations and FDTD simulations. CRPC structures with optimized parameters were fabricated and electrooptically tested on bulk LN annealed proton exchange waveguides. Low insertion loss and large electrooptic effect were observed with the fabricated devices, making the CRPC design a promising structure for electroopticmore » device applications.« less

  3. Li Storage of Calcium Niobates for Lithium Ion Batteries.

    PubMed

    Yim, Haena; Yu, Seung-Ho; Yoo, So Yeon; Sung, Yung-Eun; Choi, Ji-Won

    2015-10-01

    New types of niobates negative electrode were studied for using in lithium-ion batteries in order to alternate metallic lithium anodes. The potassium intercalated compound KCa2Nb3O10 and proton intercalated compound HCa2Nb3O10 were studied, and the electrochemical results showed a reversible cyclic voltammetry profile with acceptable discharge capacity. The as-prepared KCa2Nb3O10 negative electrode had a low discharge capacity caused by high overpotential, but the reversible intercalation and deintercalation reaction of lithium ions was activated after exchanging H+ ions for intercalated K+ ions. The initial discharge capacity of HCa2Nb3O10 was 54.2 mAh/g with 92.1% of coulombic efficiency, compared with 10.4 mAh/g with 70.2% of coulombic efficiency for KCa2Nb3O10 at 1 C rate. The improved electrochemical performance of the HCa2Nb3O10 was related to the lower bonding energy between proton cation and perovskite layer, which facilitate Li+ ions intercalating into the cation site, unlike potassium cation and perovskite layer. Also, this negative material can be easily exfoliated to Ca2Nb3O10 layer by using cation exchange process. Then, obtained two-dimensional nanosheets layer, which recently expected to be an advanced electrode material because of its flexibility, chemical stable, and thin film fabricable, can allow Li+ ions to diffuse between the each perovskite layer. Therefore, this new type layered perovskite niobates can be used not only bulk-type lithium ion batteries but also thin film batteries as a negative material.

  4. Changes in the reflectivity of a lithium niobate crystal decorated with a graphene layer

    NASA Astrophysics Data System (ADS)

    Salas, O.; Garcés, E.; Castillo, F. L.; Magaña, L. F.

    2017-01-01

    Density functional theory and molecular dynamics were used to study the interaction of a graphene layer with the surface of lithium niobate. The simulations were performed at atmospheric pressure and 300K. We found that the graphene layer is physisorbed with an adsorption energy of -0.8205 eV/C-atom. Subsequently, the optical absorption of the graphene-(lithium niobate) system was calculated and compared with that of graphene solo and lithium niobate alone, respectively. The calculations were performed using the Quantum Espresso code with the GGA approximation and Vdw-DF2 (which includes long-range correlation effects as Van der Waals interactions).

  5. Absorption and reflectivity of the lithium niobate surface masked with a graphene layer

    NASA Astrophysics Data System (ADS)

    Salas, O.; Garcés, E.; Castillo, F. L.; Magaña, L. F.

    2017-01-01

    We performed simulations of the interaction of a graphene layer with the surface of lithium niobate utilizing density functional theory and molecular dynamics at 300K and atmospheric pressure. We found that the graphene layer is physisorbed on the lithium niobate surface with an adsorption energy of -0.8205 eV/(carbon-atom). Subsequently, the energy band structure, the optical absorption and reflectivity of the new system were calculated. We found important changes in these physical properties with respect to the corresponding ones of a graphene layer and of a lithium niobate crystal.

  6. Tunable Bloch surface waves in anisotropic photonic crystals based on lithium niobate thin films.

    PubMed

    Kovalevich, Tatiana; Ndao, Abdoulaye; Suarez, Miguel; Tumenas, Saulius; Balevicius, Zigmas; Ramanavicius, Arunas; Baleviciute, Ieva; Häyrinen, Markus; Roussey, Matthieu; Kuittinen, Markku; Grosjean, Thierry; Bernal, Maria-Pilar

    2016-12-01

    We present an original type of one-dimensional photonic crystal that includes one anisotropic layer made of a lithium niobate thin film. We demonstrate the versatility of such a device sustaining different Bloch surface waves (BSWs), depending on the orientation of the incident wave. By varying the orientation of the illumination of the multilayer, we measured an angle variation of 7° between the BSWs corresponding to the extraordinary and the ordinary index of the lithium niobate thin film. The potential of such a platform opens the way to novel tunable and active planar optics based on the electro- and thermo-optical properties of lithium niobate.

  7. Easy and versatile functionalization of lithium niobate wafers by hydrophobic trichlorosilanes

    NASA Astrophysics Data System (ADS)

    Bennès, Jonathan; Ballandras, Sylvain; Chérioux, Frédéric

    2008-12-01

    The functionalization of lithium niobate surface has been successfully obtained by the grafting of trichloro-organosilane derivatives thanks to liquid phase silanization or micro-contact printing. This functionalization has been proved by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The data show that the stability of the self-assembled monolayer (SAM) film on the trichloro(1H,1H,2H,2H-perfluorooctyl)silane-modified lithium niobate surface is largely due to the formation of a siloxy-niobate (-Si-O-Nb-) bond via a condensation reaction between -Si-Cl and niobate hydroxide (-NbOH). The extremely hydrophobic and stable SAM on lithium niobate could have useful applications in acoustic droplet handling and more generally surface acoustic waves (SAW) device preparation for lab-on-chip devices.

  8. Second-harmonic generation in periodically-poled thin film lithium niobate wafer-bonded on silicon

    NASA Astrophysics Data System (ADS)

    Rao, Ashutosh; Malinowski, Marcin; Honardoost, Amirmahdi; Talukder, Javed Rouf; Rabiei, Payam; Delfyett, Peter; Fathpour, Sasan

    2016-12-01

    Second-order optical nonlinear effects (second-harmonic and sum-frequency generation) are demonstrated in the telecommunication band by periodic poling of thin films of lithium niobate wafer-bonded on silicon substrates and rib-loaded with silicon nitride channels to attain ridge waveguide with cross-sections of ~ 2 {\\mu}m2. The compactness of the waveguides results in efficient second-order nonlinear devices. A nonlinear conversion of 8% is obtained with a pulsed input in 4 mm long waveguides. The choice of silicon substrate makes the platform potentially compatible with silicon photonics, and therefore may pave the path towards on-chip nonlinear and quantum-optic applications.

  9. Investigation of femtosecond laser assisted nano and microscale modifications in lithium niobate

    NASA Astrophysics Data System (ADS)

    Deshpande, Devesh C.; Malshe, Ajay P.; Stach, Eric A.; Radmilovic, Velimir; Alexander, Dennis; Doerr, David; Hirt, Drew

    2005-04-01

    A study of the physicochemical modifications at micro and nano scales as a result of femtosecond laser processing is essential to explore the viability of this process to write surface and subsurface structures in transparent media. To this end, scanning probe and transmission electron microscopy and spectroscopy techniques were used to study these modifications in lithium niobate. A variable power Ti:Sapphire system (800nm,300fs) was used to determine the ablation threshold of (110) lithium niobate, and to write these structures in the substrate for subsequent analysis. Higher processing energies were used to amplify the laser-induced effects for a clear understanding. Evidences of a number of simultaneously occurring mechanisms such as melting, ablation, and shockwave propagation are observed in the scanning electron microscope (SEM) micrographs. X-ray diffraction (XRD), Auger and electron dispersive spectroscopy (EDS) studies indicate loss of lithium and oxygen from the immediate surface of the processed region. Raman spectroscopy analysis indicates an unchanged chemical composition in the bulk, though at a loss of crystallinity. The surface and subsurface damage structures display a different nature of the amorphous and damaged material subregions, as observed in the respective transmission electron microscopy micrographs. A variation in oxygen counts is observed in the amorphous subregions, indicative of oxygen liberation and elemental segregation during the process. The oblate subsurface structure contains a void at the top, indicative of localized explosive melting and rapid quenching of the affected material. Thus, femtosecond laser writing produces different structures on the surface and the subsurface of the material. These results provide physicochemical insight towards writing chemically and spatially precise structures using femtosecond lasers, and will have direct implications in optical memory and waveguide writing and related applications.

  10. Novel intercore-cladding lithium niobate thin film coated MOEMS fiber sensor/modulator

    NASA Technical Reports Server (NTRS)

    Jamlson, Tracee L.; Konreich, Phillip; Yu, Chung

    2005-01-01

    A MOEMS fiber modulator/sensor is fabricated by depositing a lithium niobate sol-gel thin film between the core and cladding of a fiber preform. The preform is then drawn into 125-micron fibers. Such a MOEMS modulator design is expected to enhance existing lithium niobate undersea acousto-optic sound wave detectors. In our proposed version, the lithium niobate thin film alters the ordinary silica core/cladding boundary conditions such that, when a stress or strain is applied to the fiber, the core light confinement factor changes, leading to modulation of fiber light transmission. Test results of the lithium niobate embedded fiber with a 1550-nm, 4-mW laser source revealed a reduction in light transmission with applied tension. As a comparison, using the same laser source, an ordinary silica core/cladding fiber did not exhibit any reduction in transmitted light when the same strain was applied. Further experimental work and theoretical analysis is ongoing.

  11. Novel intercore-cladding lithium niobate thin film coated MOEMS fiber sensor/modulator

    NASA Technical Reports Server (NTRS)

    Jamlson, Tracee L.; Konreich, Phillip; Yu, Chung

    2005-01-01

    A MOEMS fiber modulator/sensor is fabricated by depositing a lithium niobate sol-gel thin film between the core and cladding of a fiber preform. The preform is then drawn into 125-micron fibers. Such a MOEMS modulator design is expected to enhance existing lithium niobate undersea acousto-optic sound wave detectors. In our proposed version, the lithium niobate thin film alters the ordinary silica core/cladding boundary conditions such that, when a stress or strain is applied to the fiber, the core light confinement factor changes, leading to modulation of fiber light transmission. Test results of the lithium niobate embedded fiber with a 1550-nm, 4-mW laser source revealed a reduction in light transmission with applied tension. As a comparison, using the same laser source, an ordinary silica core/cladding fiber did not exhibit any reduction in transmitted light when the same strain was applied. Further experimental work and theoretical analysis is ongoing.

  12. Direct-writing of inverted domains in lithium niobate using a continuous wave ultra violet laser.

    PubMed

    Muir, A C; Sones, C L; Mailis, S; Eason, R W; Jungk, T; Hoffman, A; Soergel, E

    2008-02-18

    The inversion of ferroelectric domains in lithium niobate by a scanning focused ultra-violet laser beam (lambda = 244 nm) is demonstrated. The resulting domain patterns are interrogated using piezoresponse force microscopy and by chemical etching in hydrofluoric acid. Direct ultra-violet laser poling was observed in un-doped congruent, iron doped congruent and titanium in-diffused congruent lithium niobate single crystals. A model is proposed to explain the mechanism of domain inversion.

  13. Optical planar waveguide in sodium-doped calcium barium niobate crystals by carbon ion implantation

    NASA Astrophysics Data System (ADS)

    Zhao, Jin-Hua; Qin, Xi-Feng; Wang, Feng-Xiang; Fu, Gang; Wang, Hui-Lin; Wang, Xue-Lin

    2013-07-01

    There is great interest in niobate crystals which belong to the tetragonal tungsten bronze (TTB) families owing to their intriguing properties. As one representative of such crystals, CBN (calcium barium niobate) has attracted rapidly growing attention. Because it has a higher Curie temperature than SBN (strontium barium niobate), possesses outstanding ferroelectric and it possesses optical properties. In addition, doped with sodium, CBN will show a higher Curie temperature than pure CBN. We report on the fabrication and characterization of optical planar waveguide in x-cut sodium-doped calcium barium niobate crystal by using C ion implantation. The guided-mode properties at the wavelength of 633 and 1539 nm are investigated through prism-coupling measurements, respectively. By applying direct end-face coupling arrangement, the near-field optical intensity distribution of waveguide modes is measured at 633 nm. For comparison, the modal profile of the same guided mode is also numerically calculated by the finite difference beam-propagation method via computer software BeamPROP. The transmission spectra of the waveguide before and after ion implantation treatments were investigated also. Our experiment results reveal that the waveguide could propagate light with transverse magnetic polarized direction only and it is assumed that the polarization selectivity of CBN crystal may responsible for this phenomenon.

  14. Holographic surface gratings in iron-doped lithium niobate

    SciTech Connect

    Sarkisov, S. S.; Curley, M. J.; Kukhtarev, N. V.; Fields, A.; Adamovsky, G.; Smith, C. C.; Moore, L. E.

    2001-08-13

    Surface gratings associated with holographic volume gratings in photorefractive crystals of iron-doped lithium niobate have been studied using diffraction of a reflected probe beam and high-resolution phase-shifted interferometric profilometry. Both techniques show that the surface gratings exist in the form of periodical corrugations of the same period as that of the volume grating. The maximum amplitude of the periodical surface relief measured by both techniques is close to 6.5 nm. We also demonstrated that the periodical electric forces on the surface were capable of assembling polystyrene microspheres along the fringes of the grating. Large amplitude of the periodic electric field (1.6 x 10{sup 4}V/cm) is associated with the photogalvanic effect. {copyright} 2001 American Institute of Physics.

  15. Generation and tunable enhancement of a sum-frequency signal in lithium niobate nanowires

    NASA Astrophysics Data System (ADS)

    Sergeyev, Anton; Reig Escalé, Marc; Grange, Rachel

    2017-02-01

    Recent developments in the fabrication of lithium niobate (LiNbO3) structures down to the nanoscale opens up novel applications of this versatile material in nonlinear optics. Current nonlinear optical studies in sub-micron waveguides are mainly restricted to the generation of second and third harmonics. In this work, we demonstrate the generation and waveguiding of the sum-frequency generation (SFG) signal in a single LiNbO3 nanowire with a cross-section of 517 nm  ×  654 nm. Furthermore, we enhance the guided SFG signal 17.9 times by means of modal phase matching. We also display tuning of the phase-matched wavelength by varying the nanowire cross-section and changing the polarization of the incident laser. The results prove that LiNbO3 nanowires can be successfully used for nonlinear wave-mixing applications and assisting the miniaturization of optical devices. , which features invited work from the best early-career researchers working within the scope of J Phys D. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Rachel Grange was selected by the Editorial Board of J Phys D as an Emerging Leader.

  16. Growth, defect structure, and THz application of stoichiometric lithium niobate

    NASA Astrophysics Data System (ADS)

    Lengyel, K.; Péter, Á.; Kovács, L.; Corradi, G.; Pálfalvi, L.; Hebling, J.; Unferdorben, M.; Dravecz, G.; Hajdara, I.; Szaller, Zs.; Polgár, K.

    2015-12-01

    Owing to the extraordinary richness of its physical properties, congruent lithium niobate has attracted multidecade-long interest both for fundamental science and applications. The combination of ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as the strong photorefractive and photovoltaic effects offers a great potential for applications in modern optics. To provide powerful optical components in high energy laser applications, tailoring of key material parameters, especially stoichiometry, is required. This paper reviews the state of the art of growing large stoichiometric LiNbO3 (sLN) crystals, in particular, the defect engineering of pure and doped sLN with emphasis on optical damage resistant (ODR) dopants (e.g., Mg, Zn, In, Sc, Hf, Zr, Sn). The discussion is focused on crystals grown by the high temperature top seeded solution growth (HTTSSG) technique using alkali oxide fluxing agents. Based on high-temperature phase equilibria studies of the Li2O-Nb2O5-X2O ternary systems (X = Na, K, Rb, Cs), the impact of alkali homologue additives on the stoichiometry of the lithium niobate phase will be analyzed, together with a summary of the ultraviolet, infrared, and far-infrared absorption spectroscopic methods developed to characterize the composition of the crystals. It will be shown that using HTTSSG from K2O containing flux, crystals closest to the stoichiometric composition can be grown characterized by a UV-edge position of at about 302 nm and a single narrow hydroxyl band in the IR with a linewidth of less than 3 cm-1 at 300 K. The threshold concentrations for ODR dopants depend on crystal stoichiometry and the valence of the dopants; Raman spectra, hydroxyl vibration spectra, and Z-scan measurements prove to be useful to distinguish crystals below and above the photorefractive threshold. Crystals just above the threshold are preferred for most nonlinear optical applications apart

  17. EFFECT OF LASER LIGHT ON MATTER. LASER PLASMAS: Laser damage resistance of a lithium niobate-tantalate bicrystal system

    NASA Astrophysics Data System (ADS)

    Skvortsov, L. A.; Stepantsov, E. S.

    1993-11-01

    The laser damage resistance of a bicrystal system prepared by solid-phase diffusive joining of specially prepared crystals of lithium niobate and lithium tantalate has been studied. This has been the first such study. The damage resistance of the interface is at least twice that of the lithium niobate surface. The damage resistance of the bicrystal is determined by the damage resistance of the lithium tantalate surface and is greater than 600 MW/cm2.

  18. Generation of ionizing radiation from lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Orlikov, L. N.; Orlikov, N. L.; Arestov, S. I.; Mambetova, K. M.; Shandarov, S. M.

    2017-01-01

    The work done experimentally explores generation of electron and x-ray radiation in the process of heating and cooling monolithic and iron-doped crystals of lithium niobate. Iron doping to the concentrations in the range of 1023 m3 was carried out by adding ferric oxide into the melt during the process of crystal growth. The research into radiation generation was performed at 1-10 Pa. The speed of heating from -10 to 1070 C was 10-20 degrees a minute. Current pulses appeared at 17, 38, 56, 94, 98, 100, 105, 106, 1070 C with the interval of 1-3 minutes. The obtained electron current increased in direct proportion to the crystal surface area. The maximum current was 3mA at the design voltage 11 kV on the crystal with 14,5x10,5x10 mm3 surface area. The article describes the possibility to control the start of generation by introducing priming pulse. The results achieved are explained by the domain repolarization while heating the crystal and the appearance of electric field local strength. Bias and overcharge currents contribute to the appearance of electric strength, which stimulates breakdown and plasma formation. X-ray radiation appears both at the stage of discharge formation and during electron deceleration on gas and target material.

  19. Diamond micro-milling of lithium niobate for sensing applications

    NASA Astrophysics Data System (ADS)

    Huo, Dehong; Jie Choong, Zi; Shi, Yilun; Hedley, John; Zhao, Yan

    2016-09-01

    Lithium niobate (LiNbO3) is a crystalline material which is widely applied in surface acoustic wave, microelectromechanical systems (MEMS), and optical devices, owing to its superior physical, optical, and electronic properties. Due to its low toughness and chemical inactivity, LiNbO3 is considered to be a hard-to-machine material and has been traditionally left as as an inert substrate upon which other micro structures are deposited. However, in order to make use of its superior material properties and increase efficiency, the fabrication of microstructures directly on LiNbO3 is in high demand. This paper presents an experimental investigation on the micro machinability of LiNbO3 via micro milling with the aim of obtaining optimal process parameters. Machining of micro slots was performed on Z-cut LiNbO3 wafers using single crystal diamond tools. Surface and edge quality, cutting forces, and the crystallographic effect were examined and characterized. Ductile mode machining of LiNbO3 was found to be feasible at a low feed rate and small depth of cut. A strong crystallographic effect on the machined surface quality was also observed. Finally, some LiNbO3 micro components applicable to sensing applications were fabricated.

  20. Acoustic wave filter based on periodically poled lithium niobate.

    PubMed

    Courjon, Emilie; Bassignot, Florent; Ulliac, Gwenn; Benchabane, Sarah; Ballandras, Sylvain

    2012-09-01

    Solutions for the development of compact RF passive transducers as an alternative to standard surface or bulk acoustic wave devices are receiving increasing interest. This article presents results on the development of an acoustic band-pass filter based on periodically poled ferroelectric domains in lithium niobate. The fabrication of periodically poled transducers (PPTs) operating in the range of 20 to 650 MHz has been achieved on 3-in (76.2-mm) 500-μm-thick wafers. This kind of transducer is able to excite elliptical as well as longitudinal modes, yielding phase velocities of about 3800 and 6500 ms(-1), respectively. A new type of acoustic band-pass filter is proposed, based on the use of PPTs instead of the SAWs excited by classical interdigital transducers. The design and the fabrication of such a filter are presented, as well as experimental measurements of its electrical response and transfer function. The feasibility of such a PPT-based filter is thereby demonstrated and the limitations of this method are discussed.

  1. Acoustic spectroscopy of lithium niobate: Elastic and piezoelectric coefficients

    NASA Astrophysics Data System (ADS)

    Ogi, Hirotsugu; Kawasaki, Yasunori; Hirao, Masahiko; Ledbetter, Hassel

    2002-09-01

    We report simultaneous measurement of the complete set of elastic and piezoelectric coefficients of lithium niobate (LiNbO3), which has trigonal crystal symmetry (3m point group) and thus six independent elastic-stiffness coefficients Cij, four piezoelectric coefficients eij, and two dielectric coefficients kappaij. We used a single specimen: an oriented rectangular parallelepiped about 5 mm in size. Our measurement method, acoustic spectroscopy, focuses on the crystal's macroscopic resonance frequencies and is sensitive to any property that affects those frequencies. We overcame the principal obstacle to precise measurements--mode misidentification--by using laser-Doppler interferometry to detect the displacement distribution on a vibrating surface. This approach yields unambiguous mode identification. We used 56 resonances ranging in frequency from 0.3 to 1.2 MHz and determined the Cij and eij with known kappaij. The ten unknowns always converged to the same values even with unreasonable initial guesses. The Cij uncertainty averages 0.09% for the diagonal Cij. The eij uncertainty averages 5%. All our coefficients fall within the (surprisingly wide) error limits of previous (conventional) measurements.

  2. Determining the sign of a polar surface of lithium niobate crystal by UV reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Paranin, V. D.; Pantelei, E.

    2017-01-01

    We propose to reveal the + Z and- Z surfaces of a polar cut lithium niobate crystal by measuring its UV reflection spectrum. By the example of a congruent lithium niobate, it is shown that the intensities of light reflection from polar crystal surfaces of different signs in the region of 190—260 nm differ by up to several percent. The depth of short-wave radiation penetration into surface layers of the crystal in the spectral range of intrinsic absorption is estimated. It is shown that the proposed method can be used for determining the surface signs of polar crystal layers with thicknesses from several dozen to several hundred microns.

  3. Novel refractive index biosensing of microcontact printed molecules on lithium niobate.

    PubMed

    Bhalla, Nikhil; Sathish, Shivani; Shen, Amy Q

    2016-08-01

    This work demonstrates, for the first time, the use of lithium niobate as a biosensor that detects local refractive index changes triggered by the presence of biomolecules on its surface. The sensitivity of the sensor was found to be 242±16 nm/RIU. As a case study, we immobilized proteins (IgG antibodies) using micro-contact printing to demonstrate sensing capabilities of the device. The validated proof of concept lays a foundation for developing lithium niobate based novel optical biosensors.

  4. Tunable dual-wavelength filter and its group delay dispersion in domain-engineered lithium niobate

    NASA Astrophysics Data System (ADS)

    Shao, Guang-hao; Song, Jing; Ruan, Ya-ping; Cui, Guo-xin; Lu, Yan-qing

    2016-12-01

    A tunable dual-wavelength filter is experimentally demonstrated in domain-engineered lithium niobate. Application of an electric field on the y-surfaces of the sample results in the optical axes rotating clockwise and anticlockwise, which makes selective polarization rotation. The quasi phase-matching wavelengths could be adjusted through suitable domain design. A unique dual valley spectrum is obtained in a periodically poled lithium niobate structure with a central defect if the sample is placed between two parallel polarizers. The expected bandwidth could be varied from ˜1 nm to ˜40 nm. Moreover, both the spectral response and group delay dispersion could be engineered.

  5. Two telescopes ABCD electro-optic beam combiner based on lithium niobate for near infrared stellar interferometry

    NASA Astrophysics Data System (ADS)

    Heidmann, S.; Caballero, O.; Nolot, A.; Gineys, M.; Moulin, T.; Delboulbé, A.; Jocou, L.; Le Bouquin, J.-B.; Berger, J.-P.; Martin, G.

    2011-06-01

    Lithium Niobate (LN) based electro-optic modulators are well known in the optical communications field, due to their high bandwidth and deep rejection ratio [1]. These performances could be used in the field of astronomy for stellar interferometry in the mid-infrared domain [2]. With our partners from Photline Technologies, we have conceived, developed and characterized a 2T ABCD [3] beam combiner in the near-infrared (1.5μm, the H-band in astrophysics). The modulation scheme, presented below in Figure 1, allows to determine the fringe characteristics in a single shot measurement, without the need to externally scan the optical phase delay. Fine adjustment of the relative phase can be achieved using the electro-optic properties of the lithium niobate waveguides. In particular, the phase on each output can be electrically controlled and locked by using appropriate electrodes. These devices have to ensure modal filtering to reject optical aberrations of the wavefront and thus optimize the fringes contrast, which means that they have to be single mode through all the spectral range of interest. This also means that the couplers should be achromatic and balanced in order to optimize the fringe contrast. We will present results on global transmission, performance of the couplers and the electro-optic behavior of the device using monochromatic as well as wide spectral sources in the H-band.

  6. Li K-Edge XANES Spectra of Lithium Niobate and Lithium Tantalite

    SciTech Connect

    Mizota, H.; Ito, Y.; Tochio, T.; Handa, K.; Takekawa, S.; Kitamura, K.

    2007-02-02

    The x-ray emission with the single crystal of lithium niobate (LiNbO3) or lithium tantalite (LiTaO3) by thermal changes in a vacuum system is closely concerned with the electronic state of each crystal. Therefore, lithium K-edge x-ray absorption near edge structures (XANES) spectra of these materials were measured in the region from 50 eV to 90 eV by means of total electron yield method (T.E.Y.), using the extremely soft x-ray. Samples were powder of lithium carbonate (Li2CO3) and single crystal of lithium fluoride (LiF), LiNbO3 and LiTaO3 in order to compare the shapes of these XANES spectra. Various peak structures appear in these spectra in the range from 55 eV to 80 eV and each spectrum has different shapes as a result of the difference of bond length and bond angles for the atoms which are in less than 60 nm from the absorbing atom. The relationship between these spectra and the electronic states was discussed by FEFF 8.

  7. Picosecond cubic and quintic nonlinearity of lithium niobate at 532 nm

    NASA Astrophysics Data System (ADS)

    Wang, Hongzhen; Boudebs, Georges; de Araújo, Cid B.

    2017-08-01

    The nonlinear (NL) optical response of bulk lithium niobate (LiNbO3) was investigated at 532 nm using the second harmonic of a Nd:YAG laser delivering pulses of 12 ps. The experiments were performed using the D4σ method combined with the conventional Z-scan technique. Two- and three-photon absorption coefficients equal to 0.27 c m /G W and 2.5 ×10-26 m3/W2, respectively, were determined. The NL absorption processes were due to transitions from the valence to the conduction band and to free-carrier absorption. The third- and fifth-order NL refractive indices were n2=(2.5 ±0.6 )×10-19 m2/W and n4<5.5 ×10-36 m4/W2. The present results give the support for previous experiments that indicate possible fifth-order processes in bulk samples and channel waveguides fabricated with LiNbO3.

  8. Growth, defect structure, and THz application of stoichiometric lithium niobate

    SciTech Connect

    Lengyel, K.; Péter, Á.; Kovács, L.; Corradi, G.; Dravecz, G.; Hajdara, I.; Szaller, Zs.; Polgár, K.; Pálfalvi, L.; Unferdorben, M.; Hebling, J.

    2015-12-15

    Owing to the extraordinary richness of its physical properties, congruent lithium niobate has attracted multidecade-long interest both for fundamental science and applications. The combination of ferro-, pyro-, and piezoelectric properties with large electro-optic, acousto-optic, and photoelastic coefficients as well as the strong photorefractive and photovoltaic effects offers a great potential for applications in modern optics. To provide powerful optical components in high energy laser applications, tailoring of key material parameters, especially stoichiometry, is required. This paper reviews the state of the art of growing large stoichiometric LiNbO{sub 3} (sLN) crystals, in particular, the defect engineering of pure and doped sLN with emphasis on optical damage resistant (ODR) dopants (e.g., Mg, Zn, In, Sc, Hf, Zr, Sn). The discussion is focused on crystals grown by the high temperature top seeded solution growth (HTTSSG) technique using alkali oxide fluxing agents. Based on high-temperature phase equilibria studies of the Li{sub 2}O–Nb{sub 2}O{sub 5}–X{sub 2}O ternary systems (X = Na, K, Rb, Cs), the impact of alkali homologue additives on the stoichiometry of the lithium niobate phase will be analyzed, together with a summary of the ultraviolet, infrared, and far-infrared absorption spectroscopic methods developed to characterize the composition of the crystals. It will be shown that using HTTSSG from K{sub 2}O containing flux, crystals closest to the stoichiometric composition can be grown characterized by a UV-edge position of at about 302 nm and a single narrow hydroxyl band in the IR with a linewidth of less than 3 cm{sup −1} at 300 K. The threshold concentrations for ODR dopants depend on crystal stoichiometry and the valence of the dopants; Raman spectra, hydroxyl vibration spectra, and Z-scan measurements prove to be useful to distinguish crystals below and above the photorefractive threshold. Crystals just above the threshold are

  9. Lithium-niobate-based integrated optic chip utilizing digital electrode layout for use in a miniature fiber optic rate sensor

    NASA Astrophysics Data System (ADS)

    Ner, Manjeet S.; Groellmann, Peter; Mutter, Gerhard

    1995-09-01

    This paper describes to the best of our knowledge the first implementation of a lithium niobate based 8 bit electroded integrated optic waveguide fiber optic gyro chip referred here as 'Digi- MIOC' (digital-electroded multifunction integrated optic chip, which has been used in a Sagnac effect exploiting microfiber optic rate sensor ((mu) -FORS) developed by LITEF. The paper highlights various features of a Digi-MIOC, such as design philosophy, fabrication aspects, and test procedures to evaluate static and dynamic characteristics of the electro-optic parameters. When used in closed loop operation, the Digi-MIOC forms the key optical component of a (mu) -FORS to aid the required optical-to-electrical signal processing to give linear output for input rates of rotation. Various test results and features of LITEF's (mu) - FORS, such as small size, large rotation rate measurement potential, low drive power, and high reliabliity are also highlighted.

  10. Surface acoustic wave generation and detection using graphene interdigitated transducers on lithium niobate

    SciTech Connect

    Mayorov, A. S.; Hunter, N.; Muchenje, W.; Wood, C. D.; Rosamond, M.; Linfield, E. H.; Davies, A. G.; Cunningham, J. E.

    2014-02-24

    We demonstrate the feasibility of using graphene as a conductive electrode for the generation and detection of surface acoustic waves at 100 s of MHz on a lithium niobate substrate. The graphene interdigitated transducers (IDTs) show sensitivity to doping and temperature, and the characteristics of the IDTs are discussed in the context of a lossy transmission line model.

  11. Enhanced Nonlinear Effect of Lithium Niobate Based Periodic Nano-antenna Array

    NASA Astrophysics Data System (ADS)

    Pei, X. L.; Bai, S. A.; Tian, J. Y.; Ghosh, P.; Li, Q.; Qiu, M.

    2017-06-01

    We report nonlinear properties of lithium niobate based periodic nano-antenna array. The resonances of this nano-antenna array can be engineered by tuning the geometrical parameters. The nonlinear effect gets enhanced when the electric and magnetic resonances overlap.

  12. Photorefractive properties of ion-implanted waveguides in strontium barium niobate crystals

    NASA Astrophysics Data System (ADS)

    Kip, D.; Kemper, B.; Nee, I.; Pankrath, R.; Moretti, P.

    1997-10-01

    Planar optical waveguides were formed in cerium-doped strontium barium niobate single crystals (Sr0.61Ba0.39Nb2O6, SBN61), either by proton or helium ion implantation. Proton-implanted samples show a large increase of dark conductivity that reduces or even prevents the recording of refractive index gratings. For waveguides formed by helium implantation this effect is absent, and they can be used for efficient holographic recording. Photorefractive properties of the waveguides are investigated by two-beam coupling. After implantation with 2.0 MeV He+ and doses of (0.5-5)񺔗 cm-2, the samples have to be polarized again, because heating or charge effects at the crystals surface during the implantation process decreases or even reverses the effective electrooptic coefficients in the waveguiding layer. For repoled samples, we find logarithmic gain coefficients of up to 45 cm-1 with time constants for the build-up of the purely ?/2-shifted refractive index grating of the order of 1 ms for the blue lines of an Ar+ laser. Photoconductivity depends nonlinearly on light intensity with an exponent xƸ.55. With increasing implanted helium dose, both electronic and nuclear damage of the waveguiding layer grows, and the photorefractive properties of the waveguides are considerably degraded.

  13. The laser conoscopy of lithium niobate crystals of different composition

    NASA Astrophysics Data System (ADS)

    Pikoul, O. Y.; Sidorov, N. V.; Teplyakova, N. A.; Palatnikov, M. N.

    2016-11-01

    In this paper we study conoscopic patterns of single crystals of LiNbO3 congruent (Li/Nb = 0.946) and stoichiometric (Li/Nb = 1) compounds, as well as congruent crystals doped with cations: Mg2+ (0.86 wt.%), Zn2+ (0.03, 0.52, 0.62 wt.%), Cu2 + (0.015 wt.%), B3+ (0.12 wt.%), Gd3+ (0.51 wt.%), Y3+ (0.46 wt.%), Gd3+ (0.23 wt.%): Mg2+ (0.75 wt.%), Mg2+ (0.86 wt.%): Fe3+ (0.0036 wt.%), Ta5+ (1.13 wt.%): Mg2+ (0.011 wt.%), Y3+ (0.24 wt.%): Mg2+ (0.63 wt.%). Conoscopic patterns of lithium niobate crystals were recorded at excitation by He-Ne laser (λo = 632.8 nm) and the second harmonic of MLL-100 laser Y:Al garnet (λo = 532 nm, P = 1mW), which does not cause the effect of photorefractive and more powerful radiation of the second harmonic MLL-100 laser Y: Al garnet (λo = 532 nm, P = 90 mW). Irradiation of crystals radiation 632.8 nm and 532 nm (P = 1 mW) photorefractive effect is absent and there is no disclosure of the photoinduced light scattering indicatrix. In this case, conoscopic paintings reflect the state of structural defects in the crystal in the absence of photorefractive effect. When excited by MLL-100 laser radiation on Y:Al garnet (λo = 532 nm, P = 90 mW) in conoscopic patterns appear as its own crystal defects (defined composition and crystal growth conditions), and defects, induced by laser radiation. These crystals characterized by rather a low photorefractive effect. In crystals with a low effect of photorefractive optical distortions associated with the passage of laser light through the crystal is not "smeared" the strong destruction of the laser beam due to photorefractive effect, and confidently observable.

  14. Observation of bright spatial photorefractive solitons in a planar strontium barium niobate waveguide.

    PubMed

    Kip, D; Wesner, M; Shandarov, V; Moretti, P

    1998-06-15

    We have obtained stationary bright spatial solitons in a planar photorefractive strontium barium niobate waveguide for visible light ranging from 514.5 to 780 nm. Even for larger wavelengths (lambda=1047 nm) strong self-focusing of the beam was observed; however, input power had to be some orders of magnitude higher than for visible light for self-focusing to occur. Furthermore, we found transient self-trapping of red light (lambda=632.8 nm) that corresponds to the formation of bright quasi-steady-state solitons.

  15. Microstructure and defects probed by Raman spectroscopy in lithium niobate crystals and devices

    SciTech Connect

    Fontana, Marc D.; Bourson, Patrice

    2015-12-15

    Raman microprobe applied on LiNbO{sub 3} (LN) crystals and derived materials or devices is shown to be a tool to detect either local variations or changes of the whole structure. Position, width, or intensity of one Raman line can be used as markers of a structural change. Indeed, each Raman line can be assigned to a peculiar ionic motion and is differently sensitive to application of strain, temperature change, and electric field. Some vibrational modes are especially associated to the site of Li ion, or Nb ion, or still oxygen octahedron, so that they can be affected by the introduction of dopant ion on one or another site. Therefore, Raman Spectroscopy (RS) can be used as a site spectroscopy to describe the mechanism of doping incorporation in the LN lattice, allowing the optimization of some linear and non-linear optical properties according to the dopant concentration and substitution site. The composition or the content of non-stoichiometry related defects could be derived from the width of some lines. Any damage or local disorder can be detected by a line broadening. The quality or preservation of the structure after chemical treatment, or laser pulses, can be thus checked. The structure of ion-implanted or proton-exchanged wave-guides and periodically poled lithium niobate as well can be imaged from frequency shift or intensity change of some lines. RS is thus a useful way to control the structure of LN and/or to optimize the preparation parameters and its properties.

  16. Fano resonance-based highly sensitive, compact temperature sensor on thin film lithium niobate.

    PubMed

    Qiu, Wentao; Ndao, Abdoulaye; Vila, Venancio Calero; Salut, Roland; Courjal, Nadège; Baida, Fadi Issam; Bernal, Maria-Pilar

    2016-03-15

    In this Letter, we report a Fano resonance-based highly sensitive and compact temperature sensor fabricated on thin film lithium niobate (TFLN) Suzuki phase lattice (SPL) photonic crystal. The experimental sensitivity is estimated to be 0.77 nm/°C with a photonic crystal size of only 25  μm × 24  μm. This sensitivity is 38 times larger than the intrinsic one of lithium niobate which is 0.02 nm/°C. The demonstrated sharp and high extinction ratio characteristics of the Fano lineshape resonance could be an excellent candidate in developing a high sensitivity temperature sensor, electric field sensor, etc.

  17. Shape manipulation of ion irradiated Ag nanoparticles embedded in lithium niobate

    NASA Astrophysics Data System (ADS)

    Wolf, Steffen; Rensberg, Jura; Johannes, Andreas; Thomae, Rainer; Smit, Frederick; Neveling, Retief; Moodley, Mathew; Bierschenk, Thomas; Rodriguez, Matias; Afra, Boshra; Hasan, Shakeeb Bin; Rockstuhl, Carsten; Ridgway, Mark; Bharuth-Ram, Krish; Ronning, Carsten

    2016-04-01

    Spherical silver nanoparticles were prepared by means of ion beam synthesis in lithium niobate. The embedded nanoparticles were then irradiated with energetic 84Kr and 197Au ions, resulting in different electronic energy losses between 8.1 and 27.5 keV nm-1 in the top layer of the samples. Due to the high electronic energy losses of the irradiating ions, molten ion tracks are formed inside the lithium niobate in which the elongated Ag nanoparticles are formed. This process is strongly dependent on the initial particle size and leads to a broad aspect ratio distribution. Extinction spectra of the samples feature the extinction maximum with shoulders on either side. While the maximum is caused by numerous remaining spherical nanoparticles, the shoulders can be attributed to elongated particles. The latter could be verified by COMSOL simulations. The extinction spectra are thus a superposition of the spectra of all individual particles.

  18. Acoustically determined linear piezoelectric response of lithium niobate up to 1100 V

    SciTech Connect

    Patel, N.; Branch, D. W.; Cular, S.; Schamiloglu, E.

    2014-04-21

    We present a method to measure high voltages using the piezoelectric crystal lithium niobate without using voltage dividers. A 36° Y-X cut lithium niobate crystal was coupled to two acoustic transducers, where direct current voltages were applied from 128–1100 V. The time-of-flight through the crystal was determined to be linearly dependent on the applied voltage. A model was developed to predict the time-delay in response to the applied voltage. The results show a sensitivity of 17 fs/V with a measurement error of 1 fs/V was achievable using this method. The sensitivity of this method can be increased by measuring the acoustic wave after multiple passes through the crystal. This method has many advantages over traditional techniques such as: favorable scalability for larger voltages, ease of use, cost effectiveness, and compactness.

  19. Impact Stress Measurement Using Piezoelectric Probes with PZT and Lithium Niobate Elements

    NASA Astrophysics Data System (ADS)

    Mears, A.; Routley, N. R.; Kendall, P. A.

    2009-12-01

    Previous gas gun experiments using low density foam flyers examined the dynamic response of Dynasen CA-1136 piezoelectric probes having lead zirconate titanate (PZT) elements for impact stresses in the range 0.07 to 0.3 GPa. Recent experiments have extended the dataset down to 0.01 GPa, compared PZT based probes with lithium niobate based probes and compared the measured stresses from manganin gauges with the stresses from the piezoelectric probes. For 0.1 g/cm3 polystyrene and 0.3 g/cm3 polyurethane foams impacting probes with APC 850 PZT elements and generating stresses around 0.1 GPa, the effective piezoelectric charge coefficient was close to three times the PZT manufacturer's value of 400 pC/N. As the impact stress was reduced the coefficient decreased towards 400 pC/N. The measured stresses from the lithium niobate probes were close to the stresses obtained from the manganin gauges.

  20. Ultraviolet laser-induced submicron spatially resolved superhydrophilicity on single crystal lithium niobate surfaces

    SciTech Connect

    Muir, A. C.; Mailis, S.; Eason, R. W.

    2007-05-15

    Lithium niobate crystal surfaces become superhydrophilic after ultraviolet laser irradiation. The crystal surface hydrophilicity, which was assessed by the contact angle of a sessile drop of de-ionized water, was found to undergo a transition from mildly hydrophobic (contact angle {theta}{sub E}{approx_equal}50 degree sign ) to a superhydrophilic state ({theta}{sub E}<5 degree sign ). Patterning of the hydrophilicity at the micron and submicron ranges has been achieved by spatially modulating the illuminating laser beam.

  1. Interdomain region in single-crystal lithium niobate bimorph actuators produced by light annealing

    SciTech Connect

    Kubasov, I. V. Timshina, M. S.; Kiselev, D. A.; Malinkovich, M. D.; Bykov, A. S.; Parkhomenko, Yu. N.

    2015-09-15

    The interdomain region of a bidomain strucrture formed in 127°-cut lithium niobate single crystals using light annealing has been studied by optical and scanning probe microscopies. A periodic subdomain structure on the 180° macrodomain wall is visualized by piezoresponse force microscopy. The piezoresponse signal (polarization) is shown to be a power-law function of the domain width with an exponent n = 0.53.

  2. Development of a new pulsed source for photoacoustic imaging based on aperiodically poled lithium niobate

    PubMed Central

    Yankelevich, Diego; González, J. E.; Cudney, Roger S.; Ríos, Luis A.; Marcu, Laura

    2014-01-01

    We present the development of a source of deep-red radiation for photoacoustic imaging. This source, which is based on two cascaded wavelength conversion processes in aperiodically poled lithium niobate, emits 10 nanosecond pulses of over 500 µJ at 710 nm. Photoacoustic images were obtained from phantoms designed to mimic the optical and acoustic properties of oral tissue. Results indicate this device is a viable source of optical pulses for photoacoustic applications. PMID:24575341

  3. Design of pseudorandom binary sequence generator using lithium-niobate-based Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Choudhary, Kuldeep; Kumar, Santosh

    2017-05-01

    The application of electro-optic effect in lithium-niobate-based Mach-Zehnder interferometer to design a 3-bit optical pseudorandom binary sequence (PRBS) generator has been proposed, which is characterized by its simplicity of generation and stability. The proposed device is optoelectronic in nature. The PBRS generator is immensely applicable for pattern generation, encryption, and coding applications in optical networks. The study is carried out by simulating the proposed device with beam propagation method.

  4. Dependence of effective internal field of congruent lithium niobate on its domain configuration and stability

    SciTech Connect

    Das, Ranjit E-mail: souvik2cat@gmail.com Ghosh, Souvik E-mail: souvik2cat@gmail.com Chakraborty, Rajib E-mail: souvik2cat@gmail.com

    2014-06-28

    Congruent lithium niobate is characterized by its internal field, which arises due to defect clusters within the crystal. Here, it is shown experimentally that this internal field is a function of the molecular configuration in a particular domain and also on the stability of that particular configuration. The measurements of internal field are done using interferometric technique, while the variation of domain configuration is brought about by room temperature high voltage electric field poling.

  5. The asymmetry between the domain walls of periodically poled lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Kong, Yongfa; Xu, Jingjun; Li, Bing; Chen, Shaolin; Huang, Ziheng; Zhang, Ling; Liu, Shiguo; Yan, Wenbo; Liu, Hongde; Xie, Xiang; Shi, Lihong; Li, Xiaochun; Zhang, Guangyin

    2004-12-01

    The domain walls of periodically poled lithium niobate (PPLN) crystals were investigated using Raman spectrum mapping. The periodical changes of Raman shift in several Raman lines along the period of PPLN have been found. The experimental results show that the domain reversal has different degree of affection on its two neighbor regions, which is related to the asymmetry of crystal lattice. This phenomenon can be used to examine the periodical domain reversal of LN non-contacted, non-destructive and easily operated.

  6. Controlled composition modulation in potassium lithium tantalate niobate crystals grown by off-centered TSSG method

    NASA Astrophysics Data System (ADS)

    de Oliveira, C. E. M.; Orr, G.; Axelrold, N.; Agranat, A. J.

    2004-12-01

    Off-centered top-seeded solution growth (TSSG) method is demonstrated as an effective and simple way to generate controlled composition modulation in potassium lithium tantalate niobate (KLTN) single crystals. The changes in concentration were measured by differential interference contrast (DIC) microscopy. Large length with periodic modulations ranging from 1 to 5 μm in period was grown along a KLTN sample with period dispersion lower than 2%.

  7. Lithium concentration profiles in APE:LiNbO3 optical waveguides

    NASA Astrophysics Data System (ADS)

    Nekvindova, Pavla; Spirkova-Hradilova, Jarmila; Vacik, Jiri; Cervena, Jarmila; Schroefel, Josef

    1999-12-01

    Lithium concentration depth profiles of proton exchanged (PE) and annealed proton exchanged (APE) lithium niobate optical waveguides were monitored by neutron depth profiling (NDP) for a large variety of the samples. Results of the measurements are related to the corresponding ne depth profiles as measure by the standard prisms coupling method. It was found that cLi depth profiles of the PE waveguides fabricated in X- and Z-cuts using the same fabrication conditions are almost identical indicating thus very similar extend of H+ $ARLR Li+ exchange reaction. The maximal depths of the exchanged layers were 3 micrometers . The following annealing causes a massive transport of lithium atoms towards the exchanged regions of the as- exchanged samples which is differs in the both types of the cuts. The Li-transport in the X-cuts seems to be hampered by a barrier formed by the larger amount of in-diffused interstitial hydrogen in the X-cuts, which results in a more-less step-like profiles of the X-cuts parameters. A formula relating nc to CLi values for the APE waveguides is also presented.

  8. Volumetric integration of photorefractive micromodifications in lithium niobate with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Paipulas, D.; Mizeikis, V.; Purlys, V.; ČerkauskaitÄ--, A.; Juodkazis, S.

    2015-03-01

    After the discovery that focused laser pulse is capable to locally change material's refractive index it became possible to integrate various photonic devices or data directly into the volume of transparent material, usually with conventional Direct Laser Writing (DLW) techniques. Many different photonic devices, passive or active, integrated in different materials were demonstrated. In majority of cased the change in refractive index comes from rearrangement (damage) of materials' lattice and are permanent. Metastable (reversible) modification can be beneficial for some applications and these could be realized in photorefractive crystals such as lithium niobate. While photorefractive data recording is a well studied process in holographic applications, the photorefractive induction via femtosecond laser pulses is scarcely investigated. in this work we demonstrate the possibility to form discrete regions for homogeneously-altered refractive index in bulk of pure and iron doped lithium niobate crystals using femtosecond DLW technique. We shoe that non-linear free charge generation and charge separation caused by the bulk photovoltaic effect are the main contributing factors to the change in refractive index. Moreover, femtosecond pulse induced refractive index change can be by an order of magnitude higher than values reached with longer laser pulses. Femtosecond DLW opens opportunities for precise control of topological charge separation in lithium niobate crystals in volume and in micrometer scale. Various examples as well as strategies to control and manipulate refractive index change is presented and discussed.

  9. Graphene Based Surface Plasmon Polariton Modulator Controlled by Ferroelectric Domains in Lithium Niobate

    PubMed Central

    Wang, Hao; Zhao, Hua; Hu, Guangwei; Li, Siren; Su, Hang; Zhang, Jingwen

    2015-01-01

    We proposed a ferroelectric domain controlled graphene based surface plasmon polariton modulator. Ferroelectricity-induced electronic and optical property tuning of graphene by domain in lithium niobate was theoretically investigated considering both interband and intraband contributions of surface conductivity. With the corrected Sellmeier equation of lithium niobate, the propagation of transverse magnetic mode surface plasmon polaritons in an air/graphene/lithium niobate structure was studied when monolayer graphene was tuned by down polarization direction ferroelectric domain with different polarization levels. The length of the ferroelectric domain was optimized to be 90 nm for a wavelength of 5.0 μm with signal extinction per unit 14.7 dB/μm, modulation depth 474.1 dB/μm and figure of merit 32.5. This work may promote the study of highly efficient modulators and other ultra-compact nonvolatile electronic and photonic devices in which two-dimensional materials and ferroelectric materials are combined. PMID:26657622

  10. III-nitride integration on ferroelectric materials of lithium niobate by molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Namkoong, Gon; Lee, Kyoung-Keun; Madison, Shannon M.; Henderson, Walter; Ralph, Stephen E.; Doolittle, W. Alan

    2005-10-01

    Integration of III-nitride electrical devices on the ferroelectric material lithium niobate (LiNbO3) has been demonstrated. As a ferroelectric material, lithium niobate has a polarization which may provide excellent control of the polarity of III-nitrides. However, while high temperature, 1000°C, thermal treatments produce atomically smooth surfaces, improving adhesion of GaN epitaxial layers on lithium niobate, repolarization of the substrate in local domains occurs. These effects result in multi domains of mixed polarization in LiNbO3, producing inversion domains in subsequent GaN epilayers. However, it is found that AlN buffer layers suppress inversion domains of III-nitrides. Therefore, two-dimensional electron gases in AlGaN /GaN heterojunction structures are obtained. Herein, the demonstration of the monolithic integration of high power devices with ferroelectric materials presents possibilities to control LiNbO3 modulators on compact optoelectronic/electronic chips.

  11. III-nitride integration on ferroelectric materials of lithium niobate by molecular beam epitaxy

    SciTech Connect

    Namkoong, Gon; Lee, Kyoung-Keun; Madison, Shannon M.; Henderson, Walter; Ralph, Stephen E.; Doolittle, W. Alan

    2005-10-24

    Integration of III-nitride electrical devices on the ferroelectric material lithium niobate (LiNbO{sub 3}) has been demonstrated. As a ferroelectric material, lithium niobate has a polarization which may provide excellent control of the polarity of III-nitrides. However, while high temperature, 1000 deg. C, thermal treatments produce atomically smooth surfaces, improving adhesion of GaN epitaxial layers on lithium niobate, repolarization of the substrate in local domains occurs. These effects result in multi domains of mixed polarization in LiNbO{sub 3}, producing inversion domains in subsequent GaN epilayers. However, it is found that AlN buffer layers suppress inversion domains of III-nitrides. Therefore, two-dimensional electron gases in AlGaN/GaN heterojunction structures are obtained. Herein, the demonstration of the monolithic integration of high power devices with ferroelectric materials presents possibilities to control LiNbO{sub 3} modulators on compact optoelectronic/electronic chips.

  12. Laser excitation of transversal and longitudinal polar modes in lithium niobate and tantalate crystals

    NASA Astrophysics Data System (ADS)

    Gorelik, Vladimir S.; Sidorov, Nikolay V.; Sverbil, Pavel P.; Vodchits, Alexander I.

    2016-11-01

    The excitation of longitudinal and transversal electromagnetic waves in lithium niobate and tantalate crystals is of interest for establish the conditions of coherent longitudinal and transversal waves generation in media and in vacuum. In this paper the results of laser excitation of transversal and longitudinal polar modes in these crystals are presented. We have measured spontaneous Raman spectra of lithium niobate and tantalate crystals in 0° (forward), 90°, and 180° (backward) scattering geometries. We have observed Raman peaks, related to fundamental transversal and longitudinal A1(Z) and E((X,Y) polar optical modes. In addition, there were pseudoscalar symmetry A2 peaks, forbidden by selection rules in Raman spectra for point group C3v. This was explained by reducing of the point group from C3v to C3 due to the presence of impurities in real crystals. Besides, the acoustic biphonon at low frequency has been observed. High intensity of spontaneous A1(Z)LO and A1(Z)TO Raman satellites gives the opportunity for generation of coherent longitudinal and transversal terahertz waves in lithium niobate and tantalate crystals with the help of Stimulated Raman Scattering under using high-power laser pumping. The presence of pseudoscalar and biphonons mode in low frequency region results in the strong interaction with fundamental soft mode and sharp central peak near the phase transition.

  13. When Halides Come to Lithium Niobate Nanopowders Purity and Morphology Assistance.

    PubMed

    Lamouroux, Emmanuel; Badie, Laurent; Miska, Patrice; Fort, Yves

    2016-03-07

    The preparation of pure lithium niobate nanopowders was carried out by a matrix-mediated synthesis approach. Lithium hydroxide and niobium pentachloride were used as precursors. The influence of the chemical environment was studied by adding lithium halide (LiCl or LiBr). After thermal treatment of the precursor mixture at 550 °C for 30 min, the morphology of the products was obtained from transmission electron microscopy and dynamic light scattering, whereas the crystallinity and phase purity were characterized by X-ray diffraction and UV-visible and Raman spectroscopies. Our results point out that the chemical environment during lithium niobate formation at 550 °C influences the final morphology. Moreover, direct and indirect band-gap energies have been determined from UV-visible spectroscopy. Their values for the direct-band-gap energies range from 3.97 to 4.36 eV with a slight dependence on the Li/Nb ratio, whereas for the indirect-band-gap energies, the value appears to be independent of this ratio and is 3.64 eV. No dependence of the band-gap energies on the average crystallite and nanoparticle sizes is observed.

  14. 1-3 connectivity composite material made from lithium niobate and cement for ultrasonic condition monitoring at elevated temperatures.

    PubMed

    Shepherd, G; Cochran, A; Kirk, K J; McNab, A

    2002-05-01

    We have designed, manufactured and tested a piezoelectric composite material to operate at temperatures above 400 degrees C. The material is a 1-3 connectivity composite with pillars of Z-cut lithium niobate in a matrix of alumina cement. The composite material produced shorter pulses than a monolithic plate of lithium niobate and remained intact upon cooling. Results are presented from room temperature and high temperature testing. This material could be bonded permanently to a test object, making it possible to carry out condition monitoring over an extended period. A new excitation method was also developed to enable remote switching between array elements.

  15. Simultaneous stimulated Raman scattering and second harmonic generation in periodically poled lithium niobate

    NASA Astrophysics Data System (ADS)

    McConnell, Gail; Ferguson, Allister I.

    2005-03-01

    Simultaneous stimulated Raman scattering (SRS) and second harmonic generation (SHG) are demonstrated in periodically poled lithium niobate (PPLN). Using a simple single-pass geometry, conversion efficiencies of up to 12% and 19% were observed for the SRS and SHG processes respectively. By changing the PPLN period interacting with the photonic crystal fibre based pump source and varying the PPLN temperature, the SHG signal was measured to be tunable from λ =584 nm to λ =679 nm. The SRS output spectrum was measured at λ=1583 nm, with a spectral full-width at half-maximum of λ =85 nm.

  16. Change in the structural imperfection of lithium niobate crystals doped with zinc

    SciTech Connect

    Litvinova, V. A. Litvinova, M. N.

    2015-01-15

    The changes in the degree of structural imperfection of lithium niobate (LiNbO{sub 3}) single crystals with an increase in the Li content and doping with zinc (to 1 wt %) have been investigated by the nonlinear optics methods and Raman spectroscopy. The conversion of broadband IR radiation in LiNbO{sub 3} crystals under noncritical (90°) phase-matching condition with vector interactions implemented is investigated. It is shown that the conversion efficiency, spectral width, and the position of maximum in the converted radiation spectrum depend on the ratio R = Li/Nb in LiNbO{sub 3} crystal and the impurity concentration.

  17. Aperture scaling effects with monolithic periodically poled lithium niobate optical parametric oscillators and generators.

    PubMed

    Missey, M; Dominic, V; Powers, P; Schepler, K L

    2000-02-15

    We used elliptical beams to demonstrate aperture scaling effects in nanosecond single-grating and multigrating periodically poled lithium niobate (PPLN) monolithic optical parametric oscillators and generators. Increasing the cavity Fresnel number in single-grating crystals broadened both the beam divergence and the spectral bandwidth. Both effects are explained in terms of the phase-matching geometry. These effects are suppressed when a multigrating PPLN crystal is used because the individual gratings provide small effective subapertures. A flood-pumped multigrating optical parametric generator displayed a low output beam divergence and contained 19 pairs of signal and idler frequencies.

  18. Fabrication of Pattern Poled Lithium Niobate Film and its Nonlinear Optical Applications

    NASA Astrophysics Data System (ADS)

    Xu, M.; Wang, M.; Chen, Z.; Tang, J.; Shao, G.; Ming, Y.; Cui, G.; Lu, Y.

    2017-06-01

    We develop an approach to fabricate arbitrary ferroelectric domain patterns on lithium niobate film (30-50 μm thick) by applying a structured external field at room temperature. The fabricating method can be operated easily to reach 1 μm linewidth resolution. The ferroelectric domain inversion is stable and uniform. Nonlinear diffraction is generated when the fundamental wave pumps to film. Various nonlinear wavefronts are obtained such as the frequency converted optical vortex beam. A nonlinear holographic concept is proposed to explain the physical phenomena and guide the corresponding domain design. The applications in optical field manipulation and novel photonic states generation are discussed.

  19. Microraman and Photorefractivity Study of Hafnium-Doped Lithium Niobate Crystals

    NASA Astrophysics Data System (ADS)

    Galinetto, Pietro; Rossella, Francesco; Minzioni, Paolo; Razzari, Luca; Cristiani, Ilaria; Degiorgio, Vittorio; Kokanyan, Edvard P.

    We present an investigation of the properties of HfO2-doped lithium niobate crystals, in view of their possible utilization as low-photorefractivity crystals for wavelength converters operating at room temperature. MicroRaman measurements indicate that the linewidth of a specific mode can be used as a local indicator of crystal composition, and show that the grown crystals present very good uniformity. The mechanism by which the photorefractivity is strongly reduced when the HfO2 concentration is above 4 mol% is studied by combining measurements of birefringence variation, under green-light illumination, with electrical phototransport data.

  20. Ferroelectric domain gratings and Barkhausen spikes in potassium lithium tantalate niobate

    SciTech Connect

    Tong, X.; Yariv, A.; Zhang, M.; Agranat, A.J.; Hofmeister, R.; Leyva, V.

    1997-04-01

    The observation of Barkhausen current spikes during the recording of volume phase holograms in potassium lithium tantalate niobate is reported on. These spikes are due to the ferroelectric domain reversal induced by photorefractive space charge fields. Both {open_quotes}small{close_quotes} (1 nA) and {open_quotes}large{close_quotes} (100 nA) spikes are observed, which correspond to micro and macro domain reversal, respectively. The diffraction efficiency can change as much as 50{percent} during a single macrodomain switching. {copyright} {ital 1997 American Institute of Physics.}

  1. Micro-buried spiral zone plate in a lithium niobate crystal

    NASA Astrophysics Data System (ADS)

    Tian, Zhen-Nan; Hua, Jian-Guan; Hao, Juan; Yu, Yan-Hao; Chen, Qi-Dai; Sun, Hong-Bo

    2017-01-01

    We present a micro-buried spiral zone plate (MBSZP) in the lithium niobate crystal fabricated with femtosecond laser direct writing technology. The microstructures of the MBSZP are buried under the surface of the crystal, which ensures the stability of the optical performance in various refractive index environments. The optical performances of imaging and focusing capabilities were demonstrated. In addition, the experiment showed good agreement with simulation results based on the optical wave propagation method. This novel optical element will have important applications in multistate information encoding, optical manipulation, quantum communication, and computation, especially in high integration, contact coupling, and variable refractive index environments.

  2. Topographic investigation of ferroelectric domain structures in periodically-poled lithium niobate crystals by a profilometer

    SciTech Connect

    Bazzan, M.; Argiolas, N.; Bernardi, A.; Mazzoldi, P.; Sada, C

    2003-10-15

    A topographic investigation of periodically poled lithium niobate (PPLN) crystals was performed by recording a map of the crystal surface after a selective etching process using a standard profilometer. A procedure to correct for the systematic error introduced by the finite size of the tip is discussed in detail so that the width of ferroelectric domains can be mapped with an estimated tolerance of about 3% along the whole length of the sample. The method is applied to a PPLN structure obtained by the Czochralski off-center technique.

  3. Mode analysis of photonic crystal L3 cavities in self-suspended lithium niobate membranes

    SciTech Connect

    Diziain, Séverine Geiss, Reinhard; Zilk, Matthias; Schrempel, Frank; Kley, Ernst-Bernhard; Pertsch, Thomas; Tünnermann, Andreas

    2013-12-16

    We report on a multimodal analysis of photonic crystal L3 cavities milled in lithium niobate free-standing membranes. The classical L3 cavity geometry is compared to an L3 cavity containing a second lattice superimposed on the primary one. Those two different geometries are investigated in terms of vertical radiation and quality (Q) factor for each mode of the cavities. Depending on the cavity geometry, some modes undergo an enhancement of their vertical radiation into small angles while other modes experience a higher Q factor. Experimental characterizations are corroborated by three-dimensional finite difference time domain simulations.

  4. Compensating thermal drift of hybrid silicon and lithium niobate ring resonances.

    PubMed

    Chen, Li; Wood, Michael G; Reano, Ronald M

    2015-04-01

    We present low-power compensation of thermal drift of resonance wavelengths in hybrid silicon and lithium niobate ring resonators based on the linear electro-optic effect. Fabricated devices demonstrate a resonance wavelength tunability of 12.5  pm/V and a tuning range of 1 nm. A capacitive geometry and low thermal sensitivity result in the compensation of 17°C of temperature variation using tuning powers at sub-nanowatt levels. The method establishes a route for stabilizing high-quality factor resonators in chip-scale integrated photonics subject to temperature variations.

  5. Investigation of spatially nonuniform nonlinear response of a lithium niobate crystal sample at low light intensity

    NASA Astrophysics Data System (ADS)

    Dmitriev, E.; Beresina, E.; Krad`ko, V.; Ryabchenok, V.; Perin, A.; Shandarov, V.

    2016-08-01

    The spatial distribution of nonlinear optical response over a bulk of lithium niobate sample is experimentally studied through the distortions of the two-dimensional light beam intensity patterns at the sample output surface caused by the beam spatial self-action. The compensation of these distortions and the linear light beam divergence by means of the pyroelectric effect contribution into the nonlinear optical response of the crystal are also studied. The results obtained for the light wavelength of 532 nm and beam waist diameter of 13 μm demonstrate the partial or total compensation of the beam divergence depending on light power and a temperature increase at the sample heating.

  6. Broadband characterization of congruent lithium niobate from mHz to optical frequencies

    NASA Astrophysics Data System (ADS)

    Cochard, Charlotte; Spielmann, Thiemo; Bahlawane, Naoufal; Halpin, Alexei; Granzow, Torsten

    2017-09-01

    Lithium niobate (LiNbO3) is a well known uniaxial ferroelectric material. Using impedance measurement, quasi-optical free-space characterization, THz time domain spectroscopy (THz-TDS) and ellipsometry, its dielectric permittivity/refractive index was characterized depending on the crystal orientation over a broad frequency range: 1 mHz to 1 PHz (λ = 300 nm). Three different frequency ranges, separated by well identified resonances, are observed: low frequency ‘free-piezoelectric’ response, intermediate frequency ‘clamped-ionic’ response and high frequency ‘electronic’ response. These features are discussed with an emphasis on the role of the crystallographic structure and piezoelectric response.

  7. Nonlinear multiwavelength conversion based on an aperiodic optical superlattice in lithium niobate.

    PubMed

    Lee, Y W; Fan, F C; Huang, Y C; Gu, B Y; Dong, B Z; Chou, M H

    2002-12-15

    We have demonstrated what is to our knowledge the first successful achievement of multiwavelength conversion in an aperiodic optical superlattice (AOS) lithium niobate crystal with equalized gain. The two AOS devices in our experiment, numerically synthesized from 2857 crystal blocks with a unit block thickness of 3.5 microm, have fundamental wavelengths of 1540 and 1545 nm for double-wavelength second-harmonic generation (SHG) and of 1540, 1545, and 1553 nm for triple-wavelength SHG at 50 degrees C. Our experiment and simulation show that the output spectrum of an AOS wavelength converter is fairly insensitive to typical fabrication errors.

  8. Refractive index changes in lithium niobate crystals by high-energy particle radiation

    SciTech Connect

    Peithmann, Konrad; Zamani-Meymian, Mohammad-Reza; Haaks, Matz; Maier, Karl; Andreas, Birk; Breunig, Ingo

    2006-10-15

    Irradiation of lithium niobate crystals with 41 MeV {sup 3}He ions causes strong changes of the ordinary and extraordinary refractive indexes. We present a detailed study of this effect. Small fluence of irradiation already yields refractive index changes about 5x10{sup -4}; the highest values reach 3x10{sup -3}. These index modulations are stable up to 100 degree sign C and can be erased thermally, for which temperatures up to 500 degree sign C are required. A direct correlation between the refractive index changes and the produced lattice vacancies is found.

  9. Fabrication of high-Q lithium niobate microresonators using femtosecond laser micromachining

    PubMed Central

    Lin, Jintian; Xu, Yingxin; Fang, Zhiwei; Wang, Min; Song, Jiangxin; Wang, Nengwen; Qiao, Lingling; Fang, Wei; Cheng, Ya

    2015-01-01

    We report on fabrication of high-Q lithium niobate (LN) whispering-gallery-mode (WGM) microresonators suspended on silica pedestals by femtosecond laser direct writing followed by focused ion beam (FIB) milling. The micrometer-scale (diameter ~82 μm) LN resonator possesses a Q factor of ~2.5 × 105 around 1550 nm wavelength. The combination of femtosecond laser direct writing with FIB enables high-efficiency, high-precision nanofabrication of high-Q crystalline microresonators. PMID:25627294

  10. Paramagnetic defects as probes for the study of ferroelastic phase transition in lithium niobate and lithium tantalate under high pressure

    NASA Astrophysics Data System (ADS)

    Malovichko, G.; Grachev, V.; Andreev, V.; Nachal'Naya, T.

    It was found by optical polarization microscopy and the EPR study that lithium niobate and tantalate crystals undergo irreversible lattice changes under anisotropic hydrostatic compression. Regions having different cell orientations were registered. The observed changes were explained in terms of "strain switching" of ferroelastic domains. Possible sequence of phase transitions in these crystals (Pm3m<->R (3) over bar3 c<->R 3 c) and the symmetry of the condensed soft modes ( R-25 and Gamma(15) , correspondingly) were obtained by the analysis of the Gibbs free energy under external pressure.

  11. Lithium niobate-based integrated optic chip utilizing digital electrode layout for use in a miniature fiber optic rate sensor

    NASA Astrophysics Data System (ADS)

    Ner, Manjeet S.; Kemmler, Manfred W.; Spahlinger, Guenter

    1996-11-01

    This paper describes to the best of our knowledge the first implementation of a Lithium Niobate based 8 bit electroded integrated optic waveguide fiber optic gyro chip referred here to as 'Digi-MIOC', which has been used in a Sagnac effect exploiting micro fiber optic rate sensor ((mu) -FORS) developed by LITEF. The paper highlights various features of a Digi-MIOC, such as design philosophy, fabrication aspects, and test procedures to evaluate static and dynamic characteristics of the electro-optic parameters. As a consequence of this work, it has been possible for LITEF to cost effectively mass produce Digi-MIOCs. When used in closed loop operation, the Digi-MIOC forms the key optical component of a (mu) -FORS to aid the required optical-to- electrical signal processing to give linear output for input rates of rotation. Various test results and features of LITEF's (mu) -FORS, such as small size, large rotation rate measurement potential, low drive power and high reliability are also highlighted.

  12. Read-write holographic memory with iron-doped lithium niobate

    NASA Technical Reports Server (NTRS)

    Alphonse, G. A.; Phillips, W.

    1975-01-01

    The response of iron doped lithium niobate under conditions corresponding to hologram storage and retrieval is described, and the material's characteristics are discussed. The optical sensitivity can be improved by heavy chemical reduction of lightly doped crystals such that most of the iron is in the divalent state, the remaining part being trivalent. The best reduction process found to be reproducible so far is the anneal of the doped crystal in the presence of a salt such as lithium carbonate. It is shown by analysis and simulation that a page-oriented read-write holographic memory with 1,000 bits per page would have a cycle time of about 60 ms and a signal-to-noise ratio of 27 db. This cycle time, although still too long for a practical system, represents an improvement of two orders of magnitude over that of previous laboratory prototypes using different storage media.

  13. Solid sampling determination of magnesium in lithium niobate crystals by graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Dravecz, Gabriella; Laczai, Nikoletta; Hajdara, Ivett; Bencs, László

    2016-12-01

    The vaporization/atomization processes of Mg in high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS) were investigated by evaporating solid (powder) samples of lithium niobate (LiNbO3) optical single crystals doped with various amounts of Mg in a transversally heated graphite atomizer (THGA). Optimal analytical conditions were attained by using the Mg I 215.4353 nm secondary spectral line. An optimal pyrolysis temperature of 1500 °C was found for Mg, while the compromise atomization temperature in THGAs (2400 °C) was applied for analyte vaporization. The calibration was performed against solid (powered) lithium niobate crystal standards. The standards were prepared with exactly known Mg content via solid state fusion of the oxide components of the matrix and analyte. The correlation coefficient (R value) of the linear calibration was not worse than 0.9992. The calibration curves were linear in the dopant concentration range of interest (0.74-7.25 mg/g Mg), when dosing 3-10 mg of the powder samples into the graphite sample insertion boats. The Mg content of the studied 19 samples was in the range of 1.69-4.13 mg/g. The precision of the method was better than 6.3%. The accuracy of the results was verified by means of flame atomic absorption spectrometry with solution sample introduction after digestion of several crystal samples.

  14. Stopping power of 1H and 4He in lithium niobate

    NASA Astrophysics Data System (ADS)

    Barradas, N. P.; Marques, J. G.; Alves, E.

    2014-08-01

    Lithium niobate is an important material for applications in bulk optoelectronics and integrated optics devices. Ion beam analysis methods are often used to study this material. However, to our knowledge a single study has been presented in 1996 on measurement of stopping powers in LiNbO3 at velocities usual in ion beam analysis, for protons and deuterons near the stopping power maximum. The results were 15% lower than the values calculated from the elemental Li, Nb and O stopping powers then available together with the Bragg rule. In practice, all ion beam analysis studies of LiNbO3 still use the Bragg rule. We have used a bulk method, previously developed by us and applied successfully to other systems, to determine experimentally the stopping power of lithium niobate for 1H and 4He ions in the energy range 0.3-2.3 MeV. The results of our measurements and bulk method analysis are presented and discussed in the context of currently available stopping power calculations.

  15. Ultrafast optical reversible double Feynman logic gate using electro-optic effect in lithium-niobate based Mach Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Chauhan, Chanderkanta; Bedi, Amna; Kumar, Santosh

    2017-02-01

    In this ultra fast computing era power optimization is a major technological challenge that requires new computing paradigms. Conservative and reversible logic opens up the possibility of ultralow power computing. In this paper, basic reversible logic gate (double Feynman gate) using the lithium-niobate based Mach-Zehnder interferometer is proposed. The results are verified using beam propagation method and MATLAB simulations.

  16. Investigation of semiconductor clad optical waveguides

    NASA Technical Reports Server (NTRS)

    Batchman, T. E.; Carson, R. F.

    1985-01-01

    A variety of techniques have been proposed for fabricating integrated optical devices using semiconductors, lithium niobate, and glasses as waveguides and substrates. The use of glass waveguides and their interaction with thin semiconductor cladding layers was studied. Though the interactions of these multilayer waveguide structures have been analyzed here using glass, they may be applicable to other types of materials as well. The primary reason for using glass is that it provides a simple, inexpensive way to construct waveguides and devices.

  17. Lithium niobate miniature lasers and single-crystal fibers

    SciTech Connect

    Cordova-Plaza, A.

    1988-01-01

    LiNbO{sub 3} is a widely used optical material because of its excellent electro-optic and nonlinear properties. By doping LiNbO{sub 3} with an active ion such as Nd, laser oscillation and amplification are added to the panoply of LiNbO{sub 3} device possibilities. Furthermore, by providing LiNbO{sub 3} devices with the waveguide confinement of single-crystal fibers, their performance can be significantly improved. Chapter 1 introduces the subject. Chapter 2 is devoted to miniature continuous-wave Nd:MgO:LiNbO{sub 3} lasers. Important results are the first demonstration of room-temperature, true continuous-wave laser oscillation in Nd-doped LiNbO{sub 3} and the first demonstration of diode-pumped laser action in this material. The Nd:MgO:LiNbO{sub 3} lasers exhibited pump power thresholds (1.9 mW) and slope efficiencies (45%) that are among the state-of-the-art in solid state lasers. Chapter 2 also contains a detailed study on photoconductivity. It explains how the addition of MgO eliminates photorefractive damage. Chapter 3 studies Q-switched laser operation in Nd:MgO:LiNbO{sub 3}. Q-switching consists of generating very intense, nanosecond pulses by rapidly switching the cavity loss.

  18. The H+ related defects involved in domain reversal for both near-stoichiometric and heavily Mg-doped lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Yan, W.; Kong, Y.; Shi, L.; Yao, J.; Chen, S.; Sun, L.; Zhao, D.; Xu, J.; Zhang, G.

    2005-02-01

    Domain reversal was performed on both near-stoichiometric and heavily Mg-doped lithium niobate crystals. H+ related defect structures in these two types of crystals were studied through the infrared absorption spectra. It is found that the intensity of some decomposed peaks of absorption band change apparently during domain reversal for near-stoichiometric lithium niobate crystals but not for heavily Mg-doped lithium niobate crystals. According to these experimental results, distinct models about H+ related defect structure in LiNbO3 lattice were supposed for them. Nb4+Li and Mg3-Nb were considered as the centers of H+ related defect complex for near-stoichiometric and heavily Mg-doped lithium niobate crystals respectively. Different behavior of them was used to explain the difference of infrared absorption spectra during domain reversal between two types of crystals.

  19. Absorption measurement of a 50-mm-Long periodically poled lithium niobate optical parametric oscillator pumped at 1064 nm by a Nd: YAG laser

    NASA Astrophysics Data System (ADS)

    Du, S.; Kaneda, Y.; Yarborough, M.

    2008-08-01

    We measured the absorption of different periodically poled lithium niobate crystals when different wavelength beams come through them. The choice of a periodically poled lithium niobate crystal is utilized by a singly resonant oscillator to efficiently generate 3800-nm light when it is pumped by a 1064-nm laser and to generate the 2600-nm signal, and, then, injection seeded at 1550 nm. The temperature-tuning curve and idler output power of the chosen crystal are measured.

  20. Local Lattice Structure and Dopant Occupancy of Doped Lithium Niobate Crystals

    NASA Astrophysics Data System (ADS)

    Zhang, Zhigang; Xue, Dongfeng

    We present a systematic study of the local distortions produced upon doping metal ions to lithium niobate (LiNbO3, LN) single crystals. The impurity bond length can be predicted by a radial force constant model, when the dopant ions substitute for Li+ or Nb5+ ions in the LN crystallographic frame. From the viewpoint of constituent chemical bonds, the lattice energy can be described as the function of bond valence on the basis of Born-Haber cycle for the formation of an ionic oxide MmOn. The dopant occupancy in the LN matrix can be determined by comparing the deviation of its lattice energy in different locations at both Li+ and Nb5+ sites, on the basis of the bond length relaxation of impurity ions, which can agree well with the experiment results. The effect of impurity ions on the property modification of LN crystals is also discussed according to our calculated results.

  1. Charge and topography patterned lithium niobate provides physical cues to fluidically isolated cortical axons

    NASA Astrophysics Data System (ADS)

    Kilinc, D.; Blasiak, A.; Baghban, M. A.; Carville, N. C.; Al-Adli, A.; Al-Shammari, R. M.; Rice, J. H.; Lee, G. U.; Gallo, K.; Rodriguez, B. J.

    2017-01-01

    In vitro devices that combine chemotactic and physical cues are needed for understanding how cells integrate different stimuli. We explored the suitability of lithium niobate (LiNbO3), a transparent ferroelectric material that can be patterned with electrical charge domains and micro/nanotopography, as a neural substrate. On flat LiNbO3 z-surfaces with periodically alternating charge domains, cortical axons are partially aligned with domain boundaries. On submicron-deep etched trenches, neurites are aligned with the edges of the topographical features. Finally, we bonded a bicompartmental microfluidic chip to LiNbO3 surfaces patterned by etching, to create isolated axon microenvironments with predefined topographical cues. LiNbO3 is shown to be an emerging neuron culture substrate with tunable electrical and topographical properties that can be integrated with microfluidic devices, suitable for studying axon growth and guidance mechanisms under combined topographical/chemical stimuli.

  2. A computer study and photoelectric property analysis of potassium-doped lithium niobate single crystals.

    PubMed

    Wang, Wei; Wang, Rui; Zhang, Wen; Xing, Lili; Xu, Yanling; Wu, Xiaohong

    2013-09-14

    First-principles theory was used to design a potassium-doped lithium niobate single crystal. The structural, electronic, optical and ferroelectric properties of the potassium-doped LiNbO3 single crystal model have been investigated using a generalized gradient approximation within density functional theory. It was found that substitution with potassium drastically changed the optical and electronic nature of the crystal and that the band gap slightly decreases. A series of LiNbO3 single crystals doped with x mol% K (x = 0, 3, 6, 9, 12 mol%) were successfully grown using the Czochralski method. The crystals were characterized using powder X-ray diffraction, UV-vis-infrared absorption spectroscopy and a ferroelectric property test. The experimental test results were consistent with the calculated predictions.

  3. Frequency-agile kilohertz repetition-rate optical parametric oscillator based on periodically poled lithium niobate

    SciTech Connect

    Yang, S.T.; Velsko, S.P.

    1999-02-01

    We report kilohertz repetition-rate pulse-to-pulse wavelength tuning from 3.22 to 3.7 {mu}m in a periodically poled lithium niobate (PPLN) optical parametric oscillator (OPO). Rapid tuning over 400thinspcm{sup {minus}1} with random wavelength accessibility is achieved by rotation of the pump beam angle by no more than 24thinspthinspmrad in the PPLN crystal by use of an acousto-optic beam deflector. Over the entire tuning range, a near-transform-limited OPO bandwidth can be obtained by means of injection seeding with a single-frequency 1.5-{mu}m laser diode. The frequency agility, high repetition rate, and narrow bandwidth of this mid-IR PPLN OPO make it well suited as a lidar transmitter source. {copyright} {ital 1999} {ital Optical Society of America}

  4. Frequency-agile kilohertz repetition-rate optical parametric oscillator based on periodically poled lithium niobate.

    PubMed

    Yang, S T; Velsko, S P

    1999-02-01

    We report kilohertz repetition-rate pulse-to-pulse wavelength tuning from 3.22 to 3.7 mum in a periodically poled lithium niobate (PPLN) optical parametric oscillator (OPO). Rapid tuning over 400 cm(-1) with random wavelength accessibility is achieved by rotation of the pump beam angle by no more than 24 mrad in the PPLN crystal by use of an acousto-optic beam deflector. Over the entire tuning range, a near-transform-limited OPO bandwidth can be obtained by means of injection seeding with a single-frequency 1.5-mum laser diode. The frequency agility, high repetition rate, and narrow bandwidth of this mid-IR PPLN OPO make it well suited as a lidar transmitter source.

  5. Low-temperature anodic bonding using thin films of lithium-niobate-phosphate glass

    NASA Astrophysics Data System (ADS)

    Woetzel, S.; Kessler, E.; Diegel, M.; Schultze, V.; Meyer, H.-G.

    2014-09-01

    This paper reports on the investigation of a low-temperature anodic bonding process with layers of a lithium-niobate-phosphate glass on chip level. The glass layers are deposited by means of rf sputtering. The applied glass is characterised by its high ion conductivity, enabling anodic bonding at room temperature. Results of the optimisation process concerning the intrinsic stress of the glass layers and the thermal exposure of the substrates through the deposition process are presented. The stoichiometry of the glass layers is verified through Rutherford backscattering spectroscopy (RBS). The bonding strength is measured by tensile tests. Microfabricated atomic vapour cells are used for hermeticity tests of the bonding by absorption measurements of the caesium D1 line.

  6. The photorefractive characteristics of bismuth-oxide doped lithium niobate crystals

    SciTech Connect

    Zheng, Dahuai; Yao, Jiaying; Kong, Yongfa; Liu, Shiguo; Zhang, Ling; Chen, Shaolin; Xu, Jingjun

    2015-01-15

    Bismuth-doped lithium niobate (LN:Bi) crystals were grown by Czochralski method and their optical damage resistance, photorefraction, absorption spectra, and defect energy levels were investigated. The experimental results indicate that the photorefractive properties of LN:Bi were enhanced as compared with congruent one, the photorefractive response time was greatly shortened, the photorefractive sensitivity was increased, and the diffraction efficiency of near-stoichiometric LN:Bi (SLN:Bi) reached 31.72% and 49.08% at 532 nm and 488 nm laser, respectively (light intensity of 400 mW/cm{sup 2}). An absorption peak at about 350 nm was observed in the absorption spectrum of LN:Bi. And the defect energy levels simulation indicates new defect levels appear in the forbidden gap of LN:Bi crystals. Therefore bismuth can act as photorefractive centers in LN crystals.

  7. The photorefractive characteristics of bismuth-oxide doped lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Zheng, Dahuai; Kong, Yongfa; Liu, Shiguo; Yao, Jiaying; Zhang, Ling; Chen, Shaolin; Xu, Jingjun

    2015-01-01

    Bismuth-doped lithium niobate (LN:Bi) crystals were grown by Czochralski method and their optical damage resistance, photorefraction, absorption spectra, and defect energy levels were investigated. The experimental results indicate that the photorefractive properties of LN:Bi were enhanced as compared with congruent one, the photorefractive response time was greatly shortened, the photorefractive sensitivity was increased, and the diffraction efficiency of near-stoichiometric LN:Bi (SLN:Bi) reached 31.72% and 49.08% at 532 nm and 488 nm laser, respectively (light intensity of 400 mW/cm2). An absorption peak at about 350 nm was observed in the absorption spectrum of LN:Bi. And the defect energy levels simulation indicates new defect levels appear in the forbidden gap of LN:Bi crystals. Therefore bismuth can act as photorefractive centers in LN crystals.

  8. Ferroelectric domain inversion and its stability in lithium niobate thin film on insulator with different thicknesses

    SciTech Connect

    Shao, Guang-hao; Bai, Yu-hang; Cui, Guo-xin; Li, Chen; Qiu, Xiang-biao; Wu, Di; Lu, Yan-qing; Geng, De-qiang

    2016-07-15

    Ferroelectric domain inversion and its effect on the stability of lithium niobate thin films on insulator (LNOI) are experimentally characterized. Two sets of specimens with different thicknesses varying from submicron to microns are selected. For micron thick samples (∼28 μm), domain structures are achieved by pulsed electric field poling with electrodes patterned via photolithography. No domain structure deterioration has been observed for a month as inspected using polarizing optical microscopy and etching. As for submicron (540 nm) films, large-area domain inversion is realized by scanning a biased conductive tip in a piezoelectric force microscope. A graphic processing method is taken to evaluate the domain retention. A domain life time of 25.0 h is obtained and possible mechanisms are discussed. Our study gives a direct reference for domain structure-related applications of LNOI, including guiding wave nonlinear frequency conversion, nonlinear wavefront tailoring, electro-optic modulation, and piezoelectric devices.

  9. Photoreduction of metal nanostructures on periodically proton exchanged MgO-doped lithium niobate crystals

    SciTech Connect

    Balobaid, Laila; Craig Carville, N.; Collins, Liam; Rodriguez, Brian J.; Manzo, Michele; Gallo, Katia

    2013-10-28

    Local reactivity on periodically proton exchanged lithium niobate (PPE:LN) surfaces is a promising route for the fabrication of regularly spaced nanostructures. Here, using MgO-doped PPE:LN templates, we investigate the influence of the doping on the nanostructure formation as a function of the proton exchange (PE) depth. The deposition is found to occur preferentially along the boundary between MgO-doped LN and the PE region when the PE depth is at least 1.73 μm, however, for shallower depths, deposition occurs across the entire PE region. The results are found to be consistent with an increased photoconductivity of the MgO-doped LN.

  10. Electro-optically tunable, multi-wavelength optical parametric generators in aperiodically poled lithium niobates.

    PubMed

    Chen, Y H; Chung, H P; Chang, W K; Lyu, H T; Chang, J W; Tseng, C H

    2012-12-17

    We report on the design and demonstration of electro-optically tunable, multi-wavelength optical parametric generators (OPGs) based on aperiodically poled lithium niobate (APPLN) crystals. Two methods have been proposed to significantly enhance the electro-optic (EO) tunability of an APPLN OPG constructed by the aperiodic optical superlattice (AOS) technique. This is done by engineering the APPLN domain structure either in the crystal fabrication or in the crystal design process to increase the length or block-number difference of the two opposite-polarity domains used in the structure. Several orders of magnitude enhancement on the EO tuning rate of the APPLN OPGs constructed by the proposed techniques for simultaneous multiple signal wavelength generation over a conventional one has been demonstrated in a near infrared band (1500-1600 nm).

  11. Highly sensitive absorption measurements in lithium niobate using whispering gallery resonators

    NASA Astrophysics Data System (ADS)

    Leidinger, Markus; Buse, Karsten; Breunig, Ingo

    2015-02-01

    The absorption coefficient of undoped, congruently grown lithium niobate (LiNbO3) for ordinarily and extraordinarily polarized light is measured in the wavelength range from 390 to 2600 nm using whispering gallery resonators (WGRs). These monolithic cavities guide light by total internal reflection. Their high Q-factor provides several hundred meters of propagation for the coupled light in millimetre size resonators allowing for the measurement of absorption coefficients below 10-2 cm-1, where standard methods such as Fourier-transform or grating spectroscopy meet their limit. In this work the lowest measured value is 10-4 cm-1 at 1700 nm wavelength. Furthermore, the known OH- overtone at 1470 nm wavelength can be resolved clearly.

  12. Monolithically integrated multi-wavelength filter and second harmonic generator in aperiodically poled lithium niobate.

    PubMed

    Chang, C L; Chen, Y H; Lin, C H; Chang, J Y

    2008-10-27

    We report on the design and experimental characterization of aperiodically poled lithium niobate (APLN) crystals for use in monolithically integrated dual nonlinear-optical devices. A cascade and a single aperiodic-domain-structure designs based on simulated annealing method were constructed in LiNbO(3) to simultaneously perform as 4-channel electro-optically active (EOA) filters and 4-channel frequency doublers in the telecom band. We found that we could obtain a 2.44-fold enhancement in second-harmonic-generation conversion efficiency and a 2.4-time reduction in filter transmission bandwidth with the single APLN device over the cascade one when the same device length of 2 cm and the EOA field of 1027 V/mm were used.

  13. Design considerations for quasi-phase-matching in doubly resonant lithium niobate hexagonal micro-resonators

    NASA Astrophysics Data System (ADS)

    Sono, Tleyane J.; Riziotis, Christos; Mailis, Sakellaris; Eason, Robert W.

    2017-09-01

    Fabrication capabilities of high optical quality hexagonal superstructures by chemical etching of inverted ferroelectric domains in lithium niobate platform suggests a route for efficient implementation of compact hexagonal microcavities. Such nonlinear optical hexagonal micro-resonators are proposed as a platform for second harmonic generation (SHG) by the combined mechanisms of total internal reflection (TIR) and quasi-phase-matching (QPM). The proposed scheme for SHG via TIR-QPM in a hexagonal microcavity can improve the efficiency and also the compactness of SHG devices compared to traditional linear-type based devices. A simple theoretical model based on six-bounce trajectory and phase matching conditions was capable for obtaining the optimal cavity size. Furthermore numerical simulation results based on finite difference time domain beam propagation method analysis confirmed the solutions obtained by demonstrating resonant operation of the microcavity for the second harmonic wave produced by TIR-QPM. Design aspects, optimization issues and characteristics of the proposed nonlinear device are presented.

  14. Microlaser-pumped periodically poled lithium niobate optical parametric generator-optical parametric amplifier.

    PubMed

    Aniolek, K W; Schmitt, R L; Kulp, T J; Richman, B A; Bisson, S E; Powers, P E

    2000-04-15

    For what is believed to be the first time, a single-longitudinal-mode passively Q-switched Nd:YAG microlaser is used to pump a narrow-bandwidth periodically poled lithium niobate (PPLN) optical parametric generator-optical parametric amplifier (OPG-OPA). Before amplification in the OPA, the output of the OPG stage was spectrally filtered with an air-spaced etalon, resulting in spectroscopically useful radiation (bandwidth, ~0.05 cm(-1) FWHM) that was tunable in 15-cm(-1) segments anywhere in the signal range 6820-6220 cm(-1) and the idler range 2580-3180 cm(-1). The ability to pump an OPG-OPA with compact, high-repetition-rate, intrinsically narrow-bandwidth microlasers is made possible by the high gain of PPLN. The result is a tunable light source that is well suited for use in portable spectroscopic gas sensors.

  15. The H+ related defects in near-stoichiometric lithium niobate crystals investigated by domain reversal

    NASA Astrophysics Data System (ADS)

    Yan, Wenbo; Kong, Yongfa; Shi, Lihong; Xie, Xiang; Li, Xiaochun; Xu, Jingjun; Lou, Cibo; Liu, Hongde; Zhang, Wanlin; Zhang, Guangyin

    2004-07-01

    Domain reversal and heat treatment were carried out on near-stoichiometric lithium niobate crystals and H+ related defect structure of this crystal was studied through infrared absorption spectra. It is found that the position and halfwidth of some deconvoluted peaks of absorption band change apparently during domain reversal and heat treatment. According to these experimental results, a more suitable model about the location of Li-vacancy in LiNbO3 is introduced. In this model, the four Li vacancies, charge-compensating an anti-site Nb5+ ion (Nb4+Li), occupy two types of lattice positions: three of them at the nearest Li-sites Nb4+Li and the other one at a nearer Li-site above the same oxygen plane with Nb4+Li.

  16. Low temperature dc electrical conduction in reduced lithium niobate single crystals

    NASA Astrophysics Data System (ADS)

    Dhar, Ajay; Singh, Nidhi; Singh, Rajiv K.; Singh, Ramadhar

    2013-01-01

    The direct current (dc) electrical conductivity of unreduced and reduced lithium niobate (LiNbO3) single crystals has been measured at room temperature (˜300 K). The dc conductivity and activation energy show strong dependence on the degree of oxygen reduction in LiNbO3 single crystals. The dc conductivity exhibits a peak as a function of increasing degree of oxygen reduction. These results have been analysed assuming small polaron hopping conduction between Nb4+ and Nb5+ ion sites. The temperature dependence of dc conductivity of reduced LiNbO3 single crystal, exhibiting the highest dc conductivity, has been examined in the temperature range 77-373 K. The observed dc conductivity data has been analyzed and explained in terms of Mott’s variable range hopping (VRH) conduction model involving a single phonon hopping process.

  17. Spectral broadening in lithium niobate in a self-diffraction geometry using ultrashort pulses

    NASA Astrophysics Data System (ADS)

    Dharmadhikari, Jayashree A.; Dota, Krithika; Mathur, Deepak; Dharmadhikari, Aditya K.

    2016-05-01

    We report on broadband light generation in the impulsive regime in an un-doped lithium niobate (LiNbO3) crystal by two femtosecond laser pulses (36 fs) from a Ti-sapphire laser amplifier. We systematically investigate the role of incident intensity on spectral broadening. At relatively low incident intensity (0.7 TW cm-2), spectral broadening in the transmitted beam occurs due to the combined effect of self-phase modulation and cross-phase modulation. At higher incident intensity (10.2 TW cm-2), we observe generation of as many as 21 anti-Stokes orders due to coherent anti-Stokes Raman scattering in self-diffraction geometry. Moreover, we observe order-dependent spectral broadening of anti-Stokes lines that may be attributed to the competition with other nonlinear optical effects like cross-phase modulation.

  18. Dependence of stoichiometry of lithium niobate nanocrystals on initial lithium to niobium ratios in the synthesis step

    NASA Astrophysics Data System (ADS)

    Veenhuizen, K.; Stone, G. A.; Knabe, B.; Buse, K.; Dierolf, V.

    2017-02-01

    Ferroelectric nanocrystals show promise for application in forming hybridized nonlinear materials with liquid crystals. It is well known that bulk single crystals of lithium niobate (LiNbO3) are most easily grown in a congruent (lithium-deficient) form but can also be grown in a stoichiometric form. This is controlled by the specific growth conditions and the stoichiometric ratio ρ = MLi/(MLi + MNb), where M is the molar fraction. This work explores the dependence of the stoichiometry of LiNbO3 nanocrystals on the value of ρ in the synthesis step. Batches of LiNbO3 nanocrystals were synthesized using a sol-gel method. The nanocrystals were analysed via SEM and Raman spectroscopy to gain information about their morphology, stoichiometry, defect content, and phase. For bulk crystals, previous work has demonstrated that the spectral widths of specific Raman modes strongly depend on ρ. For the nanocrystals, the Raman spectra indeed reveal that the resultant nanocrystal stoichiometry depends on the initial ρ used in the synthesis step. In addition, a close examination of the Raman spectra reveals the presence of an extra phase in batches with ρ ≥ 55%. Somewhat counterintuitively, this phase is identified by its Raman spectra to be LiNb3O8, a relatively lithium-poor phase compared to LiNbO3. Avoiding this extra phase, we find that high quality, roughly spherical LiNbO3 nanocrystals can be synthesized for ρ between 52 and 54%.

  19. Optical composite nanostructures produced by silver ion implantation of lithium niobate

    NASA Astrophysics Data System (ADS)

    Sarkisov, Sergey S.; Curley, Michael J.; Williams, Eric K.; Ila, Dariush; Svetchnikov, Vasili L.; Zandbergen, Henny W.; Poker, David B.; Hensley, Dale K.

    2000-06-01

    We analyze microstructure and optical properties of thin light-guiding nanocompositte planar structures produced by implantation of MeV Ag into LiNbO3. The structures demonstrate such prominent features as change of color from yellow to pink accompanied by the appearance of light guiding after heat treatment of the implanted sample at 500 degree(s)C for one hour in open air. TEM analysis shows that before heat treatment the implanted region consists of amorphous and porous lithium niobate and nanoclusters of metallic silver localized near the edge of the nuclear stopping region. The surface plasmon resonance peak attributed to the nanoclusters is located near 430 nm giving yellow color to the sample. After heat treatment the implanted region re-crystallizes in the form of randomly oriented sub-micron grains of lithium niobate doped with enlarged and dispersed silver nanoclusters. Optical prism coupling analysis shows that the implanted region performs as a planar light guide with the refractive index apparently higher than the nuclear stopping region beneath it. In addition, the surface plasmon resonance peak of the nanoclusters moves to 550 nm giving pink color to the sample. Using computer simulations based on the Mie model, we explain such significant red frequency shift of the plasmon resonance by the increase of the effective refractive index of the host material after recrystallization and elimination of porosity caused by heat treatment. Theoretical data are in good agreement with experimental spectra of the optical extinction of the sample before and after heat treatment. This is also in agreement with the fact that the implanted planar structure becomes a light guide with substantially increased effective refractive index. Fabricated nanostructure can find application in ultra-fast photonic switches where light guiding is combined with the optical nonlinearity of the third order enhanced by the plasmon resonance.

  20. Lithium niobate stress gauge current diagnostic for noninductive measurement of fast-rise-time multimegampere currents

    NASA Astrophysics Data System (ADS)

    Hanson, D. L.; Williams, R. R.; Porter, J. L.; Spielman, R. B.; Matzen, M. K.

    1990-11-01

    Accurate modeling of load behavior in Z-pinch plasma radiation sources driven by high-current generators requires the measurement of fast-rise-time multimegampere currents close to the load. Conventional current diagnostics mounted in inductive cavities (such as B-dot loops and Rogowski coils) fail at small radius because of electrical breakdown produced by high dI/dt. In this paper, we describe the use of large-signal, nanosecond-time-resolution lithium niobate piezoelectric stress gauges to directly measure the magnetic pressure B2/2μ0=μ0I2/8π2r2 generated at radius r by a current I flowing in a radial transmission line. Current measurements have been performed at radius r=2.54×10-2 m on Sandia National Laboratories' Proto-II (10 TW) and SATURN (30 TW) gas puff Z-pinch experiments with maximum currents of 10.1 MA and dI/dt to 2.1×1014 A/s. Comparisons with Faraday rotation and B-dot current diagnostic measurements at large radius are presented. Bremsstrahlung noise problems unique to the SATURN gas puff source are discussed. For a Y-cut lithium niobate stress gauge on a pure tungsten electrode, current densities up to I/2πr=78 MA/m can be measured before the electrode yield strength and the piezoelectric operating stress limit are exceeded. Above the Hugoniot elastic limit of the electrode material, the dynamic range and accuracy of the diagnostic are greatly reduced, but it appears that the technique can be extended to higher current densities using an X-cut quartz piezoelectric element and a tungsten-sapphire electrode impedance stack.

  1. Integrated RF photonic devices based on crystal ion sliced lithium niobate

    NASA Astrophysics Data System (ADS)

    Stenger, Vincent; Toney, James; Pollick, Andrea; Busch, James; Scholl, Jon; Pontius, Peter; Sriram, Sri

    2013-03-01

    This paper reports on the development of thin film lithium niobate (TFLN™) electro-optic devices at SRICO. TFLN™ is formed on various substrates using a layer transfer process called crystal ion slicing. In the ion slicing process, light ions such as helium and hydrogen are implanted at a depth in a bulk seed wafer as determined by the implant energy. After wafer bonding to a suitable handle substrate, the implanted seed wafer is separated (sliced) at the implant depth using a wet etching or thermal splitting step. After annealing and polishing of the slice surface, the transferred film is bulk quality, retaining all the favorable properties of the bulk seed crystal. Ion slicing technology opens up a vast design space to produce lithium niobate electro-optic devices that were not possible using bulk substrates or physically deposited films. For broadband electro-optic modulation, TFLN™ is formed on RF friendly substrates to achieve impedance matched operation at up to 100 GHz or more. For narrowband RF filtering functions, a quasi-phase matched modulator is presented that incorporates domain engineering to implement periodic inversion of electro-optic phase. The thinness of the ferroelectric films makes it possible to in situ program the domains, and thus the filter response, using only few tens of applied volts. A planar poled prism optical beam steering device is also presented that is suitable for optically switched true time delay architectures. Commercial applications of the TFLN™ device technologies include high bandwidth fiber optic links, cellular antenna remoting, photonic microwave signal processing, optical switching and phased arrayed radar.

  2. Pyroelectric field assisted ion migration induced by ultraviolet laser irradiation and its impact on ferroelectric domain inversion in lithium niobate crystals

    SciTech Connect

    Ying, C. Y. J.; Mailis, S.; Daniell, G. J.; Steigerwald, H.; Soergel, E.

    2013-08-28

    The impact of UV laser irradiation on the distribution of lithium ions in ferroelectric lithium niobate single crystals has been numerically modelled. Strongly absorbed UV radiation at wavelengths of 244–305 nm produces steep temperature gradients which cause lithium ions to migrate and result in a local variation of the lithium concentration. In addition to the diffusion, here the pyroelectric effect is also taken into account which predicts a complex distribution of lithium concentration along the c-axis of the crystal: two separated lithium deficient regions on the surface and in depth. The modelling on the local lithium concentration and the subsequent variation of the coercive field are used to explain experimental results on the domain inversion of such UV treated lithium niobate crystals.

  3. Comparative study on three highly sensitive absorption measurement techniques characterizing lithium niobate over its entire transparent spectral range.

    PubMed

    Leidinger, M; Fieberg, S; Waasem, N; Kühnemann, F; Buse, K; Breunig, I

    2015-08-24

    We employ three highly sensitive spectrometers: a photoacoustic spectrometer, a photothermal common-path interferometer and a whispering-gallery-resonator-based absorption spectrometer, for a comparative study of measuring the absorption coefficient of nominally transparent undoped, congruently grown lithium niobate for ordinarily and extraordinarily polarized light in the wavelength range from 390 to 3800 nm. The absorption coefficient ranges from below 10(-4) cm(-1) up to 2 cm(-1). Furthermore, we measure the absorption at the Urbach tail as well as the multiphonon edge of the material by a standard grating spectrometer and a Fourier-transform infrared spectrometer, providing for the first time an absorption spectrum of the whole transparency window of lithium niobate. The absorption coefficients obtained by the three highly sensitive and independent methods show good agreement.

  4. Impact of the photorefractive and pyroelectric-electro-optic effect in lithium niobate on whispering-gallery modes.

    PubMed

    Leidinger, Markus; Werner, Christoph S; Yoshiki, Wataru; Buse, Karsten; Breunig, Ingo

    2016-12-01

    Whispering-gallery resonators made of undoped and MgO-doped congruently grown lithium niobate are used to study electro-optic refractive index changes. Hereby, we focus on the volume photovoltaic and the pyroelectric effect, both providing an electric field driving the electro-optic effect. Our findings indicate that the light-induced photorefractive effect, combining the photovoltaic and electro-optic effect, is present only in the non-MgO-doped lithium niobate for exposure with light having wavelengths of up to 850 nm. This leads to strong resonance frequency shifts of the whispering-gallery modes. No photorefractive effect was observed in the MgO-doped material. One has to be aware that surface charges induced by the pyroelectric effect result in a similar phenomenon and are present in both materials.

  5. Electro-optic modulation of high-Q lithium niobate whispering gallery resonator with integrated ground plane (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Douglas, Kenneth; Moore, Jeremy; Friedman, Thomas; Eichenfield, Matthew

    2017-02-01

    We experimentally demonstrate electro-optic modulation in thin film lithium niobate microdisk resonators with an integrated bottom electrode fabricated from a z-cut Lithium Niobate on Insulator wafer. The structure consisted of a 400nm thick crystalline z-cut lithium niobate/2um SiO2/20nm Cr/100nm Au/10nm Cr film stack on top of a z-cut lithium niobate handle wafer. The integrated bottom electrode is located 2um beneath the resonator. This proximity, coupled with positioning an electrical probe close to the top of the resonator, allows large optical frequency shifts with low voltages. We observed a 0.111pm/V resonance shift of vertically polarized (TM) optical whispering gallery modes, with the voltage applied perpendicular to the wafer surface. This corresponds to a shift of one optical linewidth at an applied voltage of 180V, using the r33 component of the eletro-optic tensor. We observed a smaller shift of 0.066pm/V for the radially polarized (TE) modes, using the r13 component of the electro-optic tensor. The experiment was performed using a 1550nm tunable laser that was coupled to the optical resonator modes using a tapered optical fiber. To measure the electro-optic shift of the resonance, a voltage was applied across the device via DC probe tips and the peak shift was calibrated with a Toptica WS6 IR wavemeter with 200 MHz absolute accuracy. We also present a finite element model that accurately predicts the resonance shift as a function of applied voltage for both polarizations.

  6. Domain switching by electron beam irradiation of Z{sup +}-polar surface in Mg-doped lithium niobate

    SciTech Connect

    Shur, V. Ya. Chezganov, D. S.; Smirnov, M. M.; Alikin, D. O.; Neradovskiy, M. M.; Kuznetsov, D. K.

    2014-08-04

    The appearance of the static domains with depth above 200 μm in the bulk of MgO-doped lithium niobate single crystals as a result of focused electron beam irradiation of Z{sup +}-polar surface was demonstrated. The created domain patterns were visualized by high-resolution methods including piezoresponse force microscopy, scanning electron microscopy, and confocal Raman microscopy. The main stages of the domain structure formation were revealed and explained in terms of the original model.

  7. Disordered lithium niobate rock-salt materials prepared by hydrothermal synthesis.

    PubMed

    Modeshia, Deena R; Walton, Richard I; Mitchell, Martin R; Ashbrook, Sharon E

    2010-07-14

    An investigation of the one-step hydrothermal crystallisation of lithium niobates reveals that reaction between Nb(2)O(5) and aqueous LiOH at 240 degrees C yields materials with a disordered rock-salt structure where the metals are statistically distributed over the cation sites. This contrasts with the well-studied reaction between Nb(2)O(5) and NaOH or KOH that produces ANbO(3) (A = Na, K) perovskites. Powder neutron diffraction shows that materials prepared at short reaction times and lower LiOH concentration (2.5 M) are lithium deficient and have a slight excess of niobium, but that at longer periods of reaction in 5 M LiOH, close to the ideal, stoichiometric Li(0.75)Nb(0.25)O composition is produced. Upon annealing this phase cleanly transforms into the known ordered rock-salt material Li(3)NbO(4), a process we have followed using thermodiffractometry, which indicates that transformation begins at approximately 700 degrees C. Solid-state (93)Nb and (7)Li NMR of the disordered and ordered rock-salt phases shows that both contain single metal sites but there is clear evidence for local disorder in the disordered samples. For the ordered material, NMR parameters derived from experiment are also compared to those calculated using density functional theory and are shown to be in good agreement.

  8. Lithium Niobate active beam combiners: results of on-chip fringe locking, fringe scanning and high contrast integrated optics interferometry and spectrometry

    NASA Astrophysics Data System (ADS)

    Martin, Guillermo; Heidmann, Samuel; Thomas, Fabrice; de Mengin, Mikhael; Jocou, Laurent; Ulliac, Gwenn; Courjal, Nadège; Morand, Alain; Benech, Pierre; le Coarer, Etienne P.

    2014-07-01

    The context of this work is the development of integrated optic beam combiners devoted to high contrast interferometry, in particular for exoplanet spectral characterization and future spatial missions, where the use of compact and light optical beam combiners ensures robustness and stability of the interferometric signal. Thus, the development of materials allowing light confinement in both polarizations, together with a good transparency from the visible to the mid-IR and able to achieve electro-optic modulation, in order to finely tune the relative phase of the interacting fields, is knowing a rapid development. Lithium Niobate is an electro-optical material allowing index, and thus optical phase modification, by application of an external electric field. It is also well known for waveguide realization in the visible, near and midinfrared. Here we present results on near and mid-infrared beam combiners achieving different optical functions: a) three telescope AC beam combiner, devoted to phase closure studies; b) Phase locking and fringe scanning using double Mach-Zehnder concept. Optimization of the fringe contrast by real time on-chip phase and photometry balance and c) High Resolution Spectrometers in channel waveguides.

  9. Multiple-wavelength second-harmonic generations in a two-dimensional periodically poled lithium niobate

    NASA Astrophysics Data System (ADS)

    Ni, Peigen; Ma, Boqin; Feng, Shuai; Cheng, Bingying; Zhang, Daozhong

    2004-03-01

    A two-dimensional nonlinear photonic crystal of lithium niobate with rectangular lattice was fabricated. In this crystal, the quasiphase-matching conditions can be satisfied in different directions for different wavelengths. As a tunable optical parametric oscillator pumped by an yttritium-aluminum-garnet laser with about 4 ns pulse duration was used, we obtained the second-harmonic output at 676 nm (red) and 571 nm (yellow) by the first-order quasiphase-matching, and at 532 nm (green) and 460 nm (blue) by the second-order quasiphase-matching, respectively. The conversion efficiency of fundamental wavelength 1352 and 1142 nm was 33% and 48.2% when the average input power was 1.47 and 2.8 mW, respectively. Our results imply that by using only one frequency conversion element, coherent beams with various colors may be attained. The application of such a two-dimensional nonlinear photonic crystal in the field of color display is expected.

  10. Domain patterning by electron beam of MgO doped lithium niobate covered by resist

    SciTech Connect

    Shur, V. Ya. Chezganov, D. S.; Akhmatkhanov, A. R.; Kuznetsov, D. K.

    2015-06-08

    Periodical domain structuring by focused electron beam irradiation of MgO-doped lithium niobate (MgOCLN) single crystalline plate covered by resist layer was studied both experimentally and by computer simulation. The dependences of domain size on the charge dose and distance between isolated domains were measured. It has been shown that the quality of periodical domain pattern depends on the thickness of resist layer and electron energy. The experimentally obtained periodic domain structures have been divided into four types. The irradiation parameters for the most uniform patterning were obtained experimentally. It was shown by computer simulation that the space charge slightly touching the crystal surface produced the maximum value of electric field at the resist/LN interface thus resulting in the best pattern quality. The obtained knowledge allowed us to optimize the poling process and to make the periodical domain patterns in 1-mm-thick wafers with an area up to 1 × 5 mm{sup 2} and a period of 6.89 μm for green light second harmonic generation. Spatial distribution of the efficiency of light frequency conversion confirmed the high homogeneity of the tailored domain patterns.

  11. Domain patterning by electron beam of MgO doped lithium niobate covered by resist

    NASA Astrophysics Data System (ADS)

    Shur, V. Ya.; Chezganov, D. S.; Akhmatkhanov, A. R.; Kuznetsov, D. K.

    2015-06-01

    Periodical domain structuring by focused electron beam irradiation of MgO-doped lithium niobate (MgOCLN) single crystalline plate covered by resist layer was studied both experimentally and by computer simulation. The dependences of domain size on the charge dose and distance between isolated domains were measured. It has been shown that the quality of periodical domain pattern depends on the thickness of resist layer and electron energy. The experimentally obtained periodic domain structures have been divided into four types. The irradiation parameters for the most uniform patterning were obtained experimentally. It was shown by computer simulation that the space charge slightly touching the crystal surface produced the maximum value of electric field at the resist/LN interface thus resulting in the best pattern quality. The obtained knowledge allowed us to optimize the poling process and to make the periodical domain patterns in 1-mm-thick wafers with an area up to 1 × 5 mm2 and a period of 6.89 μm for green light second harmonic generation. Spatial distribution of the efficiency of light frequency conversion confirmed the high homogeneity of the tailored domain patterns.

  12. Influence of annealing on the photodeposition of silver on periodically poled lithium niobate

    DOE PAGES

    Carville, N. Craig; Neumayer, Sabine M.; Manzo, Michele; ...

    2016-02-03

    Here, the preferential deposition of metal nanoparticles onto periodically poled lithium niobate surfaces, whereby photogenerated electrons accumulate in accordance with local electric fields and reduce metal ions from solution, is known to depend on the intensity and wavelength of the illumination and the concentration of the solution used. Here, it is shown that for identical deposition conditions (wavelength, intensity, concentration), post-poling annealing for 10 h at 200 °C modifies the surface reactivity through the reorientation of internal defect fields. Whereas silver nanoparticles deposit preferentially on the +z domains on unannealed crystals, the deposition occurs preferentially along 180 degrees domain wallsmore » for annealed crystals. In neither case is the deposition selective; limited deposition occurs also on the unannealed -z domain surface and on both annealed domain surfaces. The observed behavior is attributed to a relaxation of the poling-induced defect frustration mediated by Li+ ion mobility during annealing, which affects the accumulation of electrons, thereby changing the surface reactivity. The evolution of the defect field with temperature is corroborated using Raman spectroscopy.« less

  13. Influence of annealing on the photodeposition of silver on periodically poled lithium niobate

    SciTech Connect

    Carville, N. Craig; Neumayer, Sabine M.; Rodriguez, Brian J.; Manzo, Michele; Baghban, Mohammad-Amin; Gallo, Katia; Ivanov, Ilia N.

    2016-02-07

    The preferential deposition of metal nanoparticles onto periodically poled lithium niobate surfaces, whereby photogenerated electrons accumulate in accordance with local electric fields and reduce metal ions from solution, is known to depend on the intensity and wavelength of the illumination and the concentration of the solution used. Here, it is shown that for identical deposition conditions (wavelength, intensity, concentration), post-poling annealing for 10 h at 200 °C modifies the surface reactivity through the reorientation of internal defect fields. Whereas silver nanoparticles deposit preferentially on the +z domains on unannealed crystals, the deposition occurs preferentially along 180° domain walls for annealed crystals. In neither case is the deposition selective; limited deposition occurs also on the unannealed –z domain surface and on both annealed domain surfaces. The observed behavior is attributed to a relaxation of the poling-induced defect frustration mediated by Li{sup +} ion mobility during annealing, which affects the accumulation of electrons, thereby changing the surface reactivity. The evolution of the defect field with temperature is corroborated using Raman spectroscopy.

  14. Influence of annealing on the photodeposition of silver on periodically poled lithium niobate

    SciTech Connect

    Carville, N. Craig; Neumayer, Sabine M.; Manzo, Michele; Baghban, Mohammad-Amin; Ivanov, Ilia N.; Gallo, Katia; Rodriguez, Brian J.

    2016-02-03

    Here, the preferential deposition of metal nanoparticles onto periodically poled lithium niobate surfaces, whereby photogenerated electrons accumulate in accordance with local electric fields and reduce metal ions from solution, is known to depend on the intensity and wavelength of the illumination and the concentration of the solution used. Here, it is shown that for identical deposition conditions (wavelength, intensity, concentration), post-poling annealing for 10 h at 200 °C modifies the surface reactivity through the reorientation of internal defect fields. Whereas silver nanoparticles deposit preferentially on the +z domains on unannealed crystals, the deposition occurs preferentially along 180 degrees domain walls for annealed crystals. In neither case is the deposition selective; limited deposition occurs also on the unannealed -z domain surface and on both annealed domain surfaces. The observed behavior is attributed to a relaxation of the poling-induced defect frustration mediated by Li+ ion mobility during annealing, which affects the accumulation of electrons, thereby changing the surface reactivity. The evolution of the defect field with temperature is corroborated using Raman spectroscopy.

  15. Investigation of pyroelectric electron emission from monodomain lithium niobate single crystals

    NASA Astrophysics Data System (ADS)

    Bourim, El Mostafa; Moon, Chang-Wook; Lee, Seung-Woon; Kyeong Yoo, In

    2006-09-01

    The behaviors of thermally stimulated electron emission from pyroelectric monodomain lithium niobate single crystal (LiNbO 3) were investigated by utilizing a Si p-n junction photodiode as electron detector and a receptive electron beam resist (E-beam resist) as electron collector. In high vacuum (10 -6 Torr), the pyroelectric electron emission (PEE) was found to depend on the exposed emitting polar crystal surface (+ Z face or - Z face) and was significantly influenced by the emitter-electron receiver gap distances. Thus, the PEE from + Z face was detected during heating and was activated, in small gaps (<2 mm), by field emission effect on which was superposed an intense field ionization effect that primed intermittent runway ionizations (plasma breakdown into a glow discharge). In large gaps (>2 mm) the emission was simply mastered by field emission effect. Whereas, The PEE from - Z face was detected during cooling and was solely due to the field ionization effect. Therewith, for small gaps (<2 mm) the emission was governed by intermittent runway ionization ignitions resulting from a high ionization degree leading to dense plasma formation, and for large gaps (>2 mm) PEE was governed by field ionization generating a soft and continuous plasma ambient atmosphere. Significant decrease of electron emission current was observed from + Z face after successive thermal cycles. A fast and fully emission recovery was established after a brief exposure of crystal to a poor air vacuum of 10 -1 Torr.

  16. Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

    DOE PAGES

    Neumayer, Sabine M.; Strelcov, Evgheni; Manzo, Michele; ...

    2015-12-28

    Mg doped lithium niobate (Mg:LN) exhibits several advantages over undoped LN such as resistance to photorefraction, lower coercive fields, and p-type conductivity that is particularly pronounced at domain walls and opens up a range of applications, e.g., in domain wall electronics. Engineering of precise domain patterns necessitates well founded knowledge of switching kinetics, which can differ significantly from that of undoped LN. In this work, the role of humidity and sample composition in polarization reversal has been investigated under application of the same voltage waveform. Control over domain sizes has been achieved by varying the sample thickness and initial polarizationmore » as well as atmospheric conditions. Additionally, local introduction of proton exchanged phases allows for inhibition of domain nucleation or destabilization, which can be utilized to modify domain patterns. In polarization dependent current flow, attributed to charged domain walls and band bending, it the rectifying ability of Mg: LN in combination with suitable metal electrodes that allow for further tailoring of conductivity is demonstrated.« less

  17. Low energy electron imaging of domains and domain walls in magnesium-doped lithium niobate

    PubMed Central

    Nataf, G. F.; Grysan, P.; Guennou, M.; Kreisel, J.; Martinotti, D.; Rountree, C. L.; Mathieu, C.; Barrett, N.

    2016-01-01

    The understanding of domain structures, specifically domain walls, currently attracts a significant attention in the field of (multi)-ferroic materials. In this article, we analyze contrast formation in full field electron microscopy applied to domains and domain walls in the uniaxial ferroelectric lithium niobate, which presents a large 3.8 eV band gap and for which conductive domain walls have been reported. We show that the transition from Mirror Electron Microscopy (MEM – electrons reflected) to Low Energy Electron Microscopy (LEEM – electrons backscattered) gives rise to a robust contrast between domains with upwards (Pup) and downwards (Pdown) polarization, and provides a measure of the difference in surface potential between the domains. We demonstrate that out-of-focus conditions of imaging produce contrast inversion, due to image distortion induced by charged surfaces, and also carry information on the polarization direction in the domains. Finally, we show that the intensity profile at domain walls provides experimental evidence for a local stray, lateral electric field. PMID:27608605

  18. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

    NASA Astrophysics Data System (ADS)

    Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2017-04-01

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

  19. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

    PubMed Central

    Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2017-01-01

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices. PMID:28406177

  20. Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

    SciTech Connect

    Neumayer, Sabine M.; Strelcov, Evgheni; Manzo, Michele; Gallo, Katia; Kravchenko, Ivan I.; Kholkin, Andrei L.; Kalinin, Sergei V.; Rodriguez, Brian J.

    2015-12-28

    Mg doped lithium niobate (Mg:LN) exhibits several advantages over undoped LN such as resistance to photorefraction, lower coercive fields, and p-type conductivity that is particularly pronounced at domain walls and opens up a range of applications, e.g., in domain wall electronics. Engineering of precise domain patterns necessitates well founded knowledge of switching kinetics, which can differ significantly from that of undoped LN. In this work, the role of humidity and sample composition in polarization reversal has been investigated under application of the same voltage waveform. Control over domain sizes has been achieved by varying the sample thickness and initial polarization as well as atmospheric conditions. Additionally, local introduction of proton exchanged phases allows for inhibition of domain nucleation or destabilization, which can be utilized to modify domain patterns. In polarization dependent current flow, attributed to charged domain walls and band bending, it the rectifying ability of Mg: LN in combination with suitable metal electrodes that allow for further tailoring of conductivity is demonstrated.

  1. Nonlinear mode switching in lithium niobate nanowaveguides to control light directionality.

    PubMed

    Escalé, Marc Reig; Sergeyev, Anton; Geiss, Reinhard; Grange, Rachel

    2017-02-20

    The ability of nanowaveguides to confine and guide light has been applied for developing optical applications such as nanolasers, optical switching and localized imaging. These and others applications can be further complemented by the optical control of the guided modes within the nanowaveguide, which in turn dictates the light emission pattern. It has been shown that the light directionality can be shaped by varying the nanowire cross-sections. Here, we demonstrate that the directionality of the light can be modified using a single nanowaveguide with a nonlinear phenomenon such as second-harmonic generation. In individual lithium niobate nanowaveguides, we use second-harmonic modal phase-matching and we apply it to switch the guided modes within its sub-micron cross-section. In doing so, we can vary the light directionality of the generated light from straight (0° with respect to the propagation direction) to large spread angles (almost 54°). Further, we characterize the directionality of the guided light by means of optical Fourier transformation and show that the directionality of the guided light changes for different wavelengths.

  2. Low energy electron imaging of domains and domain walls in magnesium-doped lithium niobate

    NASA Astrophysics Data System (ADS)

    Nataf, G. F.; Grysan, P.; Guennou, M.; Kreisel, J.; Martinotti, D.; Rountree, C. L.; Mathieu, C.; Barrett, N.

    2016-09-01

    The understanding of domain structures, specifically domain walls, currently attracts a significant attention in the field of (multi)-ferroic materials. In this article, we analyze contrast formation in full field electron microscopy applied to domains and domain walls in the uniaxial ferroelectric lithium niobate, which presents a large 3.8 eV band gap and for which conductive domain walls have been reported. We show that the transition from Mirror Electron Microscopy (MEM - electrons reflected) to Low Energy Electron Microscopy (LEEM - electrons backscattered) gives rise to a robust contrast between domains with upwards (Pup) and downwards (Pdown) polarization, and provides a measure of the difference in surface potential between the domains. We demonstrate that out-of-focus conditions of imaging produce contrast inversion, due to image distortion induced by charged surfaces, and also carry information on the polarization direction in the domains. Finally, we show that the intensity profile at domain walls provides experimental evidence for a local stray, lateral electric field.

  3. Optically induced reversible wettability transition on single crystal lithium niobate surfaces

    NASA Astrophysics Data System (ADS)

    Yan, Weishan; Zhao, Dongfang; Zhang, Ling; Jia, Ran; Gao, Naikun; Zhang, Dongdong; Luo, Wenyao; Li, Yanlu; Liu, Duo

    2017-08-01

    Solid surfaces with controllable and reversible wettability are scientifically and technologically important. Here, we report on the reversible wettability transitions of single crystal (0001) lithium niobate (LiNbO3) surfaces by alternate ultraviolet (UV) and infrared (IR) light irradiation. The UV irradiation (170 mW/cm2) could markedly reduce the contact angle of LiNbO3 over 30 min from 55.3° to 10.7°. IR irradiation (200 mW/cm2) recovered the water contact angle from 10.7° to 55.1° over 1 h. First-principles calculations showed that under both O-poor and O-rich conditions, oxygen vacancies preferred to form at the Li-terminal (0001) surface rather than at the Nb-terminal surface and the O-terminal surface or in the bulk. We further show that this light induced wettability transition has a dependence on the light wavelength. The influences of relative humidity and oxygen concentration were also investigated.

  4. Raman spectra of lithium niobate crystals heavily doped with zinc and magnesium

    NASA Astrophysics Data System (ADS)

    Sidorov, N. V.; Palatnikov, M. N.

    2016-12-01

    We have examined the Raman spectra of heavily doped lithium niobate single crystals (at close-to-threshold concentrations of doping cations): LiNbO3:Zn (4.5 mol % ZnO), LiNbO3:Mg (5.01 mol %):Fe (0.005 mol %), LiNbO3:Mg (5.1 mol %), and LiNbO3:Mg (5.3 mol % MgO). Low-intensity lines with frequencies at 209, 230, 298, 694, and 880 cm-1 have been revealed for the first time. Analysis of the data from the literature on lattice dynamics calculations from first principles (ab initio) does not make it possible to unambiguously state that these lines correspond to fundamental vibrations of the A2 symmetry species, which are forbidden for the C3 V 6 ( R3c) space group. At the same time, ab initio calculations unambiguously indicate that the experimentally observed low-intensity "superfluous" lines with the frequencies at 104 and 119 cm-1 cannot correspond to vibrations of the A2 symmetry species. It is most likely that they correspond to two-particle states of acoustic phonons with a total wave vector equal to zero.

  5. Design of a lithium niobate-on-insulator-based optical microring resonator for biosensing applications

    NASA Astrophysics Data System (ADS)

    Naznin, Shakila; Sher, Md. Sohel Mahmud

    2016-08-01

    A label-free optical microring resonator biosensor based on lithium niobate-on-insulator (LNOI) technology is designed and simulated for biosensing applications. Although silicon-on-insulator technology is quite mature over LNOI for fabricating more compact microring resonators, the latter is attractive for its excellent electro-optic, ferroelectric, piezoelectric, photoelastic, and nonlinear optic properties, which can offer a wide range of tuning facilities for sensing. To satisfy the requirement of high sensitivity in biosensing, the dual-microring resonator model is applied to design the proposed sensor. The transmission spectrum obtained from two-dimensional simulations based on finite-difference time-domain method demonstrates that the designed LNOI microring sensor consisting of a 10-μm outer ring and a 5-μm inner ring offers a sensitivity of ˜68 nm/refractive index unit (RIU) and a minimum detection limit of 10-2 RIU. Finally, the sensor's performance is simulated for glucose sensing, a biosensing application.

  6. Thickness, humidity, and polarization dependent ferroelectric switching and conductivity in Mg doped lithium niobate

    SciTech Connect

    Neumayer, Sabine M.; Rodriguez, Brian J.; Strelcov, Evgheni; Kravchenko, Ivan I.; Kalinin, Sergei V.; Manzo, Michele; Gallo, Katia; Kholkin, Andrei L.

    2015-12-28

    Mg doped lithium niobate (Mg:LN) exhibits several advantages over undoped LN such as resistance to photorefraction, lower coercive fields, and p-type conductivity that is particularly pronounced at domain walls and opens up a range of applications, e.g., in domain wall electronics. Engineering of precise domain patterns necessitates well founded knowledge of switching kinetics, which can differ significantly from that of undoped LN. In this work, the role of humidity and sample composition in polarization reversal has been investigated under application of the same voltage waveform. Control over domain sizes has been achieved by varying the sample thickness and initial polarization as well as atmospheric conditions. In addition, local introduction of proton exchanged phases allows for inhibition of domain nucleation or destabilization, which can be utilized to modify domain patterns. Polarization dependent current flow, attributed to charged domain walls and band bending, demonstrates the rectifying ability of Mg:LN in combination with suitable metal electrodes that allow for further tailoring of conductivity.

  7. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate.

    PubMed

    Witmer, Jeremy D; Valery, Joseph A; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J; Hill, Jeff T; Safavi-Naeini, Amir H

    2017-04-13

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

  8. Probing the pseudo-1-D ion diffusion in lithium titanium niobate anode for Li-ion battery.

    PubMed

    Das, Suman; Dutta, Dipak; Araujo, Rafael B; Chakraborty, Sudip; Ahuja, Rajeev; Bhattacharyya, Aninda J

    2016-08-10

    Comprehensive understanding of the charge transport mechanism in the intrinsic structure of an electrode material is essential in accounting for its electrochemical performance. We present here systematic experimental and theoretical investigations of Li(+)-ion diffusion in a novel layered material, viz. lithium titanium niobate. Lithium titanium niobate (exact composition Li0.55K0.45TiNbO5·1.06H2O) is obtained from sol-gel synthesized potassium titanium niobate (KTiNbO5) by an ion-exchange method. The Li(+)-ions are inserted and de-inserted preferentially into the galleries between the octahedral layers formed by edge and corner sharing TiO6 and NbO6 octahedral units and the effective chemical diffusion coefficient, is estimated to be 3.8 × 10(-11) cm(2) s(-1) using the galvanostatic intermittent titration technique (GITT). Calculations based on density functional theory (DFT) strongly confirm the anisotropic Li(+)-ion diffusion in the interlayer galleries and that Li(+)-ions predominantly diffuse along the crystallographic b-direction. The preferential Li(+)-ion diffusion along the b-direction is assisted by line-defects, which are observed to be higher in concentration along the b-direction compared to the a- and c-directions, as revealed by high resolution electron microscopy. The Li-Ti niobate can be cycled to low voltages (≈0.2 V) and show stable and satisfactory battery performance over 100 cycles. Due to the possibility of cycling to low voltages, cyclic voltammetry and X-ray photoelectron spectroscopy convincingly reveal the reversibility of Ti(3+) ↔ Ti(2+) along with Ti(4+) ↔ Ti(3+) and Nb(5+) ↔ Nb(4+).

  9. Conversion of broadband IR radiation and structural disorder in lithium niobate single crystals with low photorefractive effect

    NASA Astrophysics Data System (ADS)

    Litvinova, Man Nen; Syuy, Alexander V.; Krishtop, Victor V.; Pogodina, Veronika A.; Ponomarchuk, Yulia V.; Sidorov, Nikolay V.; Gabain, Aleksei A.; Palatnikov, Mikhail N.; Litvinov, Vladimir A.

    2016-11-01

    The conversion of broadband IR radiation when the noncritical phase matching condition is fulfilled in lithium niobate (LiNbO3) single crystals with stoichiometric (R = Li/Nb = 1) and congruent (R = 0.946) compositions, as well as in congruent single crystals doped with zinc has been investigated. It is shown that the spectrum parameters of converted radiation, such as the conversion efficiency, spectral width and position of maximum, depend on the ordering degree of structural units of the cation sublattice along the polar axis of crystal.

  10. Direct-laser metal writing of surface acoustic wave transducers for integrated-optic spatial light modulators in lithium niobate

    NASA Astrophysics Data System (ADS)

    Datta, Bianca C.; Savidis, Nickolaos; Moebius, Michael; Jolly, Sundeep; Mazur, Eric; Bove, V. Michael

    2017-02-01

    Recently, the fabrication of high-resolution silver nanostructures using a femtosecond laser-based direct write process in a gelatin matrix was reported. The application of direct metal writing towards feature development has also been explored with direct metal fusion, in which metal is fused onto the surface of the substrate via a femtosecond laser process. In this paper, we present a comparative study of gelatin matrix and metal fusion approaches for directly laser-written fabrication of surface acoustic wave transducers on a lithium niobate substrate for application in integrated optic spatial light modulators.

  11. Design of optical reversible logic gates using electro-optic effect of lithium niobate based Mach-Zehnder interferometers.

    PubMed

    Kumar, Santosh; Chanderkanta; Raghuwanshi, Sanjeev Kumar

    2016-07-20

    In recent years reversible logic has come as a promising solution in the optical computing domain. In reversible gates, there is one-to-one mapping between input and output, causing no loss of information. Reversible gates are useful for application in low power complementary metal-oxide semiconductors, with less dissipation, and in quantum computing. These benefits can be utilized by implementing reversible gate structures in the optical domain. In this paper, basic reversible Feynman and Fredkin logic gates using a lithium niobate based Mach-Zehnder interferometer are proposed. The different applications utilizing the proposed structures are also explained in this study.

  12. Design of reversible sequential circuits using electro-optic effect of lithium-niobate-based Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Chauhan, Chanderkanta; Bedi, Amna

    2016-12-01

    In recent years, it has been shown that reversible logic can play an important role in power optimization for computer design. The various reversible logic gates such as Feynman, Fredkin, Peres, and Toffoli gates have been discussed by researchers, but very little work has been done on reversible sequential circuits. Design of reversible sequential circuits using lithium-niobate-based Mach-Zehnder interferometers is proposed. Here, flip-flops are designed with the help of basic reversible logic gates such as Feynman, Fredkin, and Peres gates. Theoretical descriptions along with mathematical formulation of the devices are provided. The devices are also analyzed through finite difference-beam propagation method and MATLAB® simulation.

  13. Observed Polarization Dependence Of The Surface Acoustic Wave(Saw) Acousto-Optic (A-0) Interaction In Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Shockley, D. K.; Garvin, C.

    1987-11-01

    A polarization sensitivity was observed in the bandwidth and interaction efficiency during the investigation of the SAW acousto-optic (AO) interaction in lithium niobate. It was observed that input light linearly polarized along the propagation direction of the acoustic beam allowed an increased interaction bandwidth when compared with input illumination polarized orthogonal to the acoustic propagation direction. The polarization of the optical beam remained unchanged to within one part in 10,000. Experimental findings show that this polarization sensitivity was parameterized by acoustic wavelength. Results of the wavelength parameterization are reported and comparisons drawn to theoretical work performed in the Johns Hopkins University study funded by Harry Diamond Laboratories.

  14. Design of 4 to 2 line encoder using lithium niobate based Mach Zehnder Interferometers for high speed communication

    NASA Astrophysics Data System (ADS)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep; Raghuwanshi, Sanjeev K.

    2016-04-01

    Encoder is a device that allows placing digital information from many inputs to many outputs. Any application of combinational logic circuit can be implemented by using encoder and external gates. In this paper, 4 to 2 line encoder is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).

  15. Two-dimensional mapping of electro-optic phase retardation in lithium niobate crystals by digital holography.

    PubMed

    de Angelis, M; De Nicola, S; Finizio, A; Pierattini, G; Ferraro, P; Grilli, S; Paturzo, M; Sansone, L; Alfieri, D; De Natale, P

    2005-07-01

    We demonstrate accurate two-dimensional mapping of the phase retardation induced by the electro-optic effect in lithium niobate crystals. Off-axis digital holography is used to investigate congruent z-cut crystals. The spatially resolved optical path difference is interferometrically measured while a linearly rising voltage ramp is applied to the crystal. This procedure provides information on the uniformity of crystals' electro-optic properties and offers the ability to detect the presence of defects that is of fundamental importance for reliable processing of photonic devices.

  16. IR tunable narrow-band nanosecond converter with a microchip pump source and periodically-poled Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Kir'yanov, A. V.; Klimentov, S. M.; Powers, P. E.; Mel'nikov, I. V.; Korkishko, Y. N.

    2008-04-01

    We report a compact nanosecond source based on optical parametric generation in a periodically-poled Lithium Niobate slab pumped with a Nd3+:YAG/Cr4+:YAG microchip laser at the wavelength 1.064 μm and capable of generating a diffraction-limited beam widely tunable through the mid-IR. The device efficiency is shown to reach 30% at relatively low (units of μJs) pump pulse energy and its spectrum to be narrowed down to 0.2 nm using low-power CW seed provided by a DFB laser.

  17. Design of reversible multiplexer using electro-optic effect inside lithium niobate-based Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Chauhan, Chanderkanta

    2016-11-01

    With the demand of ultrahigh-speed logic, there has been an emphasis on low-power design techniques. Reversible computing has been proposed as a possible alternative to address the energy dissipation problem. Thus, the reversible circuit implementation in optical domain gives a new dimension in ultrahigh-speed, low-power consumption of quantum computing. In this study, a design of reversible multiplexer using electro-optic effect of lithium niobate-based Mach-Zehnder interferometer is proposed. It is verified using a beam propagation method along with MATLAB simulation.

  18. Strong forward-backward asymmetry of stimulated Raman scattering in lithium-niobate-based whispering gallery resonators.

    PubMed

    Leidinger, M; Sturman, B; Buse, K; Breunig, I

    2016-06-15

    We show experimentally and prove theoretically that the pump-power thresholds of stimulated Raman scattering (SRS) in lithium-niobate-based whispering gallery resonators (WGRs) are strongly different for the signal waves propagating in the backward and forward directions with respect to the pump wave. This feature is due to a strong polaritonic effect. It leads to a cascade of alternating forward-backward Raman lines with increasing pump power. The measured polarization and spectral properties of SRS are in good agreement with theory. Similar properties have to be inherent in other WGRs made of polar crystals.

  19. Optically induced three-dimensional Penrose-type photonic quasicrystal lattices in iron-doped lithium niobate crystal

    NASA Astrophysics Data System (ADS)

    Jin, Wentao; Xue, Yan Ling

    2014-07-01

    Three-dimensional Penrose-type photonic quasicrystal lattices are optically induced inside an iron-doped lithium niobate photorefractive crystal for the first time using a single multi-pinhole plate. The setup of this method is simple and compact dispense with complex optical adjustment system. Induced Penrose-type photonic quasicrystal lattices are analyzed and verified by plane wave guiding and far field diffraction pattern imaging. The quasicrystal microstructures can be maintained for a long time inside the crystal in a dark room. Other more complex three-dimensional photonic quasicrystal structures can be fabricated with this method by designing the multi-pinhole plate flexibly.

  20. Formation of Photonic Structures in Photorefractive Lithium Niobate by 1D and 2D Bessel-like Optical Fields

    NASA Astrophysics Data System (ADS)

    Inyushov, A.; Safronova, P.; Trushnikov, I.; Sarkyt, A.; Shandarov, V.

    2017-06-01

    Both, one-dimensional (1D) and two-dimensional (2D) Bessel-like beams with different topology of 2D beam cross-sections are formed from Gaussian laser beams using the amplitude masks and Fresnel biprisms. These almost diffraction-free light fields with wavelengths of 532 and 633 nm can change the refractive indices of photorefractive lithium niobate samples and form within them the nonlinear photonic diffraction structures. The characteristics of photonic structures induced in this way are studied by diffraction of monochromatic light with wavelengths of 633 and 532 nm.

  1. Interface and thickness dependent domain switching and stability in Mg doped lithium niobate

    DOE PAGES

    Neumayer, Sabine M.; Ivanov, Ilia N.; Manzo, Michele; ...

    2015-12-08

    Controlling ferroelectric switching in Mg doped lithium niobate (Mg: LN) is of fundamental importance for optical device and domain wall electronics applications that require precise domain patterns. Stable ferroelectric switching has been previously observed in undoped LN layers above proton exchanged (PE) phases that exhibit reduced polarization, whereas PE layers have been found to inhibit lateral domain growth. Here, Mg doping, which is known to significantly alter ferroelectric switching properties including coercive field and switching currents, is shown to inhibit domain nucleation and stability in Mg: LN above buried PE phases that allow for precise ferroelectric patterning via domain growthmore » control. Furthermore, piezoresponse force microscopy (PFM) and switching spectroscopy PFM reveal that the voltage at which polarization switches from the "up" to the "down" state increases with increasing thickness in pure Mg: LN, whereas the voltage required for stable back switching to the original "up" state does not exhibit this thickness dependence. This behavior is consistent with the presence of an internal frozen defect field. The inhibition of domain nucleation above PE interfaces, observed in this study, is a phenomenon that occurs in Mg: LN but not in undoped samples and is mainly ascribed to a remaining frozen polarization in the PE phase that opposes polarization reversal. This reduced frozen depolarization field in the PE phase also influences the depolarization field of the Mg: LN layer above due to the presence of uncompensated polarization charge at the PE-Mg: LN boundary. Furthermore, these alterations in internal electric fields within the sample cause long-range lattice distortions in Mg: LN via electromechanical coupling, which were corroborated with complimentary Raman measurements.« less

  2. Interface modulated currents in periodically proton exchanged Mg doped lithium niobate

    SciTech Connect

    Neumayer, Sabine M.; Rodriguez, Brian J. E-mail: gallo@kth.se; Manzo, Michele; Gallo, Katia E-mail: gallo@kth.se; Kholkin, Andrei L.

    2016-03-21

    Conductivity in Mg doped lithium niobate (Mg:LN) plays a key role in the reduction of photorefraction and is therefore widely exploited in optical devices. However, charge transport through Mg:LN and across interfaces such as electrodes also yields potential electronic applications in devices with switchable conductivity states. Furthermore, the introduction of proton exchanged (PE) phases in Mg:LN enhances ionic conductivity, thus providing tailorability of conduction mechanisms and functionality dependent on sample composition. To facilitate the construction and design of such multifunctional electronic devices based on periodically PE Mg:LN or similar ferroelectric semiconductors, fundamental understanding of charge transport in these materials, as well as the impact of internal and external interfaces, is essential. In order to gain insight into polarization and interface dependent conductivity due to band bending, UV illumination, and chemical reactivity, wedge shaped samples consisting of polar oriented Mg:LN and PE phases were investigated using conductive atomic force microscopy. In Mg:LN, three conductivity states (on/off/transient) were observed under UV illumination, controllable by the polarity of the sample and the externally applied electric field. Measurements of currents originating from electrochemical reactions at the metal electrode–PE phase interfaces demonstrate a memresistive and rectifying capability of the PE phase. Furthermore, internal interfaces such as domain walls and Mg:LN–PE phase boundaries were found to play a major role in the accumulation of charge carriers due to polarization gradients, which can lead to increased currents. The insight gained from these findings yield the potential for multifunctional applications such as switchable UV sensitive micro- and nanoelectronic devices and bistable memristors.

  3. Interface and thickness dependent domain switching and stability in Mg doped lithium niobate

    SciTech Connect

    Neumayer, Sabine M.; Rodriguez, Brian J. E-mail: brian.rodriguez@ucd.ie; Ivanov, Ilia N.; Manzo, Michele; Gallo, Katia E-mail: brian.rodriguez@ucd.ie; Kholkin, Andrei L.

    2015-12-14

    Controlling ferroelectric switching in Mg doped lithium niobate (Mg:LN) is of fundamental importance for optical device and domain wall electronics applications that require precise domain patterns. Stable ferroelectric switching has been previously observed in undoped LN layers above proton exchanged (PE) phases that exhibit reduced polarization, whereas PE layers have been found to inhibit lateral domain growth. Here, Mg doping, which is known to significantly alter ferroelectric switching properties including coercive field and switching currents, is shown to inhibit domain nucleation and stability in Mg:LN above buried PE phases that allow for precise ferroelectric patterning via domain growth control. Furthermore, piezoresponse force microscopy (PFM) and switching spectroscopy PFM reveal that the voltage at which polarization switches from the “up” to the “down” state increases with increasing thickness in pure Mg:LN, whereas the voltage required for stable back switching to the original “up” state does not exhibit this thickness dependence. This behavior is consistent with the presence of an internal frozen defect field. The inhibition of domain nucleation above PE interfaces, observed in this study, is a phenomenon that occurs in Mg:LN but not in undoped samples and is mainly ascribed to a remaining frozen polarization in the PE phase that opposes polarization reversal. This reduced frozen depolarization field in the PE phase also influences the depolarization field of the Mg:LN layer above due to the presence of uncompensated polarization charge at the PE-Mg:LN boundary. These alterations in internal electric fields within the sample cause long-range lattice distortions in Mg:LN via electromechanical coupling, which were corroborated with complimentary Raman measurements.

  4. Influence of Nd:Zn codoping in near-stoichiometric lithium niobate.

    PubMed

    Babu Reddy, J N; Ganesh Kamath, K; Vanishri, S; Bhat, H L; Elizabeth, Suja

    2008-06-28

    Near-stoichiometric lithium niobate (SLN) crystals doped with up to 1.6 mol % Zn and codoped with various Nd concentrations in the melt (0.2, 0.5, 0.9, and 1.5 mol %) (Nd:Zn:SLN) are grown from 58.6 mol % Li(2)O using conventional Czochralski technique. Crystals are pulled at the rate of 0.35 mmh with seed rotation at 9 rpm. Concentrations of Zn and Nd in the crystal are varied by adding appropriate amounts of ZnO and Nd(2)O(3) to the starting composition. Unit cell parameters of the grown crystals are calculated by Rietveld refinement method using FULLPROFF software. Domain structure studies are carried out by chemical etching followed by microscopic examination. Dielectric studies reveal the existence of piezoelectric resonance at high frequencies. Enhancement in dielectric constant and tan delta in Nd doped samples has been attributed to the space charge polarization. Nd doped samples exhibit reduction in the relative permittivity after oxygen annealing. Transmission spectra of Nd:Zn:SLN crystals in the UV region exhibit blueshift in the cutoff wavelength. In Mid Infrared (MIR) region crystals doped with 1.6 mol % Zn have shift in the OH absorption peak from 2873 to 2833 nm. Judd-Ofelt analysis carried out on the absorption spectra of codoped crystal yields the lifetime of 104 mus for the metastable state (4)F(32). The branching ratio for the electronic transition from (4)F(32) to (4)I(112) is high compared to that for (4)F(32) to (4)I(132), indicating a higher emission cross section for the former transition. Laser damage threshold evaluated using 532 nm, 5 ns pulsed neodymium doped yttrium aluminum garnet laser, shows an increase by two orders of magnitude for crystals doped with 1.6 mol % Zn. Photorefractive damage threshold for these crystals shows an enhancement of four orders of magnitude due to increase in the photoconductivity.

  5. Temperature-stable lithium niobate electro-optic Q-switch for improved cold performance

    NASA Astrophysics Data System (ADS)

    Jundt, Dieter H.

    2014-10-01

    Lithium niobate (LN) is commonly used as an electro optic (EO) Q-switch material in infrared targeting lasers because of its relatively low voltage requirements and low cost compared to other crystals. A common challenge is maintaining good performance at the sub-freezing temperatures often experienced during flight. Dropping to low temperature causes a pyro-electric charge buildup on the optical faces that leads to birefringence non-uniformity and depolarization resulting in poor hold-off and premature lasing. The most common solution has been to use radioactive americium to ionize the air around the crystal and bleed off the charge, but the radioactive material requires handling and disposal procedures that can be problematic. We have developed a superior solution that is now being implemented by multiple defense system suppliers. By applying a low level thermo-chemical reduction to the LN crystal optical faces we induce a small conductivity that allows pyro-charges to dissipate. As the material gets more heavily treated, the capacity to dissipate charges improves, but the corresponding optical absorption also increases, causing insertion loss. Even though typical high gain targeting laser systems can tolerate a few percent of added loss, the thermo-chemical processing needs to be carefully optimized. We describe the results of our process optimization to minimize the insertion loss while still giving effective charge dissipation. Treatment is performed at temperatures below 500°C and a conductivity layer less than 0.5mm in depth is created that is uniform across the optical aperture. Because the conductivity is thermally activated, the charge dissipation is less effective at low temperature, and characterization needs to be performed at cold temperatures. The trade-off between optical insertion loss and potential depolarization due to low temperature operation is discussed and experimental results on the temperature dependence of the dissipation time and the

  6. Visible quasi-phase-matched harmonic generation by electric-field-poled lithium niobate

    NASA Astrophysics Data System (ADS)

    Miller, Gregory D.; Batchko, Robert G.; Fejer, Martin M.; Byer, Robert L.

    1996-05-01

    Laser-based displays and illumination systems are applications which can capitalize on the brightness and efficiency of semiconductor lasers, provided that there is a means for converting their output into the visible spectrum. Semiconductor laser manufacturers can adjust their processes to achieve desired wavelengths in several near-infrared bands; an equally agile conversion technology is needed to permit display and illumination system manufacturers to choose visible wavelengths appropriate to their products. Quasi- phasematched second harmonic generation has the potential to convert high-power semiconductor laser output to the visible with 50% optical-to-optical conversion efficiency in a single-pass bulk configuration, using electric-field-poled lithium niobate. Lithographically- defined electrode structures on the positive or negative polar faces of this crystal are used to control the formation of domains under the influence of electric fields applied using those electrode structures. The quality of the resulting domain patterns not only controls the efficiency of quasi-phasematched second harmonic generation, but also controls the degree of resistance to photorefractive damage. We present a model which is used to identify the optimum electrode duty cycle and applied poling field for domain patterning and compare the predicted domain duty cycle with experimental results. We discuss factors which contribute to inhomogeneous domain pattern quality for samples poled under otherwise ideal conditions and our progress in limiting their influence. Finally, we present optical characterization of a 2.4 mm long 500 micrometers thick sample which produced an average second harmonic power of 1.3 W of 532 nm green from a 9 W average power Q-switched 1064 nm Nd:YAG laser in a loose- focus single-pass configuration.

  7. Interface and thickness dependent domain switching and stability in Mg doped lithium niobate

    SciTech Connect

    Neumayer, Sabine M.; Ivanov, Ilia N.; Manzo, Michele; Kholkin, Andrei L.; Gallo, Katia; Rodriguez, Brian J.

    2015-12-08

    Controlling ferroelectric switching in Mg doped lithium niobate (Mg: LN) is of fundamental importance for optical device and domain wall electronics applications that require precise domain patterns. Stable ferroelectric switching has been previously observed in undoped LN layers above proton exchanged (PE) phases that exhibit reduced polarization, whereas PE layers have been found to inhibit lateral domain growth. Here, Mg doping, which is known to significantly alter ferroelectric switching properties including coercive field and switching currents, is shown to inhibit domain nucleation and stability in Mg: LN above buried PE phases that allow for precise ferroelectric patterning via domain growth control. Furthermore, piezoresponse force microscopy (PFM) and switching spectroscopy PFM reveal that the voltage at which polarization switches from the "up" to the "down" state increases with increasing thickness in pure Mg: LN, whereas the voltage required for stable back switching to the original "up" state does not exhibit this thickness dependence. This behavior is consistent with the presence of an internal frozen defect field. The inhibition of domain nucleation above PE interfaces, observed in this study, is a phenomenon that occurs in Mg: LN but not in undoped samples and is mainly ascribed to a remaining frozen polarization in the PE phase that opposes polarization reversal. This reduced frozen depolarization field in the PE phase also influences the depolarization field of the Mg: LN layer above due to the presence of uncompensated polarization charge at the PE-Mg: LN boundary. Furthermore, these alterations in internal electric fields within the sample cause long-range lattice distortions in Mg: LN via electromechanical coupling, which were corroborated with complimentary Raman measurements.

  8. Interface modulated currents in periodically proton exchanged Mg doped lithium niobate

    NASA Astrophysics Data System (ADS)

    Neumayer, Sabine M.; Manzo, Michele; Kholkin, Andrei L.; Gallo, Katia; Rodriguez, Brian J.

    2016-03-01

    Conductivity in Mg doped lithium niobate (Mg:LN) plays a key role in the reduction of photorefraction and is therefore widely exploited in optical devices. However, charge transport through Mg:LN and across interfaces such as electrodes also yields potential electronic applications in devices with switchable conductivity states. Furthermore, the introduction of proton exchanged (PE) phases in Mg:LN enhances ionic conductivity, thus providing tailorability of conduction mechanisms and functionality dependent on sample composition. To facilitate the construction and design of such multifunctional electronic devices based on periodically PE Mg:LN or similar ferroelectric semiconductors, fundamental understanding of charge transport in these materials, as well as the impact of internal and external interfaces, is essential. In order to gain insight into polarization and interface dependent conductivity due to band bending, UV illumination, and chemical reactivity, wedge shaped samples consisting of polar oriented Mg:LN and PE phases were investigated using conductive atomic force microscopy. In Mg:LN, three conductivity states (on/off/transient) were observed under UV illumination, controllable by the polarity of the sample and the externally applied electric field. Measurements of currents originating from electrochemical reactions at the metal electrode-PE phase interfaces demonstrate a memresistive and rectifying capability of the PE phase. Furthermore, internal interfaces such as domain walls and Mg:LN-PE phase boundaries were found to play a major role in the accumulation of charge carriers due to polarization gradients, which can lead to increased currents. The insight gained from these findings yield the potential for multifunctional applications such as switchable UV sensitive micro- and nanoelectronic devices and bistable memristors.

  9. Influence of non-stoichiometric defects on nonlinear absorption and refraction in Nd:Zn co-doped lithium niobate

    NASA Astrophysics Data System (ADS)

    Reddy, J. N. Babu; Elizabeth, Suja; Bhat, H. L.; Venkatram, N.; Rao, D. Narayana

    2009-04-01

    Nonlinear absorption and refraction phenomena in stoichiometric lithium niobate (SLN) pure and co-doped with Zn and Nd, and congruent lithium niobate (CLN) were investigated using Z-scan technique. Femtosecond laser pulses from Ti:Sapphire laser (800 nm, 110 fs pulse width and 1 kHz repetition rate) were utilized for the experiment. The process responsible for nonlinear behavior of the samples was identified to be three photon absorption (3PA). This is in agreement with the band gap energies of the samples obtained from the linear absorption cut off and the slope of the plot of Ln(1 - TOA) vs. Ln( I0) using Sutherland's theory ( s = 2.1, for 3P A). The nonlinear refractive index ( n2) of Zn doped samples was found to be lower than that of pure samples. Our experiments show that there exists a correlation between the nonlinear properties and the stoichiometry of the samples. The values of n2 fall into the same range as those obtained for the materials of similar band gap.

  10. Dynamics of photo-induced changes in the elastic characteristics of lithium niobate crystals doped with Jahn-Teller Fe2+ ions

    NASA Astrophysics Data System (ADS)

    Golenishchev-Kutuzov, A. V.; Golenishchev-Kutuzov, V. A.; Kalimullin, R. I.; Semennikov, A. V.

    2017-02-01

    The effect of admixture Jahn-Teller Fe2+ ions on the elastic characteristics of lithium niobate was studied. The appearance of photostrains and a change in elastic moduli under the influence of laser radiation was established, thus enabling the creation of device elements with optically controlled elastic characteristics.

  11. Alignment nature of ZnO nanowires grown on polished and nanoscale etched lithium niobate surface through self-seeding thermal evaporation method

    SciTech Connect

    Mohanan, Ajay Achath; Parthiban, R.; Ramakrishnan, N.

    2015-08-15

    Highlights: • ZnO nanowires were grown directly on LiNbO{sub 3} surface for the first time by thermal evaporation. • Self-alignment of the nanowires due to step bunching of LiNbO{sub 3} surface is observed. • Increased roughness in surface defects promoted well-aligned growth of nanowires. • Well-aligned growth was then replicated in 50 nm deep trenches on the surface. • Study opens novel pathway for patterned growth of ZnO nanowires on LiNbO{sub 3} surface. - Abstract: High aspect ratio catalyst-free ZnO nanowires were directly synthesized on lithium niobate substrate for the first time through thermal evaporation method without the use of a buffer layer or the conventional pre-deposited ZnO seed layer. As-grown ZnO nanowires exhibited a crisscross aligned growth pattern due to step bunching of the polished lithium niobate surface during the nanowire growth process. On the contrary, scratches on the surface and edges of the substrate produced well-aligned ZnO nanowires in these defect regions due to high surface roughness. Thus, the crisscross aligned nature of high aspect ratio nanowire growth on the lithium niobate surface can be changed to well-aligned growth through controlled etching of the surface, which is further verified through reactive-ion etching of lithium niobate. The investigations and discussion in the present work will provide novel pathway for self-seeded patterned growth of well-aligned ZnO nanowires on lithium niobate based micro devices.

  12. Enhanced second-harmonic generation by means of high-power confinement in a photovoltaic soliton-induced waveguide.

    PubMed

    Lou, Cibo; Xu, Jingjun; Qiao, Haijun; Zhang, Xinzheng; Chen, Yunlin; Chen, Zhigang

    2004-05-01

    We present the first experimental demonstration of enhanced second-harmonic generation (SHG) by means of power confinement with a femtosecond laser in a photovoltaic soliton-induced waveguide. A dark spatial soliton created with a weak cw laser beam in a photovoltaic lithium niobate crystal induces an efficient waveguide for SHG, leading to a 60% enhancement of the conversion efficiency.

  13. Partitioning of ionic species during growth of impurity-doped lithium niobate by electric current injection

    NASA Astrophysics Data System (ADS)

    Nozawa, Jun; Iida, Shintaro; Koyama, Chihiro; Maeda, Kensaku; Fujiwara, Kozo; Koizumi, Haruhiko; Uda, Satoshi

    2014-11-01

    MgO-doped lithium niobate that is simultaneously congruent and stoichiometric, denoted cs-MgO:LN (Li2O:Nb2O5:MgO=45.3:50.0:4.7) [1], has a partition coefficient of unity for each of its constituent species, including ionic species. As such, this material exhibits no segregation of ions during crystal growth. However, a crystallization electromotive force (c-EMF) is observed during growth by the micro-pulling down (μ-PD) method, due to segregation of the cs-MgO:LN ionic species. This arises from a steep temperature gradient at the solid-liquid interface that generates an electric field due to the Seebeck effect. In this case, the equilibrium partition coefficient, k0, must be modified to kE0 to take into account the effect of an electric field on the partitioning of ionic species. A coefficient of kE0 rather than k0 has a value of non-unity and therefore can lead to generation of a c-EMF. An electric current was injected into the melt in such a way that the Seebeck effect was canceled, and this demonstrated that the value of k0 is unity for all constituent ionic species of cs-MgO:LN. It has thus been confirmed that an injected electric current reduces the c-EMF. Only cs-MgO:LN attained a zero c-EMF value at a specific current that was valid at all growth rates, whereas s-MgO(2.5 mol%):LN and ZnO-doped LN required velocity-dependent currents to reduce their c-EMFs to zero. The observation of a zero c-EMF at all growth rates upon removing the Seebeck field effect indicates that the value of k0 is unity for all constituent species of cs-MgO:LN in both the melt and crystal phases, including ionic species. Therefore, the activity of all components of cs-MgO:LN in both phases is unity and this compound is simultaneously stoichiometric and congruent.

  14. Influence of Nd:Zn codoping in near-stoichiometric lithium niobate

    SciTech Connect

    Babu Reddy, J. N.; Ganesh Kamath, K.; Vanishri, S.; Bhat, H. L.; Elizabeth, Suja

    2008-06-28

    Near-stoichiometric lithium niobate (SLN) crystals doped with up to 1.6 mol % Zn and codoped with various Nd concentrations in the melt (0.2, 0.5, 0.9, and 1.5 mol %) (Nd:Zn:SLN) are grown from 58.6 mol % Li{sub 2}O using conventional Czochralski technique. Crystals are pulled at the rate of 0.35 mm/h with seed rotation at 9 rpm. Concentrations of Zn and Nd in the crystal are varied by adding appropriate amounts of ZnO and Nd{sub 2}O{sub 3} to the starting composition. Unit cell parameters of the grown crystals are calculated by Rietveld refinement method using FULLPROFF software. Domain structure studies are carried out by chemical etching followed by microscopic examination. Dielectric studies reveal the existence of piezoelectric resonance at high frequencies. Enhancement in dielectric constant and tan {delta} in Nd doped samples has been attributed to the space charge polarization. Nd doped samples exhibit reduction in the relative permittivity after oxygen annealing. Transmission spectra of Nd:Zn:SLN crystals in the UV region exhibit blueshift in the cutoff wavelength. In Mid Infrared (MIR) region crystals doped with 1.6 mol % Zn have shift in the OH absorption peak from 2873 to 2833 nm. Judd-Ofelt analysis carried out on the absorption spectra of codoped crystal yields the lifetime of 104 {mu}s for the metastable state {sup 4}F{sub 3/2}. The branching ratio for the electronic transition from {sup 4}F{sub 3/2} to {sup 4}I{sub 11/2} is high compared to that for {sup 4}F{sub 3/2} to {sup 4}I{sub 13/2}, indicating a higher emission cross section for the former transition. Laser damage threshold evaluated using 532 nm, 5 ns pulsed neodymium doped yttrium aluminum garnet laser, shows an increase by two orders of magnitude for crystals doped with 1.6 mol % Zn. Photorefractive damage threshold for these crystals shows an enhancement of four orders of magnitude due to increase in the photoconductivity.

  15. Alkaline niobate nanowires as opto-mechanical probes

    NASA Astrophysics Data System (ADS)

    Dutto, Fabrizia; Radenovic, Aleksandra

    2012-10-01

    Perovskite alkaline niobate (XNbO3) nanowires are attracting lots of attention having a variety of interesting properties such as significant nonlinear optical response, pronounced birefringence, considerable piezoelectric, pyroelectric, photorefractive, and photocatalytic response, as well as superior mechanical and chemical stability. Their ability to efficiently generate second harmonic signals (SHG) and their birefringence allow the use of these nanostructures as local mechano-optical probes for single molecule detection. To assess which type of nanowires is suitable for specific application, we performed a comparative study on the nonlinear optical response of the different types of chemically synthesized alkaline niobate nanowires: sodium niobate (NaNbO3), potassium niobate (KNbO3) and lithium niobate (LiNbO3) nanowires. An optical trap setup has been used to demonstrate the possibility to steadily trap the nanowires, their ability to generate high second harmonic signals, to waveguide this signal and to be rotated under a highly focused laser beam with changing polarization. Different applications are suggested for the three materials, such as LiNbO3 nanowires as imaging markers, while KNbO3 and NaNbO3 nanowires for trapping and torque experiments and NaNbO3 nanowires to waveguide SHG light. Functionalization of the XNbO3 nanowires has been studied and successfully implemented. This is a first crucial step toward their use in biomedical imaging and single molecule applications.

  16. Imaging the ultrafast Kerr effect, free carrier generation, relaxation and ablation dynamics of Lithium Niobate irradiated with femtosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Garcia-Lechuga, Mario; Siegel, Jan; Hernandez-Rueda, Javier; Solis, Javier

    2014-09-01

    The interaction of high-power single 130 femtosecond (fs) laser pulses with the surface of Lithium Niobate is experimentally investigated in this work. The use of fs-resolution time-resolved microscopy allows us to separately observe the instantaneous optical Kerr effect induced by the pulse and the generation of a free electron plasma. The maximum electron density is reached 550 fs after the peak of the Kerr effect, confirming the presence of a delayed carrier generation mechanism. We have also observed the appearance of transient Newton rings during the ablation process, related to optical interference of the probe beam reflected at the front and back surface of the ablating layer. Finally, we have analyzed the dynamics of the photorefractive effect on a much longer time scale by measuring the evolution of the transmittance of the irradiated area for different fluences below the ablation threshold.

  17. Agile multicasting based on cascaded χ(2) nonlinearities in a step-chirped periodically poled lithium niobate.

    PubMed

    Ahlawat, Meenu; Bostani, Ameneh; Tehranchi, Amirhossein; Kashyap, Raman

    2013-08-01

    We experimentally demonstrate the possibility of agile multicasting for wavelength division multiplexing (WDM) networks, of a single-channel to two and seven channels over the C band, also extendable to S and L bands. This is based on cascaded χ(2) nonlinear mixing processes, namely, second-harmonic generation (SHG)-sum-frequency generation (SFG) and difference-frequency generation (DFG) in a 20-mm-long step-chirped periodically poled lithium niobate crystal, specially designed and fabricated for a 28-nm-wide SH-SF bandwidth centered at around 1.55 μm. The multiple idlers are simultaneously tuned by detuning the pump wavelengths within the broad SH-SF bandwidth. By selectively tuning the pump wavelengths over less than 10 and 6 nm, respectively, multicasting into two and seven idlers is successfully achieved across ~70 WDM channels within the 50 GHz International Telecommunication Union grid spacing.

  18. Hysteresis-free high-temperature precise bimorph actuators produced by direct bonding of lithium niobate wafers

    NASA Astrophysics Data System (ADS)

    Shur, V. Ya.; Baturin, I. S.; Mingaliev, E. A.; Zorikhin, D. V.; Udalov, A. R.; Greshnyakov, E. D.

    2015-02-01

    The current paper presents a piezoelectric bimorph actuator produced by direct bonding of lithium niobate wafers with the mirrored Y and Z axes. Direct bonding technology allowed to fabricate bidomain plate with precise positioning of ideally flat domain boundary. By optimizing the cutting angle (128° Y-cut), the piezoelectric constant became as large as 27.3 pC/N. Investigation of voltage dependence of bending displacement confirmed that bimorph actuator has excellent linearity and hysteresis-free. Decrease of the applied voltage down to mV range showed the perfect linearity up to the sub-nm deflection amplitude. The frequency and temperature dependences of electromechanical transmission coefficient in wide temperature range (from 300 to 900 K) were investigated.

  19. Periodic disruptions induced by high repetition rate femtosecond pulses on magnesium-oxide-doped lithium niobate surfaces

    NASA Astrophysics Data System (ADS)

    Zhang, Shuanggen; Kan, Hongli; Zhai, Kaili; Ma, Xiurong; Luo, Yiming; Hu, Minglie; Wang, Qingyue

    2017-02-01

    In this paper, we demonstrate the periodic disruption formation on magnesium-oxide-doped lithium niobate surfaces by a femtosecond fiber laser system with wavelength and repetition rate of 1040 nm and 52 MHz, respectively. Three main experimental conditions, laser average power, scanning speed, and orientation of sample were systematically studied. In particular, the ablation morphologies of periodic disruptions under different crystal orientations were specifically researched. The result shows that such disruptions consisting of a bamboo-like inner structure appears periodically for focusing on the surface of X-, Y- and Z-cut wafers, which are formed by a rapid quenching of the material. Meanwhile, due to the anisotropic property, the bamboo-like inner structures consist of a cavity only arise from X- and Z-cut orientation.

  20. Hysteresis-free high-temperature precise bimorph actuators produced by direct bonding of lithium niobate wafers

    SciTech Connect

    Shur, V. Ya.; Baturin, I. S.; Mingaliev, E. A.; Zorikhin, D. V.; Udalov, A. R.; Greshnyakov, E. D.

    2015-02-02

    The current paper presents a piezoelectric bimorph actuator produced by direct bonding of lithium niobate wafers with the mirrored Y and Z axes. Direct bonding technology allowed to fabricate bidomain plate with precise positioning of ideally flat domain boundary. By optimizing the cutting angle (128° Y-cut), the piezoelectric constant became as large as 27.3 pC/N. Investigation of voltage dependence of bending displacement confirmed that bimorph actuator has excellent linearity and hysteresis-free. Decrease of the applied voltage down to mV range showed the perfect linearity up to the sub-nm deflection amplitude. The frequency and temperature dependences of electromechanical transmission coefficient in wide temperature range (from 300 to 900 K) were investigated.

  1. Point imperfections and clusters of intrinsic and extrinsic defects in non-stoichiometric and stoichiometric lithium niobate

    NASA Astrophysics Data System (ADS)

    Malovichko, G.; Grachev, V.; Kokanyan, E.; Schirmer, O.

    The results of our investigations of different kinds of defects in lithium niobate crystals are summarized in this report. Randomly distributed intrinsic point imperfections are dominating in conventional congruent crystals. This leads to a perturbation of the surroundings of optically or acoustically active impurities and to a broadening of their spectral lines. The great narrowing of resonance lines in nearly stoichiometric samples increases the spectral resolution sufficiently to allow the study of even non-controlled trace impurities and satellite centers, consisting of the impurity and intrinsic defects. The disappearance of satellite centers and the appearance of new centers due to the change of charge compensation mechanism was discovered in stoichiometric crystals. The quantitative characterization of the degree of crystal perfection, a definition of regularly ordered crystal and the necessity of the re-investigation of physical properties for perfect samples are discussed.

  2. A novel auto-bias control scheme for stabilizing lithium niobate Mach-Zehnder modulator at any operating point

    NASA Astrophysics Data System (ADS)

    Tao, Jin-jing; Zhang, Yang-an; Zhang, Jin-nan; Yuan, Xue-guang; Huang, Yong-qing; Li, Yu-peng

    2014-01-01

    In this paper, we propose and experimentally demonstrate an auto-bias control scheme for stabilizing a lithium niobate (LN) Mach-Zehnder modulator (MZM) at any operating point along the power transmission curve. It is based on that the bias drift would change the operating point and result in varying the output optical average power of the Mach-Zehnder modulator and its first and second derivatives. The ratio of the first to the second derivative of the output optical average power is used in the proposed scheme as the key parameter. The experimental results show that the output optical average power of the LN MZM hardly changes at the desired operating point, and the maximum deviation of output optical average power is less than ±4%.

  3. Imaging the ultrafast Kerr effect, free carrier generation, relaxation and ablation dynamics of Lithium Niobate irradiated with femtosecond laser pulses

    SciTech Connect

    Garcia-Lechuga, Mario Siegel, Jan Hernandez-Rueda, Javier; Solis, Javier

    2014-09-21

    The interaction of high-power single 130 femtosecond (fs) laser pulses with the surface of Lithium Niobate is experimentally investigated in this work. The use of fs-resolution time-resolved microscopy allows us to separately observe the instantaneous optical Kerr effect induced by the pulse and the generation of a free electron plasma. The maximum electron density is reached 550 fs after the peak of the Kerr effect, confirming the presence of a delayed carrier generation mechanism. We have also observed the appearance of transient Newton rings during the ablation process, related to optical interference of the probe beam reflected at the front and back surface of the ablating layer. Finally, we have analyzed the dynamics of the photorefractive effect on a much longer time scale by measuring the evolution of the transmittance of the irradiated area for different fluences below the ablation threshold.

  4. NONLINEAR OPTICAL PHENOMENA: Manifestation of a photorefractive effect in Raman spectra of lithium niobate crystals of different compositions

    NASA Astrophysics Data System (ADS)

    Sidorov, N. V.; Chufyrev, P. G.; Palatnikov, M. N.; Mel'nik, N. N.; Zheleznov, Yu A.; Khomich, V. Yu

    2004-12-01

    The ordering of structural units in a cation sublattice and the photorefractive properties of lithium niobate single crystals of different compositions: nominally pure with different [Li]/[Nb] ratios and doped with non-photorefractive cations Mg2+, Gd3+, and Y3+, are studied by their Raman spectra. It is shown that at low concentrations of Mg2+, Gd3+, and Y3+, the magnitude of the photorefractive effect is determined by the ordering of the structural units of the cation sublattice. It is found for the first time that the intensity of a Raman line corresponding to the bridge valence vibrations of oxygen atoms in the NbO6 octahedra is sensitive to the dipole ordering of the cation sublattice.

  5. Second-harmonic generation in single-mode integrated waveguides based on mode-shape modulation

    NASA Astrophysics Data System (ADS)

    Rao, Ashutosh; Chiles, Jeff; Khan, Saeed; Toroghi, Seyfollah; Malinowski, Marcin; Camacho-González, Guillermo Fernando; Fathpour, Sasan

    2017-03-01

    Second-harmonic generation is demonstrated using grating-assisted quasi-phase matching, based on waveguide-width modulation or mode-shape modulation. Applicable to any thin-film integrated second-order nonlinear waveguide, the technique is demonstrated in compact lithium niobate ridge waveguides. Fabricated devices are characterized with pulsed-pumping in the near-infrared, showing second-harmonic generation at a signal wavelength of 784 nm and propagation loss of 1 dB/cm.

  6. Planar optical waveguide in Cu-doped potassium sodium strontium barium niobate crystal formed by mega-electron-volt He-ion implantation.

    PubMed

    Lu, F; Meng, M Q; Wang, K M; Liu, X D; Chen, H C; Shen, D Y

    1997-02-01

    The first planar optical waveguide to the authors' knowledge has been formed in Cu-doped potassium sodium strontium barium niobate crystal by mega-electron-volt He(+) implantation. Both TE and TM modes are observed. The profiles of the ordinary and the extraordinary refractive indices are deduced from dark-line mode spectroscopy. The results show that the mega-electron-volt He implantation results in a decrease in refractive index in barriers for both n(o) and n(e), but for n(e) there is an obvious increase in the waveguide region. From an experiment in photorefractive two-wave mixing, it is found that the erasure time for two-wave mixing is prolonged by ion implantation.

  7. High-energy (100-keV) e-beam lithography applied for fabrication of deep-submicrometer SAW devices on lithium niobate and quartz

    NASA Astrophysics Data System (ADS)

    Kondek, Christine A.; Poli, Louis C.

    1995-05-01

    Fabricating submicron feature size Surface Acoustic Wave (SAW) devices on Lithium Niobate and Quartz allows one to take advantage of their unique piezoelectric material properties and operate at higher frequencies. With the recent availability of high performance, high energy e-beam nanowriter tools such as the Leica/Phillips EBPG-HR5 resident at this facility, SAW devices with very narrow line/space transducer gratings can be investigated. Utilizing very high energy (100 keV) direct write electron beam lithography (EBL), allows for processing of deep submicron features with an associated wider process latitude. This is specially desirable when applying EBL to high average Z materials such as lithium niobate. A previously presented paper demonstrated 400 and 500 nm line/space interdigitated transducer fingers on quartz and lithium niobate substrates. E-Beam lithography (30 keV) was used with two and three level, positive and negative tone processes respectively. In this current work a bilevel positive tone process is used by the authors, and involves first spinning a preparation of (1:1) ZEP-320-37 (Nagase Chemical) positive e-beam resist. A commercially available conductive polymer known as TQV-501 (Nitto Chemical) is then spun onto the wafer and serves as a charge removal vehicle. The TQV-501 film is removed by the development procedure. Xylene is used as the developer. Contact pads and interdigitated transducer elements are realized by e-beam metal deposition and lift off process. We will show a direct write positive tone process for the fabrication of deep submicron (400 nM and smaller) interdigitated transducer gratings on Lithium Niobate and Quartz substrates. An improved process dose latitude is seen because of the reduced expected proximity effect at high beam energy.

  8. Tip-induced domain growth on the non-polar cuts of lithium niobate single-crystals

    SciTech Connect

    Alikin, D. O.; Turygin, A. P.; Lobov, A. I.; Shur, V. Ya.; Ievlev, A. V.; Kalinin, S. V.

    2015-05-04

    Currently, ferroelectric materials with designed domain structures are considered as a perspective material for new generation of photonic, data storage, and data processing devices. Application of external electric field is the most convenient way of the domain structure formation. Lots of papers are devoted to the investigation of domain kinetics on polar surface of crystals while the forward growth remains one of the most mysterious stages due to lack of experimental methods allowing to study it. Here, we performed tip-induced polarization reversal on X- and Y-non-polar cuts in single-crystal of congruent lithium niobate which allows us to study the forward growth with high spatial resolution. The revealed difference in the shape and length of domains induced on X- and Y-cuts is beyond previously developed theoretical approaches used for the theoretical consideration of the domains growth at non-polar ferroelectric surfaces. To explain experimental results, we used kinetic approach with anisotropy of screening efficiency along different crystallographic directions.

  9. Tip-induced domain growth on the non-polar cuts of lithium niobate single-crystals

    SciTech Connect

    Alikin, Denis O.; Ievlev, Anton; Turigin, Anton P.; Lobov, Alexei; Kalinin, Sergei V; Shur, Vladimir Ya.

    2015-05-05

    Currently ferroelectric materials with designed domain structures are considered as a perspective material for new generation of photonic, data storage and data processing devices. Application of external electric field is the most convenient way of the domain structure formation. Lots of papers are devoted to investigation of the domain kinetics on polar surface of crystals while the forward growth remains one of the most mysterious stages due to lack of experimental methods allowing to study it. Here we performed tip-induced polarization reversal on X- and Y-non-polar cuts in single-crystal of congruent lithium niobate allows us to study the forward growth with high spatial resolution. The revealed difference in the shape and length of domains induced on X- and Y-cuts is beyond previously developed theoretical approaches used for the theoretical consideration of the domains growth at non-polar ferroelectric surfaces. Lastly, to explain experimental results we used kinetic approach with anisotropy of screening efficiency along different crystallographic directions.

  10. Tip-induced domain growth on the non-polar cuts of lithium niobate single-crystals

    DOE PAGES

    Alikin, Denis O.; Ievlev, Anton; Turigin, Anton P.; ...

    2015-05-05

    Currently ferroelectric materials with designed domain structures are considered as a perspective material for new generation of photonic, data storage and data processing devices. Application of external electric field is the most convenient way of the domain structure formation. Lots of papers are devoted to investigation of the domain kinetics on polar surface of crystals while the forward growth remains one of the most mysterious stages due to lack of experimental methods allowing to study it. Here we performed tip-induced polarization reversal on X- and Y-non-polar cuts in single-crystal of congruent lithium niobate allows us to study the forward growthmore » with high spatial resolution. The revealed difference in the shape and length of domains induced on X- and Y-cuts is beyond previously developed theoretical approaches used for the theoretical consideration of the domains growth at non-polar ferroelectric surfaces. Lastly, to explain experimental results we used kinetic approach with anisotropy of screening efficiency along different crystallographic directions.« less

  11. The impact of MgO-doped near-stoichiometric lithium niobate crystals on the THz wave output characteristics

    NASA Astrophysics Data System (ADS)

    Xianbin, Zhang; Yunfeng, Li; lijuan, Ma; ke, Yuan; Wei, Shi

    2011-02-01

    The control experimental study on the THz wave parametric oscillator (TPO) output characteristics based on the congruent LiNbO3 crystal (CLN) and stoichiometric MgO-doped lithium niobate (SLN) crystal is performed. As a nonlinear medium in the aspect of the THz wave output experiments show that the congruent LiNbO3 crystal is more stable than the SLN crystal. Compared with the CLN crystal SLN showed significant photorefractive effect which adversely the stability of the THz wave output. Experiments indicated that different molar concentration of MgO doped can significantly change the photorefractive properties of SLN crystal. The results showed that with the increase of MgO doping concentration the photorefractive of SLN gradually become weaker and THz wave output stability has the significantly increase. The output stability of mol 5.0% MgO droped SLN crystal has not significantly different with the CLN. In the contrast experiment of TPO with the 160mm cavity length and 65mm crystal length the pump laser threshold of the 5% mol MgO: SLN crystal decreased by 23% than the CLN crystal while the peak THz energy output increased 28%.

  12. Interlinked add-drop filter with amplitude modulation routing a fiber-optic microring to a lithium niobate microwaveguide.

    PubMed

    Zhou, Suxu; Dong, Jiangli; He, Donghui; Wang, Yuan; Qiu, Wentao; Yu, Jianhui; Guan, Heyuan; Zhu, Wenguo; Zhong, Yongchun; Luo, Yunhan; Zhang, Jun; Chen, Zhe; Lu, Huihui

    2017-04-15

    We propose and experimentally demonstrate a new electro-optically controllable add-drop filter based on light coupling between a microfiber knot ring (MKR) and a lithium niobate (LN) microwaveguide. In our design, the MKR works as a resonator and routes the resonant light into the LN microwaveguide. The LN microwaveguide, as an excellent intermediary between electronics and optics, is a robust platform that not only enables stable support and manipulation of the MKR but also provides amplitude tunability taking advantage of its electro-optic property. Two add-drop filters with different diameters of the MKR, 1.12 mm, and 560 μm respectively, are studied, and a maximum amplitude tunability of ∼0.139  dB/V is obtained. The results show that this design can be a solution to interconnect a microstructured optical fiber with a microstructured on-chip device and provide an effective method to realize the active on-chip integration of the conventional fiber system.

  13. Highly efficient flexible piezoelectric nanogenerator and femtosecond two-photon absorption properties of nonlinear lithium niobate nanowires

    NASA Astrophysics Data System (ADS)

    Gupta, Manoj Kumar; Aneesh, Janardhanakurup; Yadav, Rajesh; Adarsh, K. V.; Kim, Sang-Woo

    2017-05-01

    We present a high performance flexible piezoelectric nanogenerator (NG) device based on the hydrothermally grown lead-free piezoelectric lithium niobate (LiNbO3) nanowires (NWs) for scavenging mechanical energies. The non-linear optical coefficient and optical limiting properties of LiNbO3 were analyzed using femtosecond laser pulse assisted two photon absorption techniques for the first time. Further, a flexible hybrid type NG using a composite structure of the polydimethylsiloxane polymer and LiNbO3 NWs was fabricated, and their piezoelectric output signals were measured. A large output voltage of ˜4.0 V and a recordable large current density of about 1.5 μA cm-2 were obtained under the cyclic compressive force of 1 kgf. A subsequent UV-Vis analysis of the as-prepared sample provides a remarkable increase in the optical band gap (UV absorption cut-off, ˜251 nm) due to the nanoscale size effect. The high piezoelectric output voltage and current are discussed in terms of large band gap, significant nonlinear optical response, and electric dipole alignments under poling effects. Such high performance and unique optical properties of LiNbO3 show its great potential towards various next generation smart electronic applications and self-powered optoelectronic devices.

  14. Substitution mechanisms and location of Co2+ ions in congruent and stoichiometric lithium niobate crystals derived from electron paramagnetic resonance data

    NASA Astrophysics Data System (ADS)

    Grachev, V. G.; Hansen, K.; Meyer, M.; Kokanyan, E. P.; Malovichko, G. I.

    2017-03-01

    Electron paramagnetic resonance (EPR) spectra and their angular dependencies were measured for Co2+ trace impurities in stoichiometric samples of lithium niobate doped with rhodium. It was found that Co2+ substitutes for Li+ in the dominant axial center (CoLi) and that the principal substitution mechanism in stoichiometric lithium niobate is 4Co2+ ↔ 3Li+  +  Nb5+. The four Co2+ ions can occupy the nearest possible cation sites by occupying a Nb site and its three nearest-neighbor Li sites, creating a trigonal pyramid with C3 symmetry, as well as non-neighboring sites (e.g. a CoNb-CoLi pair at the nearest sites on the C3 axis with two nearby isolated single Co2+ ions substituted for Li+). In congruent crystals and samples with Li content enriched by vapor transport equilibrium treatment the excess charge of the Co2+ centers is compensated by lithium vacancies located rather far from the Co2+ ions for the dominant axial center or in the nearest neighborhood for low-symmetry satellite centers (the Co2+ ↔ 2Li+ substitution mechanism). The use of exact numerical diagonalization of the spin-Hamiltonian matrices explains all the details of the EPR spectra and gives a value for hyperfine interaction A || that is several times smaller than that obtained using perturbation formulae. The refined values of A and g-tensor components can be used as reliable cornerstones for ab initio and cluster calculations.

  15. Modelling of Optical Guided Wave Devices in Lithium Niobate Using Test Structures for Process Characterization

    NASA Astrophysics Data System (ADS)

    Wooten, Eddie Lynn

    This dissertation presents a study of the modelling of optical guided wave devices in LiNbO_3 with emphasis on experimental verification of the models. The goals are to identify the main sources of error in the modelling process, construct a model capable of achieving qualitative and quantitative accuracy, and develop a method of determining the correct set of input parameters to the model for a given fabrication process. The investigation is limited to mode interference type devices and the switching voltage is used as a basis for comparison. The finite element method is used for calculation of optical modes in waveguides with graded refractive index profiles. The integral equation method is used for calculation of the static electric field due to electrodes in a three layer anisotropic structure. It is proposed that the main source of error in the modelling process is not in the model itself, but in determining the correct input parameters to the model. The investigation of the input parameters focusses on a priori knowledge of the parameters and the sensitivity of the model to each parameter. The five parameters responsible for the largest errors in Ti:LiNbO_3 devices are identified as the Ti diffusion coefficients, the peak index change in the waveguides, the electrooptic coefficient, and the buffer layer dielectric constant. A method is presented for determining each of the selected parameters using a set of test devices fabricated on a single chip. The test set includes a planar waveguide, Mach-Zehnder modulators, and symmetrically perturbed directional couplers. Several sets of these devices have been fabricated using different fabrication conditions. The parameter values determined using this method compare favorably to those reported in the literature. The diffusion of Ti for x-cut crystals is found to be highly anisotropic, with the lateral diffusion length being about twice as large as the diffusion depth. The dependence of the diffusion lengths on

  16. Origin of UV-induced poling inhibition in lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Steigerwald, H.; Lilienblum, M.; von Cube, F.; Ying, Y. J.; Eason, R. W.; Mailis, S.; Sturman, B.; Soergel, E.; Buse, K.

    2010-12-01

    Short-term exposure of the +z face of LiNbO3 crystals to focused UV laser light leads to persistent inhibition of ferroelectric domain reversal at the irradiated area, a phenomenon referred to as “poling inhibition.” Different types of crystals (stoichiometric, congruent, or Mg-doped ones) are exposed, creating the so-called “latent state” and domain growth during subsequent electric-field poling is visualized. The latent state is robust against thermal annealing up to 250°C and uniform illumination. With the tip of a scanning force microscope the coercive field is mapped, showing not only the expected resistance against domain reversal in the UV-irradiated region but also easier poling adjacent to the UV-irradiated section. These results and theoretical estimates point to the following mechanism of poling inhibition: the UV light-induced heating results in a local reduction of the lithium concentration, via thermodiffusion. The required charge compensation is provided by UV-excited free electrons/holes. After cooling, the lithium ions become immobile, and the reduced lithium concentration causes a strong local increase in the coercive field in the exposed area, while the increased Li concentration next to this area reduces the coercive field.

  17. Supercontinuum Generation in Lithium Niobate Ridge Waveguides Fabricated by Proton Exchange and Ion Beam Enhanced Etching

    NASA Astrophysics Data System (ADS)

    Xiang, Bing-Xi; Wang, Lei; Ma, Yu-Jie; Yu, Li; Han, Huang-Pu; Ruan, Shuang-Chen

    2017-02-01

    Not Available Supported by the National Natural Science Foundation of China under Grant Nos 61575129 and 11375105, the Postdoctoral Science Foundation of China under Grant No 2016M602511, the Shenzhen Science and Technology Planning under Grant No JCYJ20160422142912923, and the State Key Laboratory of Nuclear Physics and Technology, Peking University.

  18. Manufacture and cytotoxicity of a lead-free piezoelectric ceramic as a bone substitute-consolidation of porous lithium sodium potassium niobate by cold isostatic pressing.

    PubMed

    Wang, Qi; Yang, Jun; Zhang, Wu; Khoie, Roxanne; Li, Yi-Ming; Zhu, Jian-Guo; Chen, Zhi-Qing

    2009-06-01

    The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Cold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague-Dawley rats were examined by a scanning electron microscopy (SEM) and methylthiazol tetrazolium (MTT) assay. The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute.

  19. Manufacture and Cytotoxicity of a Lead-free Piezoelectric Ceramic as a Bone Substitute—Consolidation of Porous Lithium Sodium Potassium Niobate by Cold Isostatic Pressing

    PubMed Central

    Wang, Qi; Yang, Jun; Zhang, Wu; Khoie, Roxanne; Li, Yi-ming; Zhu, Jian-guo; Chen, Zhi-qing

    2009-01-01

    Aim The piezoelectric properties and cytotoxicity of a porous lead-free piezoelectric ceramic for use as a direct bone substitute were investigated. Methodology Cold isostatic pressing (CIP) was applied to fabricate porous lithium sodium potassium niobate (Li0.06Na0.5K0.44) NbO3 specimens using a pore-forming method. The morphologies of the CIP-processed specimens were characterized and compared to those of specimens made by from conventional pressing procedures. The effects of the ceramic on the attachment and proliferation of osteoblasts isolated from the cranium of 1-day-old Sprague-Dawley rats were examined by a scanning electron microscopy (SEM) and methylthiazol tetrazolium (MTT) assay. Results The results showed that CIP enhanced piezoelectricity and biological performance of the niobate specimen, and also promoted an extracellular matrix-like topography of it. In vitro studies showed that the CIP-enhanced material had positive effects on the attachment and proliferation of osteoblasts. Conclusion Niobate ceramic generated by CIP shows a promise for being a piezoelectric composite bone substitute. PMID:20687302

  20. Optimization of the idler wavelength tunable cascaded optical parametric oscillator based on chirp-assisted aperiodically poled lithium niobate crystal

    NASA Astrophysics Data System (ADS)

    Tao, Chen; Rong, Shu; Ye, Ge; Zhuo, Chen

    2016-01-01

    We present the numerical results for the optimization of the pump-to-idler conversion efficiencies of nanosecond idler wavelength tunable cascaded optical parametric oscillators (OPO) in different wavelength tuning ranges, where the primary signals from the OPO process are recycled to enhance the pump-to-idler conversion efficiencies via the simultaneous difference frequency generation (DFG) process by monolithic aperiodically poled, magnesium oxide doped lithium niobate (APMgLN) crystals. The APMgLN crystals are designed with different chirp parameters for the DFG process to broaden their thermal acceptance bandwidths to different extents. The idler wavelength tuning of the cascaded OPO is realized by changing the temperature of the designed APMgLN crystal and the cascaded oscillation is achieved in a single pump pass singly resonant linear cavity. The pump-to-idler conversion efficiencies with respect to the pump pulse duration and ratio of OPO coefficient to DFG coefficient are calculated by numerically solving the coupled wave equations. The optimal working conditions of the tunable cascaded OPOs pumped by pulses with energies of 350 μJ and 700 μJ are compared to obtain the general rules of optimization. It is concluded that the optimization becomes the interplay between the ratio of OPO coefficient to DFG coefficient and the pump pulse duration when the idler wavelength tuning range and the pump pulse energy are fixed. Besides, higher pump pulse energy is beneficial for reaching higher optimal pump-to-idler conversion efficiency as long as the APMgLN crystal is optimized according to this pump condition. To the best of our knowledge, this is the first numerical analysis of idler wavelength tunable cascaded OPOs based on chirp-assisted APMgLN crystals. Project supported by the National Natural Science Foundation of China (Grant No. 61505236), the Innovation Program of Shanghai Institute of Technical Physics, China (Grant No. CX-2), and the Program of Shanghai

  1. Optical properties of titanium-doped lithium niobate from time-dependent density-functional theory

    NASA Astrophysics Data System (ADS)

    Friedrich, Michael; Schmidt, W. G.; Schindlmayr, Arno; Sanna, Simone

    2017-08-01

    The optical properties of pristine and titanium-doped LiNbO3 are modeled from first principles. The dielectric functions are calculated within time-dependent density-functional theory, and a model long-range contribution is employed for the exchange-correlation kernel in order to account for the electron-hole binding. Our study focuses on the influence of substitutional titanium atoms on lithium sites. We show that an increasing titanium concentration enhances the values of the refractive indices and the reflectivity.

  2. Modified sol-gel method for patterned lithium niobate thin film preparation

    NASA Astrophysics Data System (ADS)

    Poghosyan, Armen R.; Guo, Ruyan; Grigoryan, Stepan G.; Manukyan, Aleksandr L.; Vardanyan, Eduard S.

    2008-08-01

    A key stage in production of the integrated optics devices is forming of microtopography on crystalline films. The current methods generally comprise two separate steps: producing of thin film and creation a topographical pattern on it. But the inherently large chemical stability of crystalline LiNbO3 has effectively precluded the use of standard photolithographic patterning techniques. We present new approach based on the modified sol-gel technology using the photosensitive gel. In this case, the photolithography is used on the stage of dried gel whereupon the direct crystallization of patterned precursor film allows to create integrated optical element without subsequent etching of crystalline film. Presented method of patterned thin film preparation involves synthesis of photo-reactive complex of metal, which undergoes change under the UV light. This technology has allowed to obtain first samples of different types of waveguide devices.

  3. Electric field-induced strain behavior in lithium- and copper-added potassium sodium niobate piezoceramics and 1-3 piezocomposites.

    PubMed

    Alkoy, Ebru Mensur; Berksoy, Ayse; Tekdas, A Serkan

    2011-09-01

    Potassium sodium niobate (KNN)-based leadfree materials were prepared and their field-induced strain behaviors were investigated. Ceramic lead-free piezoelectric materials were prepared in bulk and fiber forms with 1 mol% CuO-added potassium sodium niobate K0.5Na0.5NbO3 and x = 7 mol% lithium-modified (K(0.5-x/2)Na(0.5-x/2)Li(x))NbO(3) compositions. Fibers were drawn using a novel alginate gelation technique. Piezocomposites were prepared from these fibers with 1-3 connectivity and an epoxy matrix. A fully recoverable electrostrain of up to approximately 0.11% was observed in the CuO-added sample, whereas the Li-modified sample yielded up to 0.10% at 50 kV/cm electric field. A strain value of up to approximately 0.03% at 50 kV/cm electric field was obtained for piezocomposites prepared from lithium-modified fibers. The high-field converse piezoelectric coefficient was calculated from the strain-electric field (x-E) graph for all samples. Strain characteristics of the bulk and piezocomposite samples were analyzed based on the variation of strain with respect to square of the polarization (x-P2) to determine the electrostrictive contribution to the strain.

  4. Are lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) ferroelectrics bioactive?

    PubMed

    Vilarinho, Paula Maria; Barroca, Nathalie; Zlotnik, Sebastian; Félix, Pedro; Fernandes, Maria Helena

    2014-06-01

    The use of functional materials, such as ferroelectrics, as platforms for tissue growth in situ or ex situ, is new and holds great promise. But the usage of materials in any bioapplication requires information on biocompatibility and desirably on bioactive behavior when bone tissue engineering is envisaged. Both requirements are currently unknown for many ferroelectrics. Herein the bioactivity of LiNbO3 and LiTaO3 is reported. The formation of apatite-like structures on the surface of LiNbO3 and LiTaO3 powders after immersion in simulated body fluid (SBF) for different soaking periods indicates their bioactive potential. The mechanism of apatite formation is suggested. In addition, the significant release of lithium ions from the ferroelectric powders in the very first minutes of soaking in SBF is examined and ways to overcome this likely hurdle addressed.

  5. FABRICATION AND TESTING OF MICROWAVE SINTERED SOL-GEL SPRAY-ON BISMUTH TITANATE-LITHIUM NIOBATE BASED PIEZOELECTRIC COMPOSITE FOR USE AS A HIGH TEMPERATURE (>500 deg. C) ULTRASONIC TRANSDUCER

    SciTech Connect

    Searfass, C. T.; Baba, A.; Tittmann, B. R.; Agrawal, D. K.

    2010-02-22

    Bismuth titanate-lithium niobate based ultrasonic transducers have been fabricated using a sol-gel spray-on deposition technique. These transducers were then tested to determine their potential as high temperature ultrasonic transducers. Fabricated transducers were capable of operating to 1000 deg. C in pulse-echo mode; however, the exposure to such extreme temperatures appears to be destructive to the transducers.

  6. Waveguide structures in anisotropic nonlinear crystals

    NASA Astrophysics Data System (ADS)

    Li, Da; Hong, Pengda; Meissner, Helmuth E.

    2017-02-01

    We report on the design and manufacturing parameters of waveguiding structures of anisotropic nonlinear crystals that are employed for harmonic conversions, using Adhesive-Free Bonding (AFB®). This technology enables a full range of predetermined refractive index differences that are essential for the design of single mode or low-mode propagation with high efficiency in anisotropic nonlinear crystals which in turn results in compact frequency conversion systems. Examples of nonlinear optical waveguides include periodically bonded walk-off corrected nonlinear optical waveguides and periodically poled waveguide components, such as lithium triborate (LBO), beta barium borate (β-BBO), lithium niobate (LN), potassium titanyl phosphate (KTP), zinc germanium phosphide (ZGP) and silver selenogallate (AGSE). Simulation of planar LN waveguide shows that when the electric field vector E lies in the k-c plane, the power flow is directed precisely along the propagation direction, demonstrating waveguiding effect in the planar waveguide. Employment of anisotropic nonlinear optical waveguides, for example in combination with AFB® crystalline fiber waveguides (CFW), provides access to the design of a number of novel high power and high efficiency light sources spanning the range of wavelengths from deep ultraviolet (as short as 200 nm) to mid-infrared (as long as about 18 μm). To our knowledge, the technique is the only generally applicable one because most often there are no compatible cladding crystals available to nonlinear optical cores, especially not with an engineer-able refractive index difference and large mode area.

  7. Field induced modification of defect complexes in magnesium-doped lithium niobate

    SciTech Connect

    Meyer, Nadège; Granzow, Torsten; Nataf, Guillaume F.

    2014-12-28

    Dielectric constant, thermally stimulated depolarization currents (TSDC), and conductivity of undoped and 5% Mg-doped LiNbO{sub 3} single crystals between −100 °C and 200 °C have been investigated. A Debye-like dielectric relaxation with an activation energy of 135 meV is observed in the Mg-doped material, but not in undoped crystals. On heating this relaxation disappears near 140 °C and does not reappear after cooling. Anomalies observed in TSDC around this temperature are attributed to the motion of lithium vacancies, in agreement with conductivity measurements. It is proposed that in thermal equilibrium the electrons from the Mg{sub Li}{sup •} donors are trapped in (4Mg{sub Li}{sup •}+4V{sub Li}{sup ′}) defect complexes. High-temperature poling breaks these defect complexes. The transition of the liberated electrons between the Mg{sub Li}{sup •} donor centers and the Nb{sub Nb} forming the conduction band gives rise to the observed dielectric relaxation.

  8. Comparative study of 0° X-cut and Y+36°-cut lithium niobate high-voltage sensing

    DOE PAGES

    Patel, N.; Branch, D. W.; Schamiloglu, E.; ...

    2015-08-11

    A comparison study between Y+36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y+36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to bothmore » crystals, the voltage-induced shift scaled linearly with voltage. For the Y+36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz–100 kHz. Using the same conditions as the Y+36° cut, the 0° X-cut crystal sensed a shift of 10–273 ps for DC voltages and 189–813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250–2 ns and the Y+36°-cut crystal sensed a time shift of 0.115–1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. Furthermore, when the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.« less

  9. Comparative study of 0° X-cut and Y+36°-cut lithium niobate high-voltage sensing

    SciTech Connect

    Patel, N.; Branch, D. W.; Schamiloglu, E.; Cular, S.

    2015-08-11

    A comparison study between Y+36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y+36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y+36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz–100 kHz. Using the same conditions as the Y+36° cut, the 0° X-cut crystal sensed a shift of 10–273 ps for DC voltages and 189–813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250–2 ns and the Y+36°-cut crystal sensed a time shift of 0.115–1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. Furthermore, when the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

  10. Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing.

    PubMed

    Patel, N; Branch, D W; Schamiloglu, E; Cular, S

    2015-08-01

    A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz-100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10-273 ps for DC voltages and 189-813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250-2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115-1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

  11. Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

    SciTech Connect

    Patel, N.; Branch, D. W.; Cular, S.; Schamiloglu, E.

    2015-08-15

    A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO{sub 3}) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz–100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10–273 ps for DC voltages and 189–813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250–2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115–1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

  12. Comparative study of 0° X-cut and Y + 36°-cut lithium niobate high-voltage sensing

    NASA Astrophysics Data System (ADS)

    Patel, N.; Branch, D. W.; Schamiloglu, E.; Cular, S.

    2015-08-01

    A comparison study between Y + 36° and 0° X-cut lithium niobate (LiNbO3) was performed to evaluate the influence of crystal cut on the acoustic propagation to realize a piezoelectric high-voltage sensor. The acoustic time-of-flight for each crystal cut was measured when applying direct current (DC), alternating current (AC), and pulsed voltages. Results show that the voltage-induced shift in the acoustic wave propagation time scaled quadratically with voltage for DC and AC voltages applied to X-cut crystals. For the Y + 36° crystal, the voltage-induced shift scales linearly with DC voltages and quadratically with AC voltages. When applying 5 μs voltage pulses to both crystals, the voltage-induced shift scaled linearly with voltage. For the Y + 36° cut, the voltage-induced shift from applying DC voltages ranged from 10 to 54 ps and 35 to 778 ps for AC voltages at 640 V over the frequency range of 100 Hz-100 kHz. Using the same conditions as the Y + 36° cut, the 0° X-cut crystal sensed a shift of 10-273 ps for DC voltages and 189-813 ps for AC voltage application. For 5 μs voltage pulses, the 0° X-cut crystal sensed a voltage induced shift of 0.250-2 ns and the Y + 36°-cut crystal sensed a time shift of 0.115-1.6 ns. This suggests a frequency sensitive response to voltage where the influence of the crystal cut was not a significant contributor under DC, AC, or pulsed voltage conditions. The measured DC data were compared to a 1-D impedance matrix model where the predicted incremental length changed as a function of voltage. When the voltage source error was eliminated through physical modeling from the uncertainty budget, the combined uncertainty of the sensor (within a 95% confidence interval) decreased to 0.0033% using a Y + 36°-cut crystal and 0.0032% using an X-cut crystal for all the voltage conditions used in this experiment.

  13. Piezoelectric and ferroelectric properties of lead-free niobium-rich potassium lithium tantalate niobate single crystals

    SciTech Connect

    Li, Jun; Li, Yang; Zhou, Zhongxiang; Guo, Ruyan; Bhalla, Amar S.

    2014-01-01

    Graphical abstract: - Highlights: • Lead-free K{sub 0.95}Li{sub 0.05}Ta{sub 1−x}Nb{sub x}O{sub 3} single crystals were grown using the top-seeded melt growth method. • The piezoelectric and ferroelectric properties of as-grown crystals were systematically investigated. • The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ≈ 70%, k{sub 31} ≈ 70%, k{sub 33} ≈ 77%, d{sub 31} ≈ 230 pC/N, d{sub 33} ≈ 600 pC/N. • The coercive fields of P–E hysteresis loops are quite small, about or less than 1 kV/mm. - Abstract: Lead-free potassium lithium tantalate niobate single crystals with the composition of K{sub 0.95}Li{sub 0.05}Ta{sub 1−x}Nb{sub x}O{sub 3} (abbreviated as KLTN, x = 0.51, 0.60, 0.69, 0.78) were grown using the top-seeded melt growth method. Their piezoelectric and ferroelectric properties in as-grown crystals have been systematically investigated. The phase transitions and Curie temperatures were determined from dielectric and pyroelectric measurements. Piezoelectric coefficients and electromechanical coupling factors in thickness mode, length-extensional mode and longitudinal mode were obtained. The piezoelectric properties are very attractive, e.g. for x = 0.60 composition, k{sub t} ≈ 70%, k{sub 31} ≈ 70%, k{sub 33} ≈ 77%, d{sub 31} ≈ 230 pC/N, d{sub 33} ≈ 600 pC/N are comparable to the lead-based PZT composition. The polarization versus electric field hysteresis loops show saturated shapes. In short, lead-free niobium-rich KLTN system possesses comparable properties to those in important lead-based piezoelectric material nowadays.

  14. Progress in fabrication of waveguide spatial light modulators via femtosecond laser micromachining

    NASA Astrophysics Data System (ADS)

    Savidis, Nickolaos; Jolly, Sundeep; Datta, Bianca; Moebius, Michael; Karydis, Thrasyvoulos; Mazur, Eric; Gershenfeld, Neil; Bove, V. Michael

    2017-02-01

    We have previously introduced a femtosecond laser micromachining-based scheme for the fabrication of anisotropic waveguides in lithium niobate for use in a guided-wave acousto-optic spatial light modulator. This spatial light modulation scheme is extensible to off-plane waveguide holography via the integration of a Bragg reflection grating. In this paper, we present femtosecond laser-based direct-write approaches for the fabrication of (1) waveguide in-coupling gratings and (2) volume Bragg reflection gratings via permanent refractive index changes within the lithium niobate substrate. In combination with metal surface-acoustic-wave transducers, these direct-write approaches allow for complete fabrication of a functional spatial light modulator via femtosecond laser direct writing.

  15. Dark and bright blocker soliton interaction in defocusing waveguide arrays.

    PubMed

    Smirnov, Eugene; Rüter, Christian E; Stepić, Milutin; Shandarov, Vladimir; Kip, Detlef

    2006-11-13

    We experimentally demonstrate the interaction of an optical probe beam with both bright and dark blocker solitons formed with low optical light power in a saturable defocusing waveguide array in photorefractive lithium niobate. A phase insensitive interaction of the beams is achieved by means of counterpropagating light waves. Partial and full reflection (blocking) of the probe beam on the positive or negative light-induced defect is obtained, respectively, in good agreement with numerical simulations.

  16. Amplification of ps-pulses from freely triggerable gain-switched laser diodes at 1062 nm and second harmonic generation in periodically poled lithium niobate

    NASA Astrophysics Data System (ADS)

    Schönau, Thomas; Riecke, Sina M.; Lauritsen, Kristian; Erdmann, Rainer

    2011-03-01

    We present a compact frequency-doubled laser source with fundamental wavelength operation at 1062 nm. A freely triggerable seed diode laser delivers sub-100 ps pulses in the picojoule range at variable repetition rates up to 80 MHz. After amplification in a Ytterbium-doped fiber amplifier, the average power exceeds 380mW at 40 MHz, which corresponds to 9.5 nJ pulses and about 75W of peak power. The output beam is then focussed into periodically poled lithium niobate for second harmonic generation (SHG). In this way, green picosecond pulses with an energy of up to 2 nJ at 40MHz are generated. The pulse energy and pulse shape of the second harmonic pulses are systematically studied for various repetition rates, allowing conclusions on the amplifier performance under different operating conditions.

  17. Electro-optic spectral tuning in a fan-out double-prism domain periodically poled lithium niobate intracavity optical parametric oscillator.

    PubMed

    Chang, W K; Chung, H P; Lin, Y Y; Chen, Y H

    2016-08-15

    We report on the design and experimental demonstration of an electro-optically tunable, pulsed intracavity optical parametric oscillator (IOPO) based on a unique fan-out double-prism domain periodically poled lithium niobate (DPD PPLN) in a diode-pumped Nd:YVO4 laser. The PPLN device combines the functionalities of fan-out and ramped duty-cycle domain structured nonlinear crystals, working simultaneously as a continuous grating-period quasi-phase-matched optical parametric downconverter and an electro-optic beam deflector/Q switch in the laser system. When driving the fan-out DPD PPLN with a voltage pulse train and varying the DC offset of the pulse train, a pulsed IOPO was realized with its signal and idler being electro-optically tunable over the 1880 and 2453 nm bands at spectral tuning rates of 13.5 (measured) and 25.8 (calculated) nm/(kV/mm), respectively.

  18. Optical isolator based on the electro-optic effect in periodically poled lithium niobate with the addition of a half domain.

    PubMed

    Shi, Lei; Tian, Linghao; Chen, Xianfeng

    2012-12-20

    We propose an optical isolator based on the electro-optic (EO) effect of periodically poled lithium niobate (PPLN). When the EO effect occurs in PPLN under a TE field, each domain serves as a half-wave plate under the quasi-phase-matching condition, and PPLN shows optical activity similar to quartz. The introduction of an additional half-domain to the normal PPLN changes the incident azimuth angle of the reflected light. As a result, the reflected light does not return to the original polarization state. Thus, the optical rotation accumulates and optical isolation occurs. The isolator can be employed for all linearly polarized light and has the advantage of being used in a weak-light system with low driving voltage and high isolation contrast.

  19. The effect of an optical pump on the absorption coefficient of magnesium-doped near-stoichiometric lithium niobate in terahertz range

    NASA Astrophysics Data System (ADS)

    Zuo, Zhi-Gao; Ling, Fu-Ri; Ma, De-Cai; Wu, Liang; Liu, Jin-Song; Yao, Jian-Quan

    2013-10-01

    The absorption coefficient of magnesium-doped near-stoichiometric lithium niobate crystal is measured by terahertz time-domain spectroscopy in a frequency range of 0.2 THz-0.9 THz at room temperature. The absorption coefficient is modulated by external optical pump fields. Experimental results show that the absorption coefficient of near-SLN:Mg crystal is approximately in a range of 22 cm-1-35 cm-1 in a frequency range of 0.2 THz-0.9 THz and tunable up to nearly 15%. Further theoretical analysis reveals that the variation of absorption coefficient is related to the number of light-induced carriers, domain reversal process, and OH- absorption in this crystal.

  20. Laser-induced-damage threshold of periodically poled lithium niobate for 1030 nm femtosecond laser pulses at 100 kHz and 75 MHz

    NASA Astrophysics Data System (ADS)

    Pipinyté, I.; Grigonis, R.; Stankevičiuté, K.; Kičas, S.; Drazdys, R.; Eckardt, R. C.; Sirutkaitis, V.

    2013-07-01

    We report laser-induced damage threshold (LIDT) measurements of periodically poled lithium niobate (PPLN) and magnesium-oxide-doped PPLN (MgO:PPLN) in the femtosecond pulse duration regime at 1030 nm with 100 kHz and 75 MHz repetition rate. PPLN and MgO:PPLN crystals with broadband Nb2O5/SiO2 AR coatings for 1.4 - 1.8 um spectral range were used. S-on-1 test for LIDT measurements were performed. S was equal to 106 and 4.56*1010 pulses for 100 kHz CPA laser system and 75 MHz oscillator, respectively. Evaluated LIDT was 20 mJ/cm2 for 290 fs pulses at 100 kHz repetition rate and 0.63 mJ/cm2 for 105 fs pulses at 76 MHz repetition rate.

  1. Continuous-wave sodium D2 resonance radiation generated in single-pass sum-frequency generation with periodically poled lithium niobate.

    PubMed

    Yue, J; She, C-Y; Williams, B P; Vance, J D; Acott, P E; Kawahara, T D

    2009-04-01

    With two cw single-mode Nd:YAG lasers at 1064 and 1319 nm and a periodically poled lithium niobate crystal, 11 mW of 2 kHz/100 ms bandwidth single-mode tunable 589 nm cw radiation has been detected using single-pass sum-frequency generation. The demonstrated conversion efficiency is approximately 3.2%[W(-1) cm(-1)]. This compact solid-state light source has been used in a solid-state-dye laser hybrid sodium fluorescence lidar transmitter to measure temperatures and winds in the upper atmosphere (80-105 km); it is being implemented into the transmitter of a mobile all-solid-state sodium temperature and wind lidar under construction.

  2. Broadband frequency-chirped terahertz-wave signal generation using periodically-poled lithium niobate for frequency-modulated continuous-wave radar application

    NASA Astrophysics Data System (ADS)

    Hamazaki, Junichi; Ogawa, Yoh; Sekine, Norihiko; Kasamatsu, Akifumi; Kanno, Atsushi; Yamamoto, Naokatsu; Hosako, Iwao

    2016-02-01

    We have proposed a method by using a nonlinear optical technique to generate frequency-modulated (FM) signals in the terahertz (THz) band with much broader bandwidth. Periodically-poled lithium niobates (PPLNs) are excited by ultrashort pulses, and linearly frequency-chirped THz pulses are obtained by changing the periodicity of the PPLN gradually. The bandwidth achieved is approximately 1 THz at a center frequency of 1.5 THz. Using this wave in a FM continuous (CW) radar system is expected to result in a range resolution of ~150 μm. This FM-THz signal generation technique will thus be useful in or future civil safety applications requiring high-resolution ranging or imaging.

  3. Investigation of defect structure of impurity-doped lithium niobate by combining thermodynamic constraints with lattice constant variations

    SciTech Connect

    Koyama, Chihiro; Nozawa, Jun Fujiwara, Kozo; Uda, Satoshi; Maeda, Kensaku

    2015-01-07

    The defect structures of impurity-doped congruent lithium niobates (c-LN) were determined for impurities with various valences, including divalent, trivalent, and tetravalent impurities, in a concentration range where antisite niobium (Nb{sub Li}) exists. On the basis of the “Li site vacancy model,” six kinds of defect structures in impurity-doped c-LN are possible. Using thermodynamic constraints, these can be narrowed down to two kinds. The first structure is that in which impurities, vacancies and Nb exist as defects in the Li site and no defects exist in the Nb site (structure A), described as ([Li{sub Li}] {sub 1-5x-jy}[Nb{sub Li}]{sub x}[M{sub Li}]{sub y}[V{sub Li}]{sub 4x+(j-1)y})[Nb{sub Nb}][O{sub O}] {sub 3} (V: vacancy, M: impurity, j: valence of impurity, x, y: compositional variable (≠0), Li/Nb = congruent ratio). ([Li{sub Li}{sup ×}] {sub 1-5x-2y}[Nb{sub Li}{sup ••••}]{sub x}[M{sub Li}{sup •}]{sub y}[V{sub Li}{sup ′}]{sub 4x+y})[Nb{sub Nb}{sup ×}][O{sub O}{sup ×}] {sub 3} is an example by the Kröger-Vink notation for divalent M. In the second structure, vacancies and Nb exist as defects in the Li site and impurities exist as defects in the Nb site (structure B), described as ([Li{sub Li}] {sub 1-5x-(j-5)y}[Nb{sub Li}]{sub x}[V{sub Li}]{sub 4x+(j-5)y})([Nb{sub Nb}] {sub 1-y}[M{sub Nb}]{sub y})[O{sub O}] {sub 3}. ([Li{sub Li}{sup ×}] {sub 1-5x+y}[Nb{sub Li}{sup ••••}]{sub x}[V{sub Li}{sup ′}]{sub 4x-y})([Nb{sub Nb}{sup ×}] {sub 1-y}[M{sub Nb}{sup ′}]{sub y})[O{sub O}{sup ×}] {sub 3} is an example for tetravalent M. Since the relationship between impurity concentration and lattice constants for structures A and B differs, the defect structures can be differentiated by analyzing lattice constant variations as a function of impurity concentration. The results show that the defect structure of divalent and trivalent impurity-doped c-LN is structure A and that of tetravalent impurity-doped c-LN is

  4. Generation of Counterpropagating Path-Entangled Photon Pairs in a Single Periodic Waveguide

    NASA Astrophysics Data System (ADS)

    Saravi, Sina; Pertsch, Thomas; Setzpfandt, Frank

    2017-05-01

    We propose the use of nonlinear periodic waveguides for direct and fully integrated generation of counterpropagating photon pairs by spontaneous parametric down-conversion. Using the unique properties of Bloch modes in such periodic structures, we furthermore show that two counterpropagating phase-matching conditions can be fulfilled simultaneously, allowing for the generation of path-entangled Bell states in a single periodic waveguide. To demonstrate the feasibility of our proposal, we design a photonic crystal slab waveguide made of lithium niobate and numerically demonstrate Bell-state generation.

  5. Non linear effects in LiNbO3 Waveguides

    NASA Astrophysics Data System (ADS)

    Micheli, M. D.; Papuchon, M.

    1985-09-01

    Waveguides and waveguide resonators are very useful devices for nonlinear interactions. Indeed, they permit having a very high density of energy and quite long interaction lengths, and lead to devices with high conversion efficiency for low pumping power [1, 2] . In the visible and the near infrared, the most convenient material for nonlinear effects is Lithium Niobate in which we are able to realize good waveguides by Titanium Indiffusion (TI). In this paper we shall discuss the new waveguide fabrication process that we developped in Nice : Titanium Indiffusion Proton Exchange (TIPE), and we show by the example of Second Harmonic Generation (SHG) the new possibilities of these waveguides which enables us to design very interesting parametric devices.

  6. Continuous-wave quasi-phase-matched generation of 60thinspthinspmW at 465thinspthinspnm by single-pass frequency doubling of a laser diode in backswitch-poled lithium niobate

    SciTech Connect

    Batchko, R.G.; Fejer, M.M.; Byer, R.L.; Woll, D.; Wallenstein, R.; Shur, V.Y.; Erman, L.

    1999-09-01

    We report continuous-wave single-pass second-harmonic generation (SHG) in 4-{mu}m -period 0.5-mm-thick backswitch-poled lithium niobate. Pump sources at 920{endash}930thinspthinspnm include both Ti:sapphire and diode-oscillator{endash}amplifier lasers. SHG of a Ti:sapphire laser at 6.1{percent}/W efficiency, producing 61thinspthinspmW of power at 460thinspthinspnm, is demonstrated in 50-mm-long periodically poled lithium niobate samples with a nonlinear coefficient d{sub eff}{approx}9 pm/V , and 60thinspthinspmW at 465thinspthinspnm and 2.8{percent}/W efficiency is obtained by SHG of a laser-diode source. {copyright} {ital 1999} {ital Optical Society of America}

  7. Structural, morphological and electrical studies of lithium ion irradiated sodium potassium niobate single crystal grown by flux method

    NASA Astrophysics Data System (ADS)

    Saravanan, R.; Rajesh, D.; Rajasekaran, S. V.; Perumal, R.; Chitra, M.; Jayavel, R.

    2013-02-01

    Single crystals of sodium potassium niobate (K0.5Na0.5)NbO3 (KNN) were grown by flux method and crystals were irradiated with 45 MeV Li ions to modify the electrical properties. Energy of the irradiated heavy ion was lower than the threshold energy to produce columnar defect and only clusters of defect was observed. The surface morphology of the irradiated single crystals was studied using scanning electron microscope (SEM) and atomic force microscope (AFM). The results show that the surface roughness value was found to increase with increasing fluence.

  8. Structural, morphological and electrical studies of lithium ion irradiated sodium potassium niobate single crystal grown by flux method

    SciTech Connect

    Saravanan, R.; Rajesh, D.; Rajasekaran, S. V.; Perumal, R.; Chitra, M.; Jayavel, R.

    2013-02-05

    Single crystals of sodium potassium niobate (K{sub 0.5}Na{sub 0.5})NbO{sub 3} (KNN) were grown by flux method and crystals were irradiated with 45 MeV Li ions to modify the electrical properties. Energy of the irradiated heavy ion was lower than the threshold energy to produce columnar defect and only clusters of defect was observed. The surface morphology of the irradiated single crystals was studied using scanning electron microscope (SEM) and atomic force microscope (AFM). The results show that the surface roughness value was found to increase with increasing fluence.

  9. Formation of self-organized domain structures with charged domain walls in lithium niobate with surface layer modified by proton exchange

    NASA Astrophysics Data System (ADS)

    Shur, V. Ya.; Akhmatkhanov, A. R.; Chuvakova, M. A.; Dolbilov, M. A.; Zelenovskiy, P. S.; Lobov, A. I.

    2017-03-01

    We have studied the self-organized dendrite domain structures appeared as a result of polarization reversal in the uniform field in lithium niobate single crystals with the artificial surface layer created by proton exchange. We have revealed the self-organized sub-micron scale dendrite domain patterns consisting of domain stripes oriented along the X crystallographic directions separated by arrays of dashed residual domains at the surface by scanning probe microscopy. Raman confocal microscopy allowed visualizing the quasi-regular dendrite domain structures with similar geometry in the vicinity of both polar surfaces. The depth of the structure was about 20 μm for Z+ polar surface and 70 μm for Z- one. According to the proposed mechanism, the dendrite structure formation at the surface was related to the ineffective screening of the residual depolarization field. The computer simulation of the structure formation based on the cellular automata model with probabilistic switching rule proved the eligibility of the proposed scheme, the simulated dendrite domain patterns at various depths being similar to the experimental ones.

  10. Sub-nanosecond periodically poled lithium niobate optical parametric generator and amplifier pumped by an actively Q-switched diode-pumped Nd:YAG microlaser

    NASA Astrophysics Data System (ADS)

    Liu, L.; Wang, H. Y.; Ning, Y.; Shen, C.; Si, L.; Yang, Y.; Bao, Q. L.; Ren, G.

    2017-05-01

    A sub-nanosecond seeded optical parametric generator (OPG) based on magnesium oxide-doped periodically poled lithium niobate (MgO:PPLN) crystal is presented. Pumped by an actively Q-switched diode-pumped 1 kHz, 1064 nm, Nd:YAG microlaser and seeded with a low power distributed feedback (DFB) diode continuous-wave (CW) laser, the OPG generated an output energy of 41.4 µJ and 681 ps pulse duration for the signal at 1652.4 nm, achieving a quantum conversion efficiency of 61.2% and a slope efficiency of 41.8%. Signal tuning was achieved from 1651.0 to 1652.4 nm by tuning the seed-laser current. The FWHM of the signal spectrum was approximately from 35 nm to 0.5 nm by injection seed laser. The SHG doubled the frequency of OPG signal to produce a output energy of 12 µJ with the energy conversion efficiency of 29.0% and tunanble wavelength near 826 nm.

  11. Design of an optical 4-bit binary to BCD converter using electro-optic effect of lithium niobate based Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh

    2017-07-01

    Binary to Binary coded decimal (BCD) converter is a basic building block for BCD processing. The last few decades have witnessed exponential rise in applications of binary coded data processing in the field of optical computing thus there is an eventual increase in demand of acceptable hardware platform for the same. Keeping this as an approach a novel design exploiting the preeminent feature of Mach-Zehnder Interferometer (MZI) is presented in this paper. Here, an optical 4-bit binary to binary coded decimal (BCD) converter utilizing the electro-optic effect of lithium niobate based MZI has been demonstrated. It exhibits the property of switching the optical signal from one port to the other, when a certain appropriate voltage is applied to its electrodes. The projected scheme is implemented using the combinations of cascaded electro-optic (EO) switches. Theoretical description along with mathematical formulation of the device is provided and the operation is analyzed through finite difference-Beam propagation method (FD-BPM). The fabrication techniques to develop the device are also discussed.

  12. Raman Study of Photorefractive Nonlinearity in TITANIUM:LITHIUM Niobate and of Silicon Crystallite Formation in Silicon Dioxide

    NASA Astrophysics Data System (ADS)

    Ramabadran, Uma B.

    1990-01-01

    Photorefractive non-linearities in electro-optic crystals have been widely investigated in a variety of materials including LiNbO_3. This phenomenon is also observed in the Ti:LiNbO_3 channel waveguide which is typically a few microns in thickness and width and therefore experiences high power densities which gives rise to this effect. The non-linearity is observed in the unidirectional energy transfer from one waveguide mode to an orthogonal one causing a polarization rotation. A threshold value of power necessary to initiate the polarization rotation can be obtained and used to calculate a value of beta_{15 }, an asymmetric component of the photovoltaic tensor. Elastic scattered light is collected over a distance of the propagating guided wave and the scattering loss as a function of distance is calculated. The Raman spectrometer was used in a novel way to measure inelastic scattered light from the waveguide surface as a function of propagatory distance and this data used to calculate the loss coefficient. In this way, the contributions due to surface inhomogeneities were neglected and a value of the loss characteristic of the guiding medium alone was obtained. The measurements were carried out in the channel waveguides of Ti:LiNbO _3 described above and in planar waveguides of Si^+/N^+ implanted in SiO_2 thermally grown on silicon substrates. In the latter case, the Raman macrochamber was used with a large collection lens to obtain sufficient signal. Different annealing cycles were performed to optimize the waveguide quality. This thesis also reports the investigation of diffusion characteristics of silicon when samples of high -dose silicon ion-implanted in crystalline quartz were subjected to rapid thermal or laser annealing. Characterization techniques included differential interference microscopy, Rutherford backscattering spectroscopy and Raman microprobe spectroscopy. The data obtained indicated that rapid thermal annealing results in the formation of

  13. waveguides

    NASA Astrophysics Data System (ADS)

    Bauters, Jared F.; Adleman, James R.; Heck, Martijn J. R.; Bowers, John E.

    2014-08-01

    Planar waveguides with ultra-low propagation loss are necessary for integrating optoelectronic systems that require long optical time delay or narrowband optical filters. In this paper, we review an ultra-low loss planar waveguide platform that uses thin (<150 nm) Si3N4 cores and thick (>8 μm) SiO2 cladding layers. In particular, we discuss the performance of arrayed waveguide gratings (AWGs) fabricated with the platform. We propose the use of a practical design method that takes the statistical nature of worst-case crosstalk into account. We also demonstrate the measurement of amplitude and phase error distributions in an AWG using an optical backscatter reflectometer. We show that the waveguides have phase errors small enough to achieve AWG crosstalk below -30 dB, while crosstalk below -40 dB should also be possible with optimization of the component design.

  14. Complex investigations of structural and optical homogeneities of low-photorefractivity lithium niobate crystals by the conoscopy and photoinduced and Raman light scattering methods

    NASA Astrophysics Data System (ADS)

    Sidorov, N. V.; Pikoul, O. Yu.; Kruk, A. A.; Teplyakova, N. A.; Yanichev, A. A.; Palatnikov, M. N.

    2015-02-01

    Using photoinduced light scattering, conoscopy, and Raman spectroscopy methods, we have studied stoichiometric lithium niobate crystals and congruent crystals that were doped with Mg(0.078, 0.89 mas %), Zn(0.03, 0.52, 0.62), Cu(0.015), B(0.12), Gd(0.51), Y(0.46), Gd(0.23):Mg(0.75), Mg(0.86):Fe(0.0036), Ta(1.13):Mg(0.011), and Y(0.24):Mg(0.63) cations. It has been found that, depending on the kind of the pattern of photoinduced light scattering, investigated specimens can be divided into three groups. We have shown that the asymmetry of the indicatrix of photoinduced light scattering of LiNbO3 crystals is caused by birefringence of exciting laser radiation as it propagates perpendicularly to the polar axis of the crystal, whereas the asymmetry of the Raman spectrum arises due to the occurrence of spontaneous polarization, the vector of which is directed along the polar axis, and by birefringence. The pattern of the photoinduced light scattering depends on the difference of the refractive indices Δ n = n o - n e of the ordinary ( n o ) and extraordinary ( n e ) rays and their energies E. If En o {ie259-1} En e , the proportion of the photoinduced light scattering has the shape of a three-layer round spot. For equal energies, the pattern has the shape of a symmetric figure-eight. At En o < En e , the figure-eight is asymmetric. In this case, its large "lobe" is directed in the positive direction of the polar axis of the crystal.

  15. Design of a hybrid As₂S₃-Ti:LiNbO₃ optical waveguide for phase-matched difference frequency generation at mid-infrared.

    PubMed

    Wang, Xin; Madsen, Christi K

    2014-11-03

    Based on arsenic tri-sulfide films on titanium-diffused lithium niobate, we designed a hybrid optical waveguide for efficient mid-infrared emission by phase-matched difference frequency generation (DFG). The hybrid waveguide structure possesses a low-index magnesium fluoride buffer layer sandwiched between two high-index As(2)S(3) slabs, so that pump and signal waves are tightly confined by titanium-diffused waveguide while the DFG output idler wave at mid-infrared is confined by the whole hybrid waveguide structure. On a 1 mm-long hybrid waveguide pumped at 50 mW powers, a normalized power conversion efficiency of 20.52%W(-1)cm(-2) was theoretically predicted, which is the highest record for mid-infrared DFG waveguides based on lithium niobate crystal, to the best of our knowledge. Using a tunable near-infrared pump laser at 1.38-1.47 µm or a tunable signal laser at 1.95-2.15 µm, a broad mid-infrared tuning range from 4.0 µm to 4.9 µm can be achieved. Such hybrid optical waveguides are feasible for mid-infrared emission with mW powers and sub-nanometer linewidths.

  16. Two-wave mixing of ion-implanted photorefractive waveguides in near-stoichiometric Fe:LiNbO 3 crystals

    NASA Astrophysics Data System (ADS)

    Peng, Baogang; Chen, Feng; Tan, Yang; Kip, Detlef

    2011-04-01

    We report on the two-wave mixing of light in photorefractive waveguides in H ion-implanted Fe-doped near-stoichiometric lithium niobate crystals. For pump light of 632.8 nm wavelength a gain coefficient as high as 15 cm -1 is found. A response time of the order of a few seconds is achieved for micro-watt input powers.

  17. Molten salt synthesis of alkali niobate powders

    SciTech Connect

    Arendt, R.H.; Rosolowski, J.H.

    1980-11-18

    A mixture of niobium pentoxide, an oxide of an alkali selected from the group consisting of sodium, potassium, lithium and mixtures thereof, and an alkali chloride salt solvent is heated to melt the chloride salt solvent in which the niobium oxide and alkali oxide dissolve and react precipitating the alkali niobate.

  18. Optical waveguides in Er:LiNbO3 fabricated by different techniques - A comparison

    NASA Astrophysics Data System (ADS)

    Cajzl, Jakub; Nekvindová, Pavla; Macková, Anna; Malinský, Petr; Oswald, Jiří; Staněk, Stanislav; Vytykáčová, Soňa; Špirková, Jarmila

    2016-03-01

    We report on the comparison of three techniques used for the fabrication of optical waveguides in erbium doped lithium niobate crystal substrates (Er:LiNbO3). The techniques include ion in-diffusion from a titanium metal layer, annealed proton exchange (APE), and He+ ion implantation. The main focus of the work was placed on the investigation of the influence of the used optical waveguides fabrication techniques on the structural and luminescence properties of Er:LiNbO3 substrates. The results have shown that none of the used optical-waveguide-fabrication techniques significantly affect the position of erbium in the host crystal structure. It turned out, however, that the fabrication process affected luminescence intensities of the characteristic luminescence bands of erbium ions - the most significant decrease in the luminescence intensity was observed in the Ti-indiffused waveguides.

  19. Polarization splitter based on a three waveguide directional coupler using quantum mechanical analogies

    NASA Astrophysics Data System (ADS)

    Aashna, Pragati; Thyagarajan, K.

    2017-06-01

    We propose a novel waveguide polarization splitter based on the optical analogue of two-photon Rabi oscillations and stimulated Raman adiabatic passage in a three waveguide directional coupler. Both these processes are borrowed from three level quantum mechanical atomic systems, in which an intermediate level is used to transfer the population from one state to another without any population occupation in the intermediate level. To show the practical feasibility of the device, simulations have been carried out on waveguides in lithium niobate and we show that two orthogonal polarizations can be separated at the output using the proposed three waveguide structures. We also show that the proposed structure is robust against changes in phase mismatch parameters, as well as wavelength of operation.

  20. 2.4-watts second-harmonic generation in ppZnO:LN ridge waveguide for lithium laser cooling.

    PubMed

    Kretzschmar, Norman; Eismann, Ulrich; Sievers, Franz; Chevy, Frédéric; Salomon, Christophe

    2017-06-26

    We present a simple all-solid-state laser source emitting 2.4 W of single-frequency light at 671 nm for laser cooling of lithium atoms. It is based on a diode-pumped solid-state laser, which is frequency doubled in a ppZnO:LN ridge waveguide with an internal doubling efficiency of 54%. We develop a simple theory for the thermal effects we observed at elevated fundamental powers, and compare the setup to a more efficient but more complex one with an external resonant frequency doubling cavity providing 5.2 W at 671 nm.

  1. 4.0 μm, high repetition rate periodically poled magnesium-oxide-doped lithium niobate mid-infrared optical parametric oscillator pumped by steep leading edge pulsed fiber laser.

    PubMed

    Wang, Lu; Liu, Qiang; Ji, Encai; Chen, Hailong; Gong, Mali

    2014-10-10

    A high repetition rate optical parametric oscillator (OPO) generating an idler laser with a wavelength as long as 4.0 μm at 200 and 400 kHz was demonstrated in this paper. The OPO was pumped by a master oscillator power amplifier structure fiber laser with excellent characteristics. The pump pulse from the fiber laser had a steep leading edge, which was theoretically proved to improve the OPO's performance, compared with the Gaussian pump pulse. A homemade periodically poled magnesium-oxide-doped lithium niobate crystal with a grating period of 29 μm was employed in our experiment. By optimizing the resonator, 2.75 and 1.67 W idler lasers were finally achieved at repetition rates as high as 200 and 400 kHz, respectively, with a wavelength as long as 4.0 μm. The conversion efficiencies were 12.03% and 7.31%, respectively.

  2. Analysis of the refractive index change of optical waveguide in LiNbO3 using a femtosecond laser

    NASA Astrophysics Data System (ADS)

    Yang, Shi-han; Zhang, Liang; Lin, Xue-song; Feng, Jie; Zhou, Zi-gang; Chen, Jang-jun

    2014-11-01

    We used a commercially available 75 MHz regeneratively amplified laser system emitting 50 femtosecond pulses of energies up to 3nJ at a wavelength of 800 nm. All waveguides were fabricated by focussing the femotsecond pulse train polarised parallel to the x-axis to a distance of approximately 125 μm below the sample surface using a 0.65 NA, ×40 microscope objective and translating the sample along the y axis. To find the optimum waveguide fabrication parameters the translation speed was varied from 2 to 100 μm/s. We introduces a method of measuring the refractive index of optical waveguide in ten micrometer. Useing CCD to measure the two-dimensional near-field light intensity distribution of the output cross-section of the waveguide, by measuring the two-dimensional near-field light intensity distribution of the output cross-section of the waveguide can be calculated the two-dimensional distribution of refractive index of waveguides. The context detailedly gives measurement results about femtosecond laser inducing the near-field intensity of lithium niobate optical waveguide cross-section and calculations of refractive index of optical waveguide. The results show that the refractive index of waveguides showed a large central, gradually reduce and the change of refractive index in the range of 0.001. This method is of great significance to measure the optical waveguide refractive index distribution.

  3. Optical characterization of femtosecond laser induced active channel waveguides in lithium fluoride crystals

    NASA Astrophysics Data System (ADS)

    Chiamenti, I.; Bonfigli, F.; Gomes, A. S. L.; Michelotti, F.; Montereali, R. M.; Kalinowski, H. J.

    2014-01-01

    We successfully realized broad-band light-emitting color center waveguides buried in LiF crystals by using femtosecond laser pulses. The characterization of the waveguides was performed by optical microscopy, photoluminescence spectra, loss measurements and near-field profiling. The experimental results show that the direct-writing fabrication process induces low-index contrast active channel waveguides: their wavelength-dependent refractive index changes, estimated from 10-3 to 10-4 depending on the writing conditions, allow supporting few modes at visible and near-infrared wavelengths.

  4. Optical characterization of femtosecond laser induced active channel waveguides in lithium fluoride crystals

    SciTech Connect

    Chiamenti, I.; Kalinowski, H. J.; Bonfigli, F.; Montereali, R. M.; Gomes, A. S. L.; Michelotti, F.

    2014-01-14

    We successfully realized broad-band light-emitting color center waveguides buried in LiF crystals by using femtosecond laser pulses. The characterization of the waveguides was performed by optical microscopy, photoluminescence spectra, loss measurements and near-field profiling. The experimental results show that the direct-writing fabrication process induces low-index contrast active channel waveguides: their wavelength-dependent refractive index changes, estimated from 10{sup −3} to 10{sup −4} depending on the writing conditions, allow supporting few modes at visible and near-infrared wavelengths.

  5. Volume integrated phase modulator based on funnel waveguides for reconfigurable miniaturized optical circuits.

    PubMed

    Parravicini, J; Martínez Lorente, R; Di Mei, F; Pierangeli, D; Agranat, A J; DelRe, E

    2015-04-01

    We demonstrate the integration of a miniaturized 30(x)  μm×30(y)  μm×2.7(z)  mm electro-optic phase modulator operating in the near-IR (λ=980  nm) based on the electro-activation of a funnel waveguide inside a paraelectric sample of photorefractive potassium lithium tantalate niobate. The modulator forms a basic tassel in the realization of miniaturized reconfigurable optical circuits embedded in a single solid-state three-dimensional chip.

  6. Strip-loaded slot waveguide: a step beyond integrated photonics limits (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Roussey, Matthieu; Ahmadi, Leila; Pélisset, Ségolène; Häyrinen, Markus; Bera, Arijit; Kontturi, Ville; Laukkanen, Janne; Vartiainen, Ismo; Honkanen, Seppo; Svirko, Yuri P.; Kuittinen, Markku

    2017-02-01

    We propose a novel waveguide type based on the concept of strip-loaded waveguide. A strip-loaded waveguide is composed of a thin-film slab waveguide allowing a vertical confinement of the electromagnetic field. A lower refractive index strip provides the lateral confinement by inducing a slight modification of the effective index in the slab. By using such a generic device we will demonstrate how the limits of integrated photonics can be extended, especially, in terms of propagation losses while adding complex structure on the waveguide. Since light sees only a slight variation of effective index, and not an abrupt change of material, propagation losses of the device are fully determined by the film rather than by the structuration. Different micro- and nano-structures will be presented through simulation and experimental results. We will focus especially on the study of Y-junctions, ring resonators, interferometers, and Bragg gratings. Another advantage of strip-loaded waveguides is the simplicity of fabrication. In order to fabricate the devices we employed nano-imprinting of polymer, a fabrication technique suitable for mass production. The low refractive index of the polymer allows a large panel of materials for the slab waveguide, e.g., silicon, titanium dioxide, and lithium niobate. This diversity in the choice of the materials gives to the platform the potential to operate on a wide wavelength range from UV to IR, for multiple applications in telecommunications, sensing and bio-sensing, and medical devices.

  7. Design of the waveguide for microwave heating of solid lithium ceramic blankets

    SciTech Connect

    Kustom, R.L.; Fendley, P.; Tidona, J.

    1985-01-01

    A description is given of the design of a dielectric-loaded waveguide for thermohydraulic testing of solid ceramic tritium breeder material in a non-nuclear environment. The dielectric-loaded waveguide provides uniform heating over module surfaces that would face a fusion reactor plasma and simulates the exponential power decay characteristic of the neutron flux over the high power region of the blankets. A 200-MHz design suitable for modules with cross section of up to 20 x 40 cm is presented.

  8. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2011-01-01

    In 2010, lithium consumption in the United States was estimated to have been about 1 kt (1,100 st) of contained lithium, a 23-percent decrease from 2009. The United States was estimated to be the fourth largest consumer of lithium. It remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. Only one company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic resources. In 2010, world lithium consumption was estimated to have been about 21 kt (22,000 st) of lithium contained in minerals and compounds, a 12-percent increase from 2009.

  9. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2010-01-01

    In 2009, lithium consumption in the United States was estimated to have been about 1.2 kt (1,300 st) of contained lithium, a 40-percent decrease from 2008. The United States was estimated to be the fourth largest consumer of lithium, and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. Only one company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic resources. In 2009, world lithium consumption was estimated to have been about 18.7 kt (20,600 st) of lithium contained in minerals and compounds.

  10. Lithium

    USGS Publications Warehouse

    Jaskula, B.W.

    2012-01-01

    In 2011, world lithium consumption was estimated to have been about 25 kt (25,000 st) of lithium contained in minerals and compounds, a 10-percent increase from 2010. U.S. consumption was estimated to have been about 2 kt (2,200 st) of contained lithium, a 100-percent increase from 2010. The United States was estimated to be the fourth-ranked consumer of lithium and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. One company, Chemetall Foote Corp. (a subsidiary of Chemetall GmbH of Germany), produced lithium compounds from domestic brine resources near Silver Peak, NV.

  11. Cascaded Second-Order Nonlinearities in Waveguides.

    NASA Astrophysics Data System (ADS)

    Sundheimer, Michael Lee

    The cascaded second-order nonlinearity arising from the second-harmonic generation process in noncentrosymmetric media is a novel approach to achieving the nonlinear phase shifts required for all-optical signal processing. The research presented in this dissertation demonstrated and measured the cascaded second-order nonlinearity for the first time in viable integrated optical waveguide formats. Cascaded self-phase modulation was measured in potassium titanyl phosphate (KTiOPO_4 or KTP) segmented quasi-phasematched waveguides at wavelengths near 855 nm and in the optical fiber telecommunications window near 1.585 μm using picosecond and femtosecond pulses, respectively. Spectral modulation and broadening were observed on the output fundamental spectrum and compared to predictions from pulsed second -harmonic generation theory under conditions of group-velocity mismatch (temporal walk-off) and group-velocity dispersion. Peak cascaded phase shifts of the fundamental of approximately pi at 855 nm were inferred with 690 W of peak guided power. Peak cascaded phase shifts of approximately pi/2 were inferred at 1.585 μm with 760 W of peak power in the guide. Direct interferometric measurements of the magnitude and sign of the cascaded nonlinear phase shift of the fundamental were performed in temperature-tuned lithium niobate (LiNbO _3) channel waveguides at 1.32 mum. The cascaded phase shift was shown to change sign upon passing through the phasematching condition, as required by theory. Peak cascaded phase shifts of +0.53 pi and -0.13 pi were measured for 86 W peak power in these waveguides. A non-uniform temperature profile along the waveguide led to a non-uniform wavevector-mismatch along the guide, resulting in an enhanced positive phase shift and an increased temperature bandwidth for the phase shift. The phase shifts achieved in this research are large enough to be suitable for some all-optical signal processing functions.

  12. Lithium

    USGS Publications Warehouse

    Ober, J.A.

    2006-01-01

    In 2005, lithium consumption in the United States was at 2.5 kt of contained lithium, nearly 32% more than the estimate for 2004. World consumption was 14.1 kt of lithium contained in minerals and compounds in 2003. Exports from the US increased slightly compared with 2004. Due to strong demand for lithium compounds in 2005, both lithium carbonate plants in Chile were operating at or near capacity.

  13. High resolution TE&TM near infrared compact spectrometer based on waveguide grating structures

    NASA Astrophysics Data System (ADS)

    Martin, G.; Thomas, F.; Heidmann, S.; de Mengin, M.; Courjal, N.; Ulliac, G.; Morand, A.; Benech, P.; Kern, P.; Le Coarer, E...

    2015-05-01

    Integrated optics spectrometers can be essentially classified into two main families: based on Fourier transform or dispersed modes. In the first case, an interferogram generated inside an optical waveguide is sampled using nanodetectors, these scatter light into the detector that is in contact with the waveguide. A dedicated FFT processing is needed in order to recover the spectrum with high resolution but limited spectral range. Another way is to extract the optical signal confined in a waveguide using a surface grating and directly obtain the spectrum by means of a relay optics that generates the spectrum on the Fourier plane of the lens, where the detector is placed. Following this second approach, we present a high-resolution compact dispersive spectrometer (δλ =1.5nm at λ=1050nm) based on guided optics technology. The propagating signal is dispersed out of a waveguide thanks to a surface grating that lays along it. Focused Ion Beam technique is used to etch nano-grooves that act as individual scattering centers and constitute the surface grating along the waveguide. The waveguide is realized using X-cut, Ypropagating Lithium Niobate substrate, where the effective index for TE and TM guided modes is different. This results in a strong angular separation of TE and TM diffracted modes, allowing simultaneous detection of spectra for both polarizations. A simple relay optics, with limited optical aberrations, reimages the diffracted signal on the focal plane array, leading to a robust, easy to align instrument.

  14. Annealing effect on planar waveguides in LiNbO 3 produced by oxygen ion implantation

    NASA Astrophysics Data System (ADS)

    Liu, Xiu-Hong; Huang, Qing; Zhao, Jin-Hua; Liu, Peng; Wang, Xue-Lin; Du, Ji-Fu; Huang, Ning-Kang

    2011-01-01

    We reported on planar waveguides in stoichiometric lithium niobate fabricated by 4.5 MeV oxygen ion implantation with a dose of 6 × 10 14 ions/cm 2 at room temperature. After ion implantation, these samples were annealed at 240 °C, 260 °C, and 300 °C for 30 min. We investigated annealing effect on the guiding modes and near-field images in the waveguides by prism-coupling method and end-face coupling method respectively. We found that for the extraordinary refractive index a positive alternation occurred in the near-surface region while a negative alternation happened at the end of ion track. Moreover, we measured the transmission spectra for the pure sample and implanted samples before and after annealed at different temperatures, and we observed an absorption peak at ˜480 nm (2.6 eV) in all of these SLN samples.

  15. Experimental study of high sensitivity infrared spectrometer with waveguide-based up-conversion detector(1).

    PubMed

    Ma, Lijun; Slattery, Oliver; Tang, Xiao

    2009-08-03

    We have developed an up-conversion spectrometer for signals at single photon levels near the infrared region based on a tunable up-conversion detector that uses a periodically poled lithium niobate waveguide as the conversion medium. We also experimentally studied its characteristics including sensitivity, dark count rate, spectral scan speed, signal transfer function of the waveguide, and polarization sensitivity. The overall single photon detection efficiency of the up-conversion spectrometer is about 32%. With its ultra high sensitivity the spectrometer can measure spectra for signals at a level as low as -126 dBm. We have demonstrated the spectrometers high sensitivity by measuring the spectrum of a greatly attenuated multimode emission from a laser diode at the 1310 nm band.

  16. Heuristic modelling of laser written mid-infrared LiNbO3 stressed-cladding waveguides.

    PubMed

    Nguyen, Huu-Dat; Ródenas, Airán; Vázquez de Aldana, Javier R; Martínez, Javier; Chen, Feng; Aguiló, Magdalena; Pujol, Maria Cinta; Díaz, Francesc

    2016-04-04

    Mid-infrared lithium niobate cladding waveguides have great potential in low-loss on-chip non-linear optical instruments such as mid-infrared spectrometers and frequency converters, but their three-dimensional femtosecond-laser fabrication is currently not well understood due to the complex interplay between achievable depressed index values and the stress-optic refractive index changes arising as a function of both laser fabrication parameters, and cladding arrangement. Moreover, both the stress-field anisotropy and the asymmetric shape of low-index tracks yield highly birefringent waveguides not useful for most applications where controlling and manipulating the polarization state of a light beam is crucial. To achieve true high performance devices a fundamental understanding on how these waveguides behave and how they can be ultimately optimized is required. In this work we employ a heuristic modelling approach based on the use of standard optical characterization data along with standard computational numerical methods to obtain a satisfactory approximate solution to the problem of designing realistic laser-written circuit building-blocks, such as straight waveguides, bends and evanescent splitters. We infer basic waveguide design parameters such as the complex index of refraction of laser-written tracks at 3.68 µm mid-infrared wavelengths, as well as the cross-sectional stress-optic index maps, obtaining an overall waveguide simulation that closely matches the measured mid-infrared waveguide properties in terms of anisotropy, mode field distributions and propagation losses. We then explore experimentally feasible waveguide designs in the search of a single-mode low-loss behaviour for both ordinary and extraordinary polarizations. We evaluate the overall losses of s-bend components unveiling the expected radiation bend losses of this type of waveguides, and finally showcase a prototype design of a low-loss evanescent splitter. Developing a realistic waveguide

  17. Photorefractive effect in iron-doped lithium niobate crystals induced by femtosecond pulses of 1.5 {mu}m wavelength

    SciTech Connect

    Beyer, O.; Breunig, I.; Kalkum, F.; Buse, K.

    2006-01-30

    Illumination of iron-doped lithium crystals (LiNbO{sub 3}:Fe) with femtosecond pulses of 1.5 {mu}m wavelength results in large refractive index changes {delta}n in the order of 10{sup -3}. The sign of the refractive index changes depends on the polarization of the recording light. The results can be very useful for fabrication of tailored holographic components for telecommunication.

  18. Lithium

    USGS Publications Warehouse

    Ober, J.

    1998-01-01

    The lithium industry can be divided into two sectors: ore concentrate producers and chemical producers. Ore concentrate producers mine lithium minerals. They beneficiate the ores to produce material for use in ceramics and glass manufacturing.

  19. Waveguide Harmonic Generator for the SIM

    NASA Technical Reports Server (NTRS)

    Chang, Daniel; Poberezhskiy, Ilya; Mulder, Jerry

    2008-01-01

    A second-harmonic generator (SHG) serves as the source of the visible laser beam in an onboard calibration scheme for NASA's planned Space Interferometry Mission (SIM), which requires an infrared laser beam and a visible laser beam coherent with the infrared laser beam. The SHG includes quasi-phase-matched waveguides made of MgO-doped, periodically poled lithium niobate, pigtailed with polarization- maintaining optical fibers. Frequency doubling by use of such waveguides affords the required combination of coherence and sufficient conversion efficiency for the intended application. The spatial period of the poling is designed to obtain quasi-phase- matching at a nominal middle excitation wavelength of 1,319.28 nm. The SHG is designed to operate at a warm bias (ambient temperature between 20 and 25 C) that would be maintained in its cooler environment by use of electric heaters; the heater power would be adjusted to regulate the temperature precisely and thereby maintain the required precision of the spatial period. At the state of development at the time of this reporting, the SHG had been packaged and subjected to most of its planned space-qualification tests.

  20. Features of APE waveguides in different Er:LiNbO 3 and (Er + Yb):LiNbO 3 cuts: electrooptical coefficient r33

    NASA Astrophysics Data System (ADS)

    Nekvindová, Pavla; Červená, Jarmila; Čapek, Pavel; Macková, Anna; Peřina, Vratislav; Schröfel, Josef; Špirková, Jarmila

    2003-12-01

    Our contribution represents a systematic study of optical layers fabricated by the annealed proton exchange (APE) method in various cuts ( X, Y, Z) of lithium niobate that was doped in bulk with erbium (500 ppm) and mixture of erbium and ytterbium in weight portion 1:9 (1000 ppm). Rutherford backscattering spectrometry (RBS), elastic recoil detection analysis (ERDA) and neutron depth profiling (NDP) methods have been used for monitoring a composition of fabricated optical layers, i.e. changes of the concentration of the rare earths (RE), hydrogen and lithium. We have used mode spectroscopy and a Mach-Zehnder interferometer to monitor the relevant properties, i.e. changes in the effective refractive index and the electrooptical coefficient r33. The obtained results show that during the APE process, there is no loss of the rare earths from the substrate and that during the treatment of the as-exchanged samples the hydrogen concentration increases while the lithium concentration decreases. Waveguiding properties and composition of the RE doped waveguides were not substantially changed compared with those fabricated in pristine lithium niobate. The presence of the doping ions decreases the r33, however, a carefully designed APE technology can increase the r33 almost to the value of the pristine LiNbO 3. A correlation between the uniform distribution of lithium and high values of the electrooptic coefficient r33 was found. According to our results the proton exchange not necessarily lowers the efficiency of the 1.5 μm emission and certainly does not lower the concentration of the RE.

  1. Recent results on photonic devices made by laser writing: 3D 3T near IR waveguides, mid-IR spectrometers and electro-optic beam combiners

    NASA Astrophysics Data System (ADS)

    Martin, G.; Vázquez de Aldana, J. R.; Rodenas, A.; d'Amico, C.; Stoian, R.

    2016-07-01

    Direct laser writing is a powerful technique for the development of astrophotonic devices, namely by allowing 3D structuring of waveguides and structures. One of the main interests is the possibility to avoid in-plane crossings of waveguides that can induce losses and crosstalk in future multi-telescope beam combiners. We will present our results in 3D three telescope beam combiners in the near infrared, that allow for phase closure studies. Besides, laser writing can be used to inscribe a grating over long distances along the waveguide direction. This can be used as an on-chip diffraction grating or as a way to sample a stationary wave that can be obtained in the waveguide. Thus, integrated optics spectrometers based on the SWIFTS concept (stationary wave integrated Fourier transform spectrometer) have been realized and characterized in the near and mid infrared using commercial chalcogenide glasses. Finally, we will also present our results on laser writing on electro-optic materials, that allow to obtain waveguides and beam combiners that can be phase-modulated using electrodes. We have focused our work on two well-known materials: Lithium Niobate, that allows for TM waveguides and has a high electro-optical coefficient, and BGO, that has a lower coefficient, but presents the advantage of being isotropic, guiding both TE and TM polarizations identically.

  2. Phase engineered wavelength conversion of ultra-short optical pulses in TI:PPLN waveguides

    NASA Astrophysics Data System (ADS)

    Babazadeh, Amin; Nouroozi, Rahman; Sohler, Wolfgang

    2016-02-01

    A phase engineered all-optical wavelength converter for ultra-short pulses (down to 140 fs) in a Ti-diffused, periodically poled lithium niobate (Ti:PPLN) waveguide is proposed. The phase engineering, due to the phase conjugation between signal and idler (converted signal) pulses which takes place in the cascaded second harmonic generation and difference frequency generation (cSHG/DFG) based wavelength conversion, already leads to shorter idler pulses. The proposed device consists of an unpoled (passive) waveguide section beside of the PPLN waveguide section in order to compensate pulse broadening and phase distortion of the idler pulses induced by the wavelength conversion (in the PPLN section). For example numerical analysis shows that a 140 fs input signal pulse is only broadened by 1.6% in a device with a combination of 20 mm and 6 mm long periodically poled and unpoled waveguide sections. Thus, cSHG/DFG based wavelength converters of a bandwidth of several Tbits/s can be designed.

  3. Fabrication of LiNbO3-As2S3 waveguides for beam steering applications

    NASA Astrophysics Data System (ADS)

    Macik, Dwayne D.; Madsen, Christi K.

    2016-09-01

    A hybrid annealed proton exchange (APE) waveguide with a vertically integrated arsenic trisulfide (As2S3) waveguide on a lithium niobate (LiNbO3) substrate is used to create an optical phased array (OPA) that allows for the non-mechanical steering of 1550 nm light on an integrated optic platform. The high electro-optic coefficient of the x-cut y-propagating LiNbO3 (r33 = 30.8 pm/V) is utilized by electrode structures fabricated on the LiNbO3 substrate to create a low-power, lowloss beam steering with high-speed bandwidths, capable of 10 GHz and larger as demonstrated by commercial LiNbO3 modulators. The As2S3 waveguide is introduced because of its high refractive index, which leads to a highly confined optical mode. Design and fabrication are presented for a large full width steering angle of 34°, representing an order of magnitude improvement over low-confinement, diffused LiNbO3 waveguides and two orders of magnitude improvement over other reported LiNbO3 OPAs.

  4. Confocal Raman imaging of optical waveguides in LiNbO3 fabricated by ultrafast high-repetition rate laser-writing.

    PubMed

    Ródenas, Airán; Nejadmalayeri, Amir H; Jaque, Daniel; Herman, Peter

    2008-09-01

    We report on the confocal Raman characterization of the micro-structural lattice changes induced during the high-repetition rate ultrafast laser writing of buried optical waveguides in lithium niobate (LiNbO(3)) crystals. While the laser beam focal volume is characterized by a significant lattice expansion together with a high defect concentration, the adjacent waveguide zone is largely free of defects, undergoing only slight rearrangement of the oxygen octahedron in the LiNbO(3) lattice. The close proximity of these two zones has been found responsible for the propagation losses of the guided light. Subjacent laser-induced periodic micro-structures have been also observed inside the laser focal volume, and identified with a strong periodic distribution of lattice defects.

  5. Nonlinear optical response in single alkaline niobate nanowires.

    PubMed

    Dutto, F; Raillon, C; Schenk, K; Radenovic, A

    2011-06-08

    We have synthesized and characterized three types of perovskite alkaline niobate nanowires: NaNbO(3), KNbO(3), and LiNbO(3) (XNbO(3)). All three types of nanowires exhibit strong nonlinear response. Confocal imaging has been employed to quantitatively compare the efficiency of synthesized nanowires to generate second harmonic signal and to show that LiNbO(3) nanowires exhibit the strongest nonlinear response. We also investigated the polarization response of the second harmonic generation (SHG) signal in all three types of alkaline nanowires for the two geometries tractable by our optical trapping setup. The SHG signal is highly influenced by the nanowire crystallinity and experimental geometry. We also demonstrate for the first time wave-guiding of SHG signal in all three types of alkaline niobate nanowires. By carefully examining nonlinear properties of (XNbO(3)) nanowires we suggest which type of wires are best suited for the given application.

  6. Highly efficient heralded single-photon source for telecom wavelengths based on a PPLN waveguide.

    PubMed

    Bock, Matthias; Lenhard, Andreas; Chunnilall, Christopher; Becher, Christoph

    2016-10-17

    We present the realization of a highly efficient photon pair source based on spontaneous parametric downconversion (SPDC) in a periodically poled lithium niobate (PPLN) ridge waveguide. The source is suitable for long distance quantum communication applications as the photon pairs are located at the centers of the telecommunication O- and C- band at 1312 nm and 1557 nm. The high efficiency is confirmed by a conversion efficiency of 4 × 10-6 - which is to our knowledge among the highest conversion efficiencies reported so far - and a heralding efficiency of 64.1 ± 2.1%. The heralded single-photon properties are confirmed by the measurement of the photon statistics with a Click/No-Click method as well as the heralded g(2)-function. A minimum value for g(2)(0) of 0.001 ± 0.0003 indicating clear antibunching has been observed.

  7. Ndp and Rbs Study of Lithium Niobate

    NASA Astrophysics Data System (ADS)

    Mackova, A.; Perina, V.; Hnatowicz, V.; Vacik, J.; Cervena, J.; Groetzschel, R.; Nekvindova, P.; Spirkova, J.

    2003-06-01

    Nuclear analytical methods are very important in materials research. We provide in Nuclear Physics Institute (NPI) several nuclear analytical methods, i.e. Rutherford Backscattering Spectrometry (RBS), Elastic Recoil Detection Analysis (ERDA), and Neutron Depth Profiling (NDP). The methods mentioned above were applied in the study of nonlinear optical materials, such as LiNbO3, to explain the mechanism of ion exchange in the near-surface layers of the substrates and to determine the profile of laser active Er ions. Depth profiles of Li in LiNbO3 were measured by NDP. We are able to evaluate the hydrogen depth profiles from ERDA measurement and Er depth profile from RBS measurement. We present the results of the complex study of LiNbO3 treated by ion exchange and low temperature diffusion of laser active ions by NDP, RBS and ERDA.

  8. Observation of photorefractive simultons in lithium niobate.

    PubMed

    Fazio, Eugenio; Belardini, Alessandro; Alonzo, Massimo; Centini, Marco; Chauvet, Mathieu; Devaux, Fabrice; Scalora, Michael

    2010-04-12

    Spatial and temporal locking of fundamental and second harmonic pulses was realized by means of photorefractive nonlinearity and highly mismatched harmonic generation. Due to the presence of both phase-locked and unlocked second harmonic pulses, a twin simultonic state was observed. Simultonic filamentation occurring at high pumping rates allowed us to determine a relation between the simulton's waist and its intensity.

  9. Effects in a lithium tantalate waveguide structure exposed to radiation from a flash x-ray source

    SciTech Connect

    West, R.H.; Dowling, S. )

    1994-06-01

    The effects of radiation from a flash X ray machine on an optical waveguide formed in LiTaO[sub 3] are described. Transient induced losses are accompanied by effects of an electric field generated by the radiation. At low temperatures, radiation-induced photorefraction dominates the response.

  10. Testing a novel μ-Raman method to retrieve refractive index and density field from femtosecond laser-written optical waveguides

    NASA Astrophysics Data System (ADS)

    Tejerina, M. R.; Torchia, G. A.

    2016-11-01

    In this work, we analysed the refractive index field and other local material properties of femtosecond laser-written waveguides properly combining a novel and direct Raman strategy, waveguides coupling and instrumented nano-indentation. At first, we measured a 2D Raman map within the cross section of femtosecond laser-written waveguides. Then, the Raman Phonon Deformation Constants of lithium niobate were employed to retrieve the strain and density variation from the A1(TO) phonon shifts in the analysed region. We test the results obtained with different combinations of phonons by computing the numerical guided modes and comparing them with those experimentally measured. As a relevant finding, we found that the combination of the A1(TO)1 and A1(TO)4 phonon shifting is the most proper one to compute strain, density and refractive index variation, almost in this kind of waveguide. Finally, a linear path across waveguides cross section was explored with instrumented nano-indentation and the expected variation of local density was detected through a softening of the elastic module observed in the region directly modified by the ultra-fast laser.

  11. Lithium tetraborate transducer cuts

    NASA Astrophysics Data System (ADS)

    Kosinski, John; Ballato, Arthur; Lukaszek, Theodore

    1990-03-01

    Lithium tetraborate is a tetragonal material of considerable promise for frequency control and signal processing applications. It exhibits piezoelectric coupling values that fall between those of lithium niobate and quartz, but possesses orientations for which the temperature coefficient of frequency and delay time is zero for bulk and surface acoustic waves. In this report, we discuss the properties of two doubly rotated bulk wave resonator orientations having both first- and second-order temperature coefficients equal to zero. These are suitable for shear and compressional wave transducers in applications where very low temperature sensitivity is required simultaneously with moderately strong piezocoupling coefficients.

  12. Lithium tetraborate transducers

    NASA Astrophysics Data System (ADS)

    Ballato, Arthur; Kosinski, John A.; Lukaszek, Ted J.

    1991-01-01

    Lithium tetraborate is a tetragonal material of considerable promise for frequency control and signal processing applications. It exhibits piezoelectric coupling values that fall between those of lithium niobate and quartz, but possesses orientations for which the temperature coefficient of frequency and delay time is zero for bulk and surface acoustic waves. The properties of two doubly rotated bulk wave resonator orientations having first- and second-order temperature coefficients equal to zero are discussed. These are suitable for shear and compressional wave transducers in applications where very low temperature sensitivity is required simultaneously with moderately strong piezocoupling coefficients.

  13. Pyrochlore-type tin niobate.

    PubMed

    Cruz, L P; Savariault, J M; Rocha, J

    2001-09-01

    A single crystal of Sn(1.59)Nb(1.84)O(6.35) was grown at 1273 K from a mixture of sodium niobate and tin(II) chloride. The structure is of pyrochlore type A(2)B(2)O(7). The tin is partially oxidized to tin(IV) and competes with niobium for the occupation of site B. The stereoactivity of the Sn(2+) lone pair induces displacement of tin towards the O atoms of the tunnel.

  14. Photonic Crystal Fabrication in Lithium Nobate via Pattern Transfer Through Wet and Dry Etched Chromium Mask

    DTIC Science & Technology

    2012-10-02

    literature.8 After the chromium mask is removed, the sample can be cleaned by a simple acetone and isopropanol wash, provided all ZEP residue is...Photonic crystal fabrication in lithium niobate via pattern transfer through wet and dry etched chromium mask Ozgur Yavuzcetin, Herman P. Novikov...OCT 2012 2. REPORT TYPE 3. DATES COVERED 00-00-2012 to 00-00-2012 4. TITLE AND SUBTITLE Photonic crystal fabrication in lithium niobate via

  15. Niobate-based octahedral molecular sieves

    DOEpatents

    Nenoff, Tina M.; Nyman, May D.

    2006-10-17

    Niobate-based octahedral molecular sieves having significant activity for multivalent cations and a method for synthesizing such sieves are disclosed. The sieves have a net negatively charged octahedral framework, comprising niobium, oxygen, and octahedrally coordinated lower valence transition metals. The framework can be charge balanced by the occluded alkali cation from the synthesis method. The alkali cation can be exchanged for other contaminant metal ions. The ion-exchanged niobate-based octahedral molecular sieve can be backexchanged in acidic solutions to yield a solution concentrated in the contaminant metal. Alternatively, the ion-exchanged niobate-based octahedral molecular sieve can be thermally converted to a durable perovskite phase waste form.

  16. Niobate-based octahedral molecular sieves

    DOEpatents

    Nenoff, Tina M.; Nyman, May D.

    2003-07-22

    Niobate-based octahedral molecular sieves having significant activity for multivalent cations and a method for synthesizing such sieves are disclosed. The sieves have a net negatively charged octahedral framework, comprising niobium, oxygen, and octahedrally coordinated lower valence transition metals. The framework can be charge balanced by the occluded alkali cation from the synthesis method. The alkali cation can be exchanged for other contaminant metal ions. The ion-exchanged niobate-based octahedral molecular sieve can be backexchanged in acidic solutions to yield a solution concentrated in the contaminant metal. Alternatively, the ion-exchanged niobate-based octahedral molecular sieve can be thermally converted to a durable perovskite phase waste form.

  17. Generation of modal- and path-entangled photons using a domain-engineered integrated optical waveguide device

    SciTech Connect

    Lugani, Jasleen; Ghosh, Sankalpa; Thyagarajan, K.

    2011-06-15

    Integrated optical devices are expected to play a promising role in the field of quantum information science and technology. In this paper we propose a scheme for the generation of nondegenerate, copolarized, modal, and path-entangled photons using a directional coupler and an asymmetric Y-coupler geometry in type-0 phase-matched domain-engineered lithium niobate (LN) waveguide. The nonlinearity in LN is tailored in such a way that quasi-phase-matching conditions for two different spontaneous parametric down-conversion processes are obeyed simultaneously, leading to a modal and path-entangled state at the output. Assuming typical values of various parameters, we show, through numerical simulations, that an almost maximally entangled state is achievable over a wide range of waveguide parameters. For the degenerate case, the proposed scheme gives a NOON state for N = 2. The generated entangled photon pairs should have potential applications in quantum information schemes and also in quantum metrology. By appropriate domain engineering and component designing, the idea can be further extended to generate hyperentangled and two-photon multipath-entangled states, which may have further applications in quantum computation protocols.

  18. Surface acoustic wave properties of proton-exchanged LiNbO3 waveguides with SiO2 film.

    PubMed

    Kao, Kuo-Sheng; Cheng, Chien-Chuan; Chung, Chung-Jen; Chen, Ying-Chung

    2005-03-01

    Surface acoustic wave (SAW) properties of proton-exchanged (PE) z-cut lithium niobate (LiNbO3) waveguides with silicon dioxide (SiO2) film layers were investigated using octanoic acid. The distribution of hydrogen measured by secondary ion mass spectrometry (SIMS) showed a step-like profile, which was assumed to be equal to the waveguide depth (d). The SiO2 film was deposited on z-cut LiNbO3 waveguide by radio frequency (rf) magnetron sputtering. We investigated the important parameters for the design of SAW devices such as phase velocity (Vp), insertion loss (IL) and temperature coefficient of frequency (TCF) by a network analyzer using thin-film aluminum interdigital transducer electrodes on the upper SiO2 film surface. The experimental results showed that the Vp of SAW decreased slightly with the increase of h/lambda, where h was the thickness of SiO2 films and lambda was the wavelength. The IL of SAW increased with increased h/lambda. The TCF of SAW calculated from the frequency change of the output of SAW delay line showed an evident decrease with the increase of h/lambda. The TCF for PE z-cut LiNbO3 was measured to be about -54.72 ppm/degreees C at h/lambda = 0.08. It revealed that the SiO2 films could compensate and improve the temperature stability as compared with the TCF of SAW on PE samples without SiO2 film.

  19. Chemically Prepared Lead Magnesium Niobate Dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-01-01

    A chemical solution powder synthesis technique has been developed that produces fine uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions.

  20. Metallic waveguide mirrors in polymer film waveguides

    NASA Astrophysics Data System (ADS)

    Wolff, S.; Giehl, A. R.; Renno, M.; Fouckhardt, H.

    2001-10-01

    A technology for the fabrication of metallic waveguide mirrors is developed. Plane and curved waveguide mirrors, the latter acting in the same way as cylindrical lenses, are realized in benzocyclobutene (BCB) film waveguides. The waveguide mirror structure is dry-etched into the BCB film waveguide. To enhance the reflectivity of the waveguide mirrors, the waveguide edge is metallized. The BCB film waveguide mirrors are characterized with respect to waveguide attenuation and mirror reflectivity. The waveguide attenuation of the processed BCB waveguide is 0.5 dB/cm. Ag-coated BCB waveguide mirrors show a reflectivity of 71%. The efficiency of total internal reflection (TIR, i.e. in the case without metallization) at the dry-etched waveguide edge is 74%. As an application of the BCB waveguide mirrors a hybrid integrated optical module for Fourier-optical transverse mode selection in broad area lasers (BAL) is proposed.

  1. Photorefractive properties of iron-doped stoichiometric lithium niobate.

    PubMed

    Furukawa, Y; Kitamura, K; Ji, Y; Montemezzani, G; Zgonik, M; Medrano, C; Günter, P

    1997-04-15

    The photorefractive properties of stoichiometric LiNbO(3) crystals with a small number of defect densities grown by the double-crucible Czochralski method are investigated and compared with the defect densities of commercially available congruent Fe-doped LiNbO(3) crystals. Two-wave-mixing experiments show that novel stoichiometric crystals exhibit larger photorefractive gain and considerably faster response times than congruent ones. The results indicate that the nonstoichiometry defect control of photorefractive crystals is of key importance for the improvement of their properties.

  2. Optical nonlinearities of small polarons in lithium niobate

    NASA Astrophysics Data System (ADS)

    Imlau, Mirco; Badorreck, Holger; Merschjann, Christoph

    2015-12-01

    An overview of optical nonlinearities of small bound polarons is given, which can occur in the congruently melting composition of LiNbO3. Such polarons decisively influence the linear and nonlinear optical performance of this material that is important for the field of optics and photonics. On the basis of an elementary phenomenological approach, the localization of carriers in a periodic lattice with intrinsic defects is introduced. It is applied to describe the binding energies of four electron and hole small polarons in LiNbO3: small free NbNb4 + polarons, small bound NbLi4 + polarons, small bound NbLi4 +:NbNb4 + bipolarons, and small bound O- hole polarons. For the understanding of their linear interaction with light, an optically induced transfer between nearest-neighboring polaronic sites is assumed. It reveals spectrally well separated optical absorption features in the visible and near-infrared spectral range, their small polaron peak energies and lineshapes. Nonlinear interaction of light is assigned to the optical formation of short-lived small polarons as a result of carrier excitation by means of band-to-band transitions. It is accompanied by the appearance of a transient absorption being spectrally constituted by the individual fingerprints of the small polarons involved. The relaxation dynamics of the transients is thermally activated and characterized phenomenologically by a stretched exponential behavior, according to incoherent 3D small polaron hopping between regular and defect sites of the crystal lattice. It is shown that the analysis of the dynamics is a useful tool for revealing the recombination processes between small polarons of different charge. Nonlinear interaction of small polarons with light furthermore results in changes of the index of refraction. Besides its causal relation to the transients via Kramers-Kronig relation, pronounced index changes may occur due to optically generated electric fields modulating the index of refraction via the linear electro-optic effect, also. Based on a microscopic picture and by considering the local structural environment of bound polarons, the appearance of photovoltaic currents is explained straightforwardly as a result of the optically induced carrier transfer. Both transient absorption and index changes are spatially confined to the intensity profile of the interacting light allowing for the recording of efficient mixed absorption and phase volume holograms. By means of holographic spectroscopy, these small-polaron based optical nonlinearities are verified either without or with the action of the linear electro-optic effect; their prominent features are highlighted by appropriate experimental studies wherin the ultrafast response on the picosecond time scale is the most recognized one. Based on these findings, the consequences for applications of LiNbO3 in the field of nonlinear optics and photonics are presented. Besides visionary examples like real-time, 3D holographic displays, the impact of optical nonlinearities of small polarons for present applications are discussed with frequency conversion and respective limiting effects, such as green-induced infrared absorption and optical damage, as important example.

  3. Red beam generation based on aperiodically poled lithium niobate

    NASA Astrophysics Data System (ADS)

    Figen, Ziya Gürkan; Akın, Onur

    2014-04-01

    We propose a novel device with a simple architecture for high-power red beam generation. The device is an optical parametric generator based on an aperiodically poled LiNbO3 grating in which both the optical parametric amplification and sum frequency generation processes are simultaneously phase matched. The pump is a quasi-continuous-wave laser operating at 1064 nm. Aperiodic gratings which enable simultaneous phase matching of the two processes were designed using a method that gives the flexibility to adjust the relative strength of these two processes. A model that takes the diffraction of the beams into account was developed to characterize the red beam generation performance of the device depending on the parameters: the relative strength of these processes, the length of the crystal, the average pump power, and the pump beam waist radius. If one uses the 2-D Fourier transform in the solution of the coupled-mode equations, the computation power required for performing such a characterization on a personal computer is prohibitively large. Owing to the circular symmetry of the system, we employ the Hankel transform to overcome this bottleneck.

  4. LOADED WAVEGUIDES

    DOEpatents

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  5. Lead magnesium niobate actuator for micropositioning

    DOEpatents

    Swift, Charles D.; Bergum, John W.

    1994-01-01

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated.

  6. Lead magnesium niobate actuator for micropositioning

    DOEpatents

    Swift, C.D.; Bergum, J.W.

    1994-10-25

    An improved lead magnesium niobate actuator is disclosed comprising a cylindrical lead magnesium niobate crystal stack mounted in a cylindrical casing wherein a bias means, such as one or more belleville washers, is located between one end of the crystal stack and a partially closed end of the casing; and adjustment means are provided which bear against the opposite end of the crystal stack, whereby an adjustable compressive force is constantly applied against the crystal stack, whether the crystal stack is actuated in an extended position, or is in an unactuated contracted position. In a preferred embodiment, cooling ports are provided for the circulation of coolant in the actuator to cool the crystal stack, and provision is made for removal and replacement of the crystal stack without disconnecting the actuator from the external device being actuated. 3 figs.

  7. Chemically prepared lead magnesium niobate dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-11-01

    A chemical solution powder synthesis technique has been developed that produces first, uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions. Chem-prep PMN dielectrics with peak dielectric constants greater than 22,000 and polarizations in excess of 29 {micro}C/cm{sup 2} were obtained for 1,100 C firing treatments. Substantial decreases in dielectric constant and polarization were measured for chemically prepared PMN ceramics fired at lower temperatures, consistent with previous work on mixed oxide materials.

  8. Improved process for making thin-film sodium niobate capacitors

    NASA Technical Reports Server (NTRS)

    Micka, E. Z.

    1968-01-01

    Sodium niobate, formed by high vacuum, flash, and reactive evaporations, has a high dielectric constant and is used as a thin film dielectric in microelectronic capacitors. High purity films are formed from relatively inexpensive, pure starting materials. Crystalline sodium niobate films can be formed on amorphous or crystalline materials.

  9. Ceramic Waveguides

    NASA Astrophysics Data System (ADS)

    Yeh, C.; Shimabukuro, F.; Stanton, P.; Jamnejad, V.; Imbriale, W.; Manshadi, F.

    2000-01-01

    This article is an expanded version of an original article published in Nature (April 6, 2000) entitled, "Millimeter/Submillimeter Wave Communications via Ceramic Ribbon." Finding a very low-loss waveguide in the millimeter-/submillimeter-wave range has been a problem of considerable interest for many years. Researching the fundamentals, we have found a new way to design a waveguide structure that is capable of providing an attenuation coefficient of less than 10 dB/km for the guided dominant mode. This structure is a ceramic (Coors' 998 alumina) ribbon with an aspect ratio of 10:1. This attenuation figure is more than one hundred times smaller than that for a typical ceramic or other dielectric circular-rod waveguide. It appears that the dominant transverse magnetic (TM)-like mode is capable of "gliding" along the surface of the ribbon with exceedingly low attenuation and with a power pattern having a dip in the core of the ribbon guide. This feature makes the ceramic ribbon a true "surface" waveguide structure wherein the wave is guided along, adhering to a large surface with only a small fraction of the power being carried within the core region of the structure. Here, through theoretical analysis as well as experimental measurements, the existence of this low-loss ceramic ribbon structure is proven. Practical considerations, such as an efficient launcher as well as supports for a long open ribbon structure, also have been tested experimentally. The availability of such a low-loss waveguide may now pave the way for new development in this millimeter-/submillimeter-wave range.

  10. Anisotropic thermal expansion of strontium barium niobate

    NASA Astrophysics Data System (ADS)

    Qadri, Syed B.; Bellotti, Jeffrey A.; Garzarella, Anthony; Wu, Dong Ho

    2005-06-01

    Strontium barium niobate is a tungsten-bronze ferroelectric crystal having a tetragonal unit cell. Low-temperature x-ray diffraction studies were performed on a single crystal of Sr0.75Ba0.25Nb2O6 to determine the thermal expansivity along the a- and c-axes. Negative thermal expansion was observed along the c direction while a positive thermal expansion was measured along the a axis. The anisotropic thermal expansion behavior is explained as arising due to the geometry of the crystal structure.

  11. Preparation of multicomponent niobate piezoelectric ceramic

    SciTech Connect

    Aboltinya, I.V.; Vinogradova, I.S.; Freidenfel'd, E.Z.

    1988-03-01

    Using x-ray phase analysis and differential thermal analysis to study the process by which solid solutions of complex niobates are formed, the authors have determined that this process is characterized by overlapping and parallel reactions in which intermediate compounds are formed. On the basis of samples of the Li/sub 2/O-Na/sub 2/O-Nb/sub 2/O/sub 5/ system doped with the oxides MgO, CaO, SrO, BaO, or TiO/sub 2/ they obtained piezoelectric ceramic materials with low values of the dielectric constant and comparatively high piezoelectric properties.

  12. Electrocaloric properties of potassium tantalate niobate crystals

    NASA Astrophysics Data System (ADS)

    Maiwa, Hiroshi

    2016-10-01

    The electrocaloric properties of potassium tantalate niobate (KTN) crystals were investigated by indirect estimation and direct measurement of temperature-electric field (T-E) hysteresis loops. The measured T-E loops showed a similar shape to strain-electric field (s-E) loops. The adiabatic temperature change ΔT due to the electrocaloric effect was estimated from the polarization change of this sample to be 0.49 K under a field of 20 kV/cm. The measured temperature change ΔT in these samples upon the release of the electric field from 20 kV/cm to zero was 0.42 K. The temperature dependences of the electromechanical and electrocaloric properties were measured. The maximum performance appeared at approximately the phase transition temperature of KTN crystal and the properties were relatively moderate-temperature-dependent.

  13. Short-Pitch Periodically Poled Lithium-Niobate And Lithium Tantalate

    DTIC Science & Technology

    2007-11-02

    noise ( Barkhausen pulses) which can be related with jump-like motion of the domain walls [24,25]. 18 Figure 15 Switching currents measured for...the only source of the steps. It is clear that the observed jump-like wall motion should lead to switching current noise ( Barkhausen jumps) (Fig. 25

  14. Compact waveguide circular polarizer

    SciTech Connect

    Tantawi, Sami G.

    2016-08-16

    A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.

  15. Gamma-ray waveguides

    SciTech Connect

    Tournear, D. M.; Hoffbauer, M. A.; Akhadov, E. A.; Chen, A. T.; Pendleton, S. J.; Williamson, T. L.; Cha, K. C.; Epstein, R. I.

    2008-04-14

    We have developed an approach for gamma-ray optics using layered structures acting as planar waveguides. Experiments demonstrating channeling of 122 keV gamma rays in two prototype waveguides validate the feasibility of this technology. Gamma-ray waveguides allow one to control the direction of radiation up to a few MeV. The waveguides are conceptually similar to polycapillary optics, but can function at higher gamma-ray energies. Optics comprised of these waveguides will be able to collect radiation from small solid angles or concentrate radiation into small area detectors. Gamma-ray waveguides may find applications in medical imaging and treatment, astrophysics, and homeland security.

  16. Waveguide cooling system

    NASA Technical Reports Server (NTRS)

    Chen, B. C. J.; Hartop, R. W. (Inventor)

    1981-01-01

    An improved system is described for cooling high power waveguides by the use of cooling ducts extending along the waveguide, which minimizes hot spots at the flanges where waveguide sections are connected together. The cooling duct extends along substantially the full length of the waveguide section, and each flange at the end of the section has a through hole with an inner end connected to the duct and an opposite end that can be aligned with a flange hole in another waveguide section. Earth flange is formed with a drainage groove in its face, between the through hole and the waveguide conduit to prevent leakage of cooling fluid into the waveguide. The ducts have narrowed sections immediately adjacent to the flanges to provide room for the installation of fasteners closely around the waveguide channel.

  17. Waveguide formation mechanism generated by double doping in ferroelectric crystals

    NASA Astrophysics Data System (ADS)

    Atuchin, V. V.; Ziling, C. C.; Savatinova, I.; Armenise, M. N.; Passaro, V. M. N.

    1995-12-01

    Physical mechanisms causing the refractive index increase Δn in uniaxial oxidized ferroelectric crystals subjected to double doping are discussed. The analysis shows that the index changes of the two different dopants, ΔnA and ΔnB, are additive only if the corresponding changes of the spontaneous polarization are small. Ti indiffusion and proton exchange (TIPE) waveguides in LiNbO3 are considered as an example of the case when this condition is not fulfilled. The hydrogen-lithium substitution in such waveguides leads to a strong reduction of the spontaneous polarization of the virgin crystals and the final index change Δn is not a sum of ΔnA and ΔnB. A physical model is developed to explain light waveguiding in double-doped ferroelectric structures. Experimental data obtained for TIPE waveguides confirm the model.

  18. Highly dispersive slot waveguides.

    PubMed

    Zhang, Lin; Yue, Yang; Xiao-Li, Yinying; Beausoleil, Raymond G; Willner, Alan E

    2009-04-27

    We propose a slot-waveguide with high dispersion, in which a slot waveguide is coupled to a strip waveguide. A negative dispersion of up to -181520 ps/nm/km is obtained due to a strong interaction of the slot and strip modes. A flat and large dispersion is achievable by cascading the dispersive slot-waveguides with varied waveguide thickness or width for dispersion compensation and signal processing applications. We show - 31300 ps/nm/km dispersion over 147-nm bandwidth with <1% variance.

  19. Micromachined Silicon Waveguide Circuits

    NASA Technical Reports Server (NTRS)

    McGrath, W. R.

    1995-01-01

    Rectangular waveguides are commonly used as circuit elements in remote-sensing heterodyne receivers at millimeter wavelengths. The advantages of waveguides are low loss and mechanical tunability. However, conventional machining techniques for waveguide components operating above a few hundred GHz are complicated and costly. Waveguides micromachined from silicon however would have several important advantages including low-cost; small size for very high frequency (submillimeter wave) operation; high dimensional accuracy (important for high-Q circuits); atomically smooth walls, thereby reducing rf losses; and the ability to integrate active and passive devices directly in the waveguide on thin membranes, thereby solving the traditional problem of mounting thin substrates.

  20. Offset Waveguide Transmission Measurements

    NASA Technical Reports Server (NTRS)

    Cravey, Robin

    1997-01-01

    This report describes measurements to determine transmission losses in S-band (2.60-3.95 GHz) waveguide sections due to misalignment of the sections relative to each other. The experiments were performed in support of the Hydrostar program to determine the feasibility of using deployable waveguide sections in a large space radiometer. The waveguide sections would possibly be hinged and folded for launch, then deployed in space to form long sections of waveguide. Since very low losses are required for radiometer applications, the effects of potential misalignment after deployment of the waveguide sections may be significant. These measurements were performed in the Electromagnetic Properties Measurement Laboratory in the Electromagnetics Research Branch.

  1. Lithium battery technology

    SciTech Connect

    Venkatasetty, A.V.

    1984-01-01

    This book presents papers on the use of lithium in electric batteries. Topics considered include solvents for lithium battery technology, transport properties and structure of nonaqueous electrolyte solutions, primary lithium batteries, lithium sulfur dioxide batteries, lithium oxyhalide batteries, medical batteries, ambient-temperature rechargeable lithium cells, high-temperature lithium batteries, and lithium ion-conducting solid electrolytes.

  2. Interconnect Between a Waveguide and a Dielectric Waveguide Comprising an Impedance Matched Dielectric Lens

    NASA Technical Reports Server (NTRS)

    Decrossas, Emmanuel (Inventor); Chattopadhyay, Goutam (Inventor); Chahat, Nacer (Inventor); Tang, Adrian J. (Inventor)

    2016-01-01

    A lens for interconnecting a metallic waveguide with a dielectric waveguide is provided. The lens may be coupled a metallic waveguide and a dielectric waveguide, and minimize a signal loss between the metallic waveguide and the dielectric waveguide.

  3. Waveguide disturbance detection method

    DOEpatents

    Korneev, Valeri A.; Nihei, Kurt T.; Myer, Larry R.

    2000-01-01

    A method for detection of a disturbance in a waveguide comprising transmitting a wavefield having symmetric and antisymmetric components from a horizontally and/or vertically polarized source and/or pressure source disposed symmetrically with respect to the longitudinal central axis of the waveguide at one end of the waveguide, recording the horizontal and/or vertical component or a pressure of the wavefield with a vertical array of receivers disposed at the opposite end of the waveguide, separating the wavenumber transform of the wavefield into the symmetric and antisymmetric components, integrating the symmetric and antisymmetric components over a broad frequency range, and comparing the magnitude of the symmetric components and the antisymmetric components to an expected magnitude for the symmetric components and the antisymmetric components for a waveguide of uniform thickness and properties thereby determining whether or not a disturbance is present inside the waveguide.

  4. Hydrogen, lithium, and lithium hydride production

    DOEpatents

    Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.; Powell, G. Louis; Campbell, Peggy J.

    2017-06-20

    A method is provided for extracting hydrogen from lithium hydride. The method includes (a) heating lithium hydride to form liquid-phase lithium hydride; (b) extracting hydrogen from the liquid-phase lithium hydride, leaving residual liquid-phase lithium metal; (c) hydriding the residual liquid-phase lithium metal to form refined lithium hydride; and repeating steps (a) and (b) on the refined lithium hydride.

  5. Planar waveguide optical immunosensors

    NASA Astrophysics Data System (ADS)

    Choquette, Steven J.; Locascio-Brown, Laurie E.; Durst, Richard A.

    1991-03-01

    Monoclonal antibodies were covalently bonded to the surfaces of planar waveguides to confer immunoreacth''ity. Silver-ion diffused waveguides were used to measure theophylline concentrations in a fluorescence immunoassay and silicon nitride waveguides were used to detect theophylline in an absorbance-based immunoassay. Liposomes were employed in both assays as the optically detectable label in a competitive reaction to monitor antigen-antibody complexation. Regeneration of the active antibody site will be discussed.

  6. Hydrogen, lithium, and lithium hydride production

    DOEpatents

    Brown, Sam W; Spencer, Larry S; Phillips, Michael R; Powell, G. Louis; Campbell, Peggy J

    2014-03-25

    A method of producing high purity lithium metal is provided, where gaseous-phase lithium metal is extracted from lithium hydride and condensed to form solid high purity lithium metal. The high purity lithium metal may be hydrided to provide high purity lithium hydride.

  7. Birefringent corrugated waveguide

    SciTech Connect

    Moeller, C.P.

    1989-02-15

    A corrugated waveguide having a circular bore and noncircularly symmetric corrugations, and preferably elliptical corrugations, provides birefringence for rotation of polarization in the HE{sub 11} mode. The corrugated waveguide may be fabricated by cutting circular grooves on a lathe in a cylindrical tube or rod of aluminium of a diameter suitable for the bore of the waveguide, and then cutting an approximation to ellipses for the corrugations using a cutting radius R{sub 0} from the bore axis that is greater than the bore radius, and then making two circular cuts using a radius R{sub 1} less than R{sub 0} at centers +b and {minus}b from the axis of the waveguide bore. Alternatively, stock for the mandrel may be formed with an elliptical transverse cross section, and then only the circular grooves need be cut on a lathe, leaving elliptical corrugations between the grooves. In either case, the mandrel is first electroplated and then dissolved leaving a corrugated waveguide with noncircularly symmetric waveguides. A transition waveguide is used that gradually varies from circular to elliptical corrugations to couple a circularly corrugated waveguide to an elliptically corrugated waveguide.

  8. Broad band waveguide spectrometer

    DOEpatents

    Goldman, Don S.

    1995-01-01

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  9. Electron Waveguide Devices

    NASA Astrophysics Data System (ADS)

    Eugster, Cristopher Conrad

    This thesis explores a new frontier for electronic devices: the electron waveguide regime where the confining dimensions are made comparable to the electron wavelength and scattering is removed from the channel. Motivated by the possibility of implementing an "electron directional coupler", we study this new regime of electron transport with a novel device called a dual electron waveguide device. Such a device consists of three split-gates patterned on top of an AlGaAs/GaAs modulation-doped heterostructure. Under proper bias, two one-dimensional electron waveguides can be formed in close proximity of one another. The middle -gate which is used to control the interaction between the two waveguides is only 30 nm wide. The side-gates are used to control the number of occupied subbands in the two respective waveguides. Since these gates can be independently accessed, many different electron waveguide configurations can be implemented using this novel structure. In this thesis, we study the transport and tunneling characteristics of isolated electron waveguides, leaky electron waveguides and closely spaced electron waveguides using our novel device concept. In the tunneling spectroscopy experiments of leaky electron waveguides, we have dramatically uncovered the 1D subband structure of our electron waveguides. We have also observed for the first time 1D to 1D tunneling between two closely spaced electron waveguides. The resulting pattern in the 1D to 1D tunneling regime is consistent with the energy and momentum conservation laws in the tunneling process. In this thesis, we also investigate some of the more practical issues behind electron waveguide devices. We show how only a few local scatterers in the device can degrade the ideal electron waveguide features. We also show how the increased functionality of our dual electron waveguide devices can be used to implement an efficient analog-to-digital conversion architecture. (Copies available exclusively from MIT

  10. Waveguide arrangements based on adiabatic elimination

    SciTech Connect

    Suchowski, Haim; Mrejen, Michael; Wu, Chihhui; Zhang, Xiang

    2016-09-13

    This disclosure provides systems, methods, and apparatus related to nanophotonics. In one aspect, an arrangement of waveguides includes a substrate and three waveguides. Each of the three waveguides may be a linear waveguide. A second waveguide is positioned between a first waveguide and a third waveguide. The dimensions and positions of the first, the second, and the third waveguides are specified to substantially eliminate coupling between the first waveguide and the third waveguide over a distance of about 1 millimeter to 2 millimeters along lengths of the first waveguide, the second waveguide, and the third waveguide.

  11. Birefringent corrugated waveguide

    DOEpatents

    Moeller, Charles P.

    1990-01-01

    A corrugated waveguide having a circular bore and noncircularly symmetric corrugations, and preferably elliptical corrugations, provides birefringence for rotation of polarization in the HE.sub.11 mode. The corrugated waveguide may be fabricated by cutting circular grooves on a lathe in a cylindrical tube or rod of aluminum of a diameter suitable for the bore of the waveguide, and then cutting an approximation to ellipses for the corrugations using a cutting radius R.sub.0 from the bore axis that is greater than the bore radius, and then making two circular cuts using a radius R.sub.1 less than R.sub.0 at centers +b and -b from the axis of the waveguide bore. Alternatively, stock for the mandrel may be formed with an elliptical transverse cross section, and then only the circular grooves need be cut on a lathe, leaving elliptical corrugations between the grooves. In either case, the mandrel is first electroplated and then dissolved leaving a corrugated waveguide with noncircularly symmetric corrugations. A transition waveguide is used that gradually varies from circular to elliptical corrugations to couple a circularly corrugated waveguide to an elliptically corrugated waveguide.

  12. Birefringent corrugated waveguide

    SciTech Connect

    Moeller, C.P.

    1990-03-06

    This patent describes a corrugated waveguide having a circular bore and noncircularly symmetric corrugations, and preferably elliptical corrugations which provides birefringence for rotation of polarization in the HE{sub 11} mode. The corrugated waveguide may be fabricated by cutting circular grooves on a lathe in a cylindrical tube or rod of aluminum of a diameter suitable for the bore of the waveguide, and then cutting an approximation to ellipses for the corrugations using a cutting radius R{sub 0} from the bore axis that is greater than the bore radius, and then making two circular cuts using a radius R{sub 1} less than R{sub 0} at centers + b and {minus} B from the axis of the waveguide bore. Alternatively, stock for the mandrel may be formed with an elliptical transverse cross section, and then only the circular grooves need be cut on a lathe, leaving elliptical corrugations between the grooves. In either case, the mandrel is first electroplated and then dissolved leaving a corrugated waveguide with noncircularly symmetric corrugations. A transition waveguide is used that gradually varies from circular to elliptical corrugations to couple a circularly corrugated waveguide to an elliptically corrugated waveguide.

  13. Peptide Optical waveguides.

    PubMed

    Handelman, Amir; Apter, Boris; Shostak, Tamar; Rosenman, Gil

    2017-02-01

    Small-scale optical devices, designed and fabricated onto one dielectric substrate, create integrated optical chip like their microelectronic analogues. These photonic circuits, based on diverse physical phenomena such as light-matter interaction, propagation of electromagnetic waves in a thin dielectric material, nonlinear and electro-optical effects, allow transmission, distribution, modulation, and processing of optical signals in optical communication systems, chemical and biological sensors, and more. The key component of these optical circuits providing both optical processing and photonic interconnections is light waveguides. Optical confinement and transmitting of the optical waves inside the waveguide material are possible due to the higher refractive index of the waveguides in comparison with their surroundings. In this work, we propose a novel field of bionanophotonics based on a new concept of optical waveguiding in synthetic elongated peptide nanostructures composed of ordered peptide dipole biomolecules. New technology of controllable deposition of peptide optical waveguiding structures by nanofountain pen technique is developed. Experimental studies of refractive index, optical transparency, and linear and nonlinear waveguiding in out-of-plane and in-plane diphenylalanine peptide nanotubes have been conducted. Optical waveguiding phenomena in peptide structures are simulated by the finite difference time domain method. The advantages of this new class of bio-optical waveguides are high refractive index contrast, wide spectral range of optical transparency, large optical nonlinearity, and electro-optical effect, making them promising for new applications in integrated multifunctional photonic circuits. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  14. Waveguide switch protector

    NASA Technical Reports Server (NTRS)

    Kolbly, R. B.

    1972-01-01

    Device for detecting excessive operation of electric motors used to drive waveguide switches is described. Purpose of device is to prevent burnout of electric motor in event of waveguide stoppage at some point other than extreme limits of travel. Operation of equipment, components used to sense motor performance, and schematic diagram are included.

  15. Electro-optical polycrystalline barium lanthanum titanium niobate

    SciTech Connect

    Mehrotra, A.K.

    1991-02-19

    This patent describes a transparent electro-optic article. It comprises: of a barium lanthanum titanium niobate wherein substantially all grains are of a grain size between about 2 and about 20 micron, the article has a pore volume of less than about 1 percent, and the article has a grain size of between about 2 and about 20 microns. This patent also describes a method of forming transparent electro-optical barium lanthanum titanium niobate. It comprises: providing particles of barium carbonate, lanthanum oxide, titanium oxide, and niobium oxide, calcining the particles, sintering the calcined particles at a temperature of between about 1200{degrees} C and 1300{degrees} C. and a vacuum of between about 10{sup {minus}3} and 10{sup {minus}4} torr while under pressure to form a sintered mass, cooling the sintered mass, slicing the mass to form wafers, heating the wafers in an oxidizing atmosphere.

  16. Zero-mode waveguides

    DOEpatents

    Levene, Michael J.; Korlach, Jonas; Turner, Stephen W.; Craighead, Harold G.; Webb, Watt W.

    2007-02-20

    The present invention is directed to a method and an apparatus for analysis of an analyte. The method involves providing a zero-mode waveguide which includes a cladding surrounding a core where the cladding is configured to preclude propagation of electromagnetic energy of a frequency less than a cutoff frequency longitudinally through the core of the zero-mode waveguide. The analyte is positioned in the core of the zero-mode waveguide and is then subjected, in the core of the zero-mode waveguide, to activating electromagnetic radiation of a frequency less than the cut-off frequency under conditions effective to permit analysis of the analyte in an effective observation volume which is more compact than if the analysis were carried out in the absence of the zero-mode waveguide.

  17. Nanocrystal waveguide (NOW) laser

    DOEpatents

    Simpson, John T.; Simpson, Marcus L.; Withrow, Stephen P.; White, Clark W.; Jaiswal, Supriya L.

    2005-02-08

    A solid state laser includes an optical waveguide and a laser cavity including at least one subwavelength mirror disposed in or on the optical waveguide. A plurality of photoluminescent nanocrystals are disposed in the laser cavity. The reflective subwavelength mirror can be a pair of subwavelength resonant gratings (SWG), a pair of photonic crystal structures (PC), or a distributed feedback structure. In the case of a pair of mirrors, a PC which is substantially transmissive at an operating wavelength of the laser can be disposed in the laser cavity between the subwavelength mirrors to improve the mode structure, coherence and overall efficiency of the laser. A method for forming a solid state laser includes the steps of providing an optical waveguide, creating a laser cavity in the optical waveguide by disposing at least one subwavelength mirror on or in the waveguide, and positioning a plurality of photoluminescent nanocrystals in the laser cavity.

  18. Complex Impedance Studies of Optically Excited Strontium Barium Niobate

    DTIC Science & Technology

    2007-11-02

    has a tetragonal tungsten - bronze structure. The unit cell for this structure, illustrated below in Fig. 2.1, consists of ten oxygen octahedra joined...4 Kittel, pp. 373-374. 5 P. B. Jamieson, et al, “Ferroelectric Tungsten Bronze -Type Crystal Structures. I. Barium Strontium Niobate...Oxford, 1987). 2. C. Kittel, Introduction to Solid State Physics, (Wiley, New York, 1986). 3. P. B. Jamieson, et al, “Ferroelectric Tungsten

  19. Tunable, pulsed multiline intracavity optical parametric oscillator using two-dimensional MgO: periodically poled lithium niobate-aperiodically poled lithium niobate.

    PubMed

    Chen, Y H; Chang, W K; Chung, H P; Liu, B Z; Tseng, C H; Chang, J W

    2013-09-15

    We report a tunable, pulsed multiline intracavity optical parametric oscillator (IOPO) realized in an Nd:YVO4 laser using a two-dimensionally domain engineered MgO:LiNbO3 as simultaneously an electro-optic Bragg Q switch and a multichannel optical parametric downconverter. The MgO:LiNbO3 was periodically and aperiodically poled along the crystallographic y and x axes, respectively, to simultaneously satisfy the phase-matching conditions required by the two quasi-phase-matching devices. When Q switched by 1 kHz, 300 V pulses, three signal lines at 1518, 1526, and 1534 nm were simultaneously generated, each with a peak power of ∼1  kW from the IOPO at 8.3 W diode power at 50°C. Spectral tuning of the three-line IOPO with temperature was demonstrated.

  20. Variety of neutron sensors based on scintillating glass waveguides

    NASA Astrophysics Data System (ADS)

    Bliss, Mary; Craig, Richard A.

    1995-04-01

    Pacific Northwest Laboratory (PNL) has fabricated cerium-activated lithium silicate glass scintillating fiber waveguide neutron sensors via a hot-downdraw process. These fibers typically have a transmission length (e-1 length) of greater than 2 meters. The underlying physics of, the properties of, and selected devices incorporating these fibers are described. These fibers constitute an enabling technology for a wide variety of neutron sensors.

  1. A planar lens in LiNbO3 produced by the double proton exchange method

    NASA Astrophysics Data System (ADS)

    Volkov, V. A.; Gan'shin, V. A.; Kvasha, M. Iu.; Korkishko, Iu. N.; Fedotov, S. M.

    1989-08-01

    Experiments are reported in which a waveguide lens in lithium niobate was produced by the method of double proton-lithium exchange. In this process, the formation of a Ti:LiNbO3 light waveguide is replaced by the formation of an H:LiNbO3 waveguide of identical parameters. The performance characteristics of the waveguide lenses fabricated by the method proposed here are as good as those of TIPE lenses.

  2. Lithium nephrotoxicity.

    PubMed

    Oliveira, Jobson Lopes de; Silva Júnior, Geraldo Bezerra da; Abreu, Krasnalhia Lívia Soares de; Rocha, Natália de Albuquerque; Franco, Luiz Fernando Leonavicius G; Araújo, Sônia Maria Holanda Almeida; Daher, Elizabeth de Francesco

    2010-01-01

    Lithium has been widely used in the treatment of bipolar disorder. Its renal toxicity includes impaired urinary concentrating ability and natriuresis, renal tubular acidosis, tubulointerstitial nephritis progressing to chronic kidney disease and hypercalcemia. The most common adverse effect is nephrogenic diabetes insipidus, which affects 20-40% of patients within weeks of lithium initiation. Chronic nephropathy correlates with duration of lithium therapy. Early detection of renal dysfunction should be achieved by rigorous monitoring of patients and close collaboration between psychiatrists and nephrologists. Recent experimental and clinical studies begin to clarify the mechanisms by which lithium induces changes in renal function. The aim of this study was to review the pathogenesis, clinical presentation, histopathological aspects and treatment of lithium-induced nephrotoxicity.

  3. Homogeneous thin film lens on LiNbO3

    NASA Astrophysics Data System (ADS)

    Jiang, Pisu; Laybourn, Peter J. R.; Righini, Giancarlo C.

    1991-02-01

    Problems in the fabrication of homogeneous integ ited lenses on lithium niobate were investigated. TIPE and double proton exchange waveguide . abrication methods were compared and various masking systems tested. Mode matching between a v w index single mode DMPE waveguide and a high index multi mode PE waveguide was optimized.

  4. Compound semiconductor optical waveguide switch

    DOEpatents

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  5. Acoustic Ridge Waveguide Technology

    DTIC Science & Technology

    1975-08-01

    P. E. Lagasse, I. M. Mason, and E. A. Ash, "Acoustic Surface Waveguides - Analysis and Assessment," IEEE Trans. Microwave Theory and Techniques MTT-2i»t i», 225-236 (April 1973). yt^^^^ HMMMM . . .

  6. Axially Modulated Plasma Waveguides

    SciTech Connect

    Layer, B. D.; York, A. G.; Varma, S.; Chen, Y.-H.; Milchberg, H. M.

    2009-01-22

    We demonstrate two techniques for making periodically modulated plasma waveguides-one with sharp, stable voids as short as 50 {mu}m with a period as small as 200 {mu}m, and another which modulates the waveguide diameter with a corrugation period as short as 35 {mu}m[1]. These features persist as the plasma expands for the full lifetime of the waveguide (>6 ns). The waveguides were made using the hydrodynamic shock method in a cluster jet using hydrogen, nitrogen, and argon. We demonstrate guided propagation at intensities up to 2x10{sup 17} W/cm{sup 2}, limited by our laser energy currently available. This technique is useful for quasi-phase matching to allow efficient coupling of laser energy to acceleration of relativistic electrons or generation of coherent electromagnetic radiation at selected frequencies.

  7. Microfabricated bragg waveguide

    DOEpatents

    Fleming, James G.; Lin, Shawn-Yu; Hadley, G. Ronald

    2004-10-19

    A microfabricated Bragg waveguide of semiconductor-compatible material having a hollow core and a multilayer dielectric cladding can be fabricated by integrated circuit technologies. The microfabricated Bragg waveguide can comprise a hollow channel waveguide or a hollow fiber. The Bragg fiber can be fabricated by coating a sacrificial mandrel or mold with alternating layers of high- and low-refractive-index dielectric materials and then removing the mandrel or mold to leave a hollow tube with a multilayer dielectric cladding. The Bragg channel waveguide can be fabricated by forming a trench embedded in a substrate and coating the inner wall of the trench with a multilayer dielectric cladding. The thicknesses of the alternating layers can be selected to satisfy the condition for minimum radiation loss of the guided wave.

  8. Calculate waveguide aperture susceptance

    NASA Astrophysics Data System (ADS)

    Kwon, J.-K.; Ishii, T. K.

    1982-12-01

    A method is developed for calculating aperture susceptance which makes use of the distribution of an aperture's local fields. This method can be applied to the computation of the aperture susceptance of irises, as well as the calculation of the susceptances of waveguide filters, aperture antennas, waveguide cavity coupling, waveguide junctions, and heterogeneous boundaries such as inputs to ferrite or dielectric loaded waveguides. This method assumes a local field determined by transverse components of the incident wave in the local surface of the cross section in the discontinuity plane which lies at the aperture. The aperture susceptance is calculated by the use of the local fields, the law of energy conservation, and the principles of continuity of the fields. This method requires that the thickness of the aperture structure be zero, but this does not limit the practical usefulness of this local-field method.

  9. Omnidirectional optical waveguide

    SciTech Connect

    Bora, Mihail; Bond, Tiziana C.

    2016-08-02

    In one embodiment, a system includes a scintillator material; a detector coupled to the scintillator material; and an omnidirectional waveguide coupled to the scintillator material, the omnidirectional waveguide comprising: a plurality of first layers comprising one or more materials having a refractive index in a first range; and a plurality of second layers comprising one or more materials having a refractive index in a second range, the second range being lower than the first range, a plurality of interfaces being defined between alternating ones of the first and second layers. In another embodiment, a method includes depositing alternating layers of a material having a relatively high refractive index and a material having a relatively low refractive index on a substrate to form an omnidirectional waveguide; and coupling the omnidirectional waveguide to at least one surface of a scintillator material.

  10. [Lithium nephropathy].

    PubMed

    Kaczmarczyk, Ireneusz; Sułowicz, Władysław

    2013-01-01

    Lithium salts are the first-line drug therapy in the treatment of uni- and bipolar disorder since the sixties of the twentieth century. In the mid-70s, the first information about their nephrotoxicity appeared. Lithium salts have a narrow therapeutic index. Side effects during treatment are polyuria, polydipsia and nephrogenic diabetes insipidus. Accidental intoxication can cause acute renal failure requiring renal replacement therapy while receiving long-term lithium salt can lead to the development of chronic kidney disease. The renal biopsy changes revealed a type of chronic tubulointerstitial nephropathy. The imaging studies revealed the presence of numerous symmetric microcysts. Care of the patient receiving lithium should include regular determination of serum creatinine, creatinine clearance and monitoring of urine volume. In case of deterioration of renal function reducing the dose should be considered.

  11. Lithium toxicity

    MedlinePlus

    ... Lithonate Note: Lithium is also commonly found in batteries, lubricants, high performance metal alloys, and soldering supplies. ... Kidney failure Memory problems Movement disorders Problems ... your body Psychosis (disturbed thought processes, unpredictable ...

  12. Surface modification to waveguides

    DOEpatents

    Timberlake, J.R.; Ruzic, D.N.; Moore, R.L.; Cohen, S.A.; Manos, D.M.

    1982-06-16

    A method is described for treating the interior surfaces of a waveguide to improve power transmission comprising the steps of mechanically polishing to remove surface protrusions; electropolishing to remove embedded particles; ultrasonically cleaning to remove any residue; coating the interior waveguide surfaces with an alkyd resin solution or electrophoretically depositing carbon lamp black suspended in an alkyd resin solution to form a 1..mu.. to 5..mu.. thick film; vacuum pyrolyzing the film to form a uniform adherent carbon coating.

  13. Surface modification to waveguides

    DOEpatents

    Timberlake, John R.; Ruzic, David N.; Moore, Richard L.; Cohen, Samuel A.; Manos, Dennis M.

    1983-01-01

    A method of treating the interior surfaces of a waveguide to improve power transmission comprising the steps of mechanically polishing to remove surface protrusions; electropolishing to remove embedded particles; ultrasonically cleaning to remove any residue; coating the interior waveguide surfaces with an alkyd resin solution or electrophoretically depositing carbon lamp black suspended in an alkyd resin solution to form a 1.mu. to 5.mu. thick film; vacuum pyrolyzing the film to form a uniform adherent carbon coating.

  14. On the nature of striae in strontium barium niobate

    NASA Astrophysics Data System (ADS)

    Monchamp, R. R.; Mihalik, G. B.; Franks, L. A.

    1994-08-01

    Strontium barium niobate crystals were grown by the Czochralski technique. These crystals were 15-20 mm in diameter and 25 to 75 mm long. Two types of striae, designated as coarse and fine, were characterized. The coarse striae are optically dense and are spaced by 100 to 500 microns apart; the fine striae are optically less dense and spaced 5-50 microns apart. The origins of the striae are attributed to thermal fluctuations in the melt related to the control system and to rotation of the growing crystal in non-isothermal radial gradients. Analysis of the crystals indicated that the coarse striae may contain increased concentrations of sodium.

  15. Navy Lithium Battery Safety

    DTIC Science & Technology

    2010-07-14

    lithium -sulfur dioxide (Li-SO2), lithium - thionyl chloride (Li- SOCL2), and lithium -sulfuryl chloride (Li-S02CL2...and 1980’s with active primary cells: Lithium -sulfur dioxide (Li-SO2) Lithium - thionyl chloride (Li-SOCL2) Lithium -sulfuryl chloride (Li-S0 CL ) 2 2...DISTRIBUTION A. Approved for public release; distribution unlimited. NAVY LITHIUM BATTERY SAFETY John Dow1 and Chris Batchelor2 Naval

  16. A Simple Optical Waveguide Experiment.

    ERIC Educational Resources Information Center

    Phelps, J.; Sambles, J. R.

    1989-01-01

    Describes a thin film rectangular dielectric waveguide and its laboratory use. Discusses the theory of uniaxial thin film waveguides with mathematical expressions and the laboratory procedures for a classroom experiment with diagrams. (Author/YP)

  17. A Simple Optical Waveguide Experiment.

    ERIC Educational Resources Information Center

    Phelps, J.; Sambles, J. R.

    1989-01-01

    Describes a thin film rectangular dielectric waveguide and its laboratory use. Discusses the theory of uniaxial thin film waveguides with mathematical expressions and the laboratory procedures for a classroom experiment with diagrams. (Author/YP)

  18. Phonon dynamics and inelastic neutron scattering of sodium niobate

    NASA Astrophysics Data System (ADS)

    Mishra, S. K.; Gupta, M. K.; Mittal, R.; Zbiri, M.; Rols, S.; Schober, H.; Chaplot, S. L.

    2014-05-01

    Sodium niobate (NaNbO3) exhibits an extremely complex sequence of structural phase transitions in the perovskite family and therefore provides an excellent model system for understanding the mechanism of structural phase transitions. We report temperature dependence of inelastic neutron scattering measurements of phonon densities of states in sodium niobate. The measurements are carried out in various crystallographic phases of this material at various temperatures from 300 to 1048 K. The phonon spectra exhibit peaks centered on 19, 37, 51, 70, and 105 meV. Interestingly, the peak near 70 meV shifts significantly towards lower energy with increasing temperature, while the other peaks do not exhibit any appreciable shift. The phonon spectra at 783 K show prominent change and become more diffusive as compared to those at 303 K. In order to better analyze these features, we have performed first-principles lattice dynamics calculations based on the density functional theory. The computed phonon density of states is found to be in good agreement with the experimental data. Based on our calculation we are able to assign the characteristic Raman modes in the antiferroelectric phase, which are due to the folding of the T (ω = 95 cm-1) and Δ (ω = 129 cm-1) points of the cubic Brillouin zone, to the A1g symmetry.

  19. New Metal Niobate and Silicotitanate Ion Exchangers: Development and Characterization

    SciTech Connect

    Alexandra Navrotsky; Mary Lou Balmer; Tina M. Nenoff; Yali Su

    2003-12-05

    This renewal proposal outlines our current progress and future research plans for ion exchangers: novel metal niobate and silicotitanate ion exchangers and their ultimate deployment in the DOE complex. In our original study several forms (including Cs exchanged) of the heat treated Crystalline Silicotitanates (CSTs) were fully characterized by a combination of high temperature synthesis and phase identification, low temperature synthesis and phase identification, and thermodynamics. This renewal proposal is predicated on work completed in our current EMSP program: we have shown preliminary data of a novel class of niobate-based molecular sieves (Na/Nb/M/O, M = transition metals), which show exceptionally high selectivity for divalent cations under extreme conditions (acid solutions, competing cations), in addition to novel silicotitanate phases which are also selective for divalent cations. Furthermore, these materials are easily converted by a high temperature in-situ heat treatment into a refractory ceramic waste form with low cation leachability. The new waste form is a perovskite phase, which is also a major component of Synroc, a titanate ceramic waste form used for sequestration of HLW wastes from reprocessed, spent nuclear fuel. These new niobate ion exchangers also shown orders of magnitude better selectivity for Sr2+ under acid conditions than any other material. The goal of the program is to reduce the costs associated with divalent cation waste removal and disposal, to minimize the risk of contamination to the environment during ion exchanger processing, and to provide DOE with materials for near-term lab-bench stimulant testing, and eventual deployment. The proposed work will provide information on the structure/property relationship between ion exchanger frameworks and selectivity for specific ions, allowing for the eventual ''tuning'' of framework for specific ion exchange needs. To date, DOE sites have become interested in on-site testing of these

  20. Growth and Preparation of Lead-Potassium-Niobate (PKN) Single Crystals Specimens.

    DTIC Science & Technology

    1982-12-01

    POTASSIUM- NIOBATE (PKN) SINGLE CRYSTAL S SPECIMENS ,, Texas A&M University....... ’DTIC ELECTE MAR?7 1M8 R. K. Pandey B APPROVED FOR PUBLIC RELEASE...and Subtitle) S. TYPE Of REPORT II PERIOD COVERED Final Technical Report GROWTH AND PREPARATION OF LEAD-POTASSIUM-Ap80-Sp1 NIOBATE (PKN) SINGLE...Ba, Pb, Sr, Ca, Na, K etc. and B = Nb or Ta. Lead-potassium- niobate (PKN), Pb2KNb5015, is one of the members of the family of TB- ferroelectrics

  1. Square dielectric THz waveguides.

    PubMed

    Aflakian, N; Yang, N; LaFave, T; Henderson, R M; O, K K; MacFarlane, D L

    2016-06-27

    A holey cladding dielectric waveguide with square cross section is designed, simulated, fabricated and characterized. The TOPAS waveguide is designed to be single mode across the broad frequency range of 180 GHz to 360 GHz as shown by finite-difference time domain simulation and to robustly support simultaneous TE and TM mode propagation. The square fiber geometry is realized by pulling through a heat distribution made square by appropriate furnace design. The transmitted mode profile is imaged using a vector network analyzer with a pinhole at the receiver module. Good agreement between the measured mode distribution and the calculated mode distribution is demonstrated.

  2. Actively coupled optical waveguides

    NASA Astrophysics Data System (ADS)

    Alexeeva, N. V.; Barashenkov, I. V.; Rayanov, K.; Flach, S.

    2014-01-01

    We consider light propagation through a pair of nonlinear optical waveguides with absorption, placed in a medium with power gain. The active medium boosts the in-phase component of the overlapping evanescent fields of the guides, while the nonlinearity of the guides couples it to the damped out-of-phase component creating a feedback loop. As a result, the structure exhibits stable stationary and oscillatory regimes in a wide range of gain-loss ratios. We show that the pair of actively coupled (AC) waveguides can act as a stationary or integrate-and-fire comparator sensitive to tiny differences in their input powers.

  3. Waveguide Gas Laser,

    DTIC Science & Technology

    1982-05-26

    THOSE OF THE SOURCE AND DO NOT NECESSARILY REFLECT THE POSITION TRANSLATION DIVISION OR OPINION OF THE FOREIGN TECHNOLOGY DI . FOREIGN TECHNOLOGY...z=b, R=2b). l osso EH mod/an -th dstc / • 1.5 Key: (*)6. C,,oupling Key: C.Rltosi ewe ouplingloss By utilizing the "approximate" gaussian light beam...the dis - charge tube should be adopted in order to obtain a wide oscillation belt. Abrams [4] used a waveguide CO2 laser made of BeO waveguide tube with

  4. Full spectrum millimeter-wave modulation.

    PubMed

    Macario, Julien; Yao, Peng; Shi, Shouyuan; Zablocki, Alicia; Harrity, Charles; Martin, Richard D; Schuetz, Christopher A; Prather, Dennis W

    2012-10-08

    In recent years, the development of new lithium niobate electro-optic modulator designs and material processing techniques have contributed to support the increasing need for faster optical networks by considerably extending the operational bandwidth of modulators. In an effort to provide higher bandwidths for future generations of networks, we have developed a lithium niobate electro-optic phase modulator based on a coplanar waveguide ridged structure that operates up to 300 GHz. By thinning the lithium niobate substrate down to less than 39 µm, we are able to eliminate substrate modes and observe optical sidebands over the full millimeter-wave spectrum.

  5. Photochemical Reaction Patterns on Heterostructures of ZnO on Periodically Poled Lithium Niobate.

    PubMed

    Kaur, Manpuneet; Liu, Qianlang; Crozier, Peter A; Nemanich, Robert J

    2016-10-05

    The internal electric field in LiNbO3 provides a driving force for heterogeneous photocatalytic reactions, where photoexcited holes or electrons can participate in redox reactions on positive (+c) and negative (-c) domain surfaces and at the domain boundaries. One method to characterize the surface chemical reactivity is to measure photoinduced Ag deposition by immersing the LiNbO3 in an aqueous AgNO3 solution and illuminating with above bandgap light. Reduction of Ag(+) ions leads to the formation of Ag nanoparticles at the surface, and a high density of Ag nanoparticles indicates enhanced surface photochemical reactions. In this study, an n-type semiconducting ZnO layer is deposited on periodically poled LiNbO3 (PPLN) to modulate the surface electronic properties and impact the surface redox reactions. After plasma enhanced atomic layer deposition (PEALD) of 1, 2, 4, and 10 nm ZnO thin films on PPLN substrates, the substrates were immersed in aqueous AgNO3 and illuminated with above band gap UV light. The Ag nanoparticle density increased for 1 and 2 nm ZnO/PPLN heterostructures, indicating an enhanced electron density at the ZnO/PPLN surface. However, increasing the ZnO thickness beyond 2 nm resulted in a decrease in the Ag nanoparticle density. The increase in nanoparticle density is related to the photoexcited charge density at the ZnO/PPLN interface and the presence of a weakly adsorbed Stern layer at the ZnO surface. The decrease in the nanoparticle density for thicker ZnO is attributed to photoexcited electron screening in the ZnO layer that suppresses electron flow from the LiNbO3 to ZnO surface.

  6. A coupled effect of nuclear and electronic energy loss on ion irradiation damage in lithium niobate

    DOE PAGES

    Liu, Peng; Zhang, Yanwen; Xue, Haizhou; ...

    2016-01-09

    Understanding irradiation effects induced by elastic energy loss to atomic nuclei and inelastic energy loss to electrons in a crystal, as well as the coupled effect between them, is a scientific challenge. Damage evolution in LiNbO3 irradiated by 0.9 and 21 MeV Si ions at 300 K has been studied utilizing Rutherford backscattering spectrometry in channeling mode. During the low-energy ion irradiation process, damage accumulation produced due to elastic collisions is described utilizing a disorder accumulation model. Moreover, low electronic energy loss is shown to induce observable damage that increases with ion fluence. For the same electronic energy loss, themore » velocity of the incident ion could affect the energy and spatial distribution of excited electrons, and therefore effectively modify the diameter of the ion track. Furthermore, nonlinear additive phenomenon of irradiation damage induced by high electronic energy loss in pre-damaged LiNbO3 has been observed. The result indicates that pre-existing damage induced from nuclear energy loss interacts synergistically with inelastic electronic energy loss to promote the formation of amorphous tracks and lead to rapid phase transformation, much more efficient than what is observed in pristine crystal solely induced by electronic energy loss. As a result, this synergistic effect is attributed to the fundamental mechanism that the defects produced by the elastic collisions result in a decrease in thermal conductivity, increase in the electron-phonon coupling, and further lead to higher intensity in thermal spike from intense electronic energy deposition along high-energy ion trajectory.« less

  7. A coupled effect of nuclear and electronic energy loss on ion irradiation damage in lithium niobate

    SciTech Connect

    Liu, Peng; Zhang, Yanwen; Xue, Haizhou; Jin, Ke; Crespillo, Miguel L.; Wang, Xuelin; Weber, William J.

    2016-01-09

    Understanding irradiation effects induced by elastic energy loss to atomic nuclei and inelastic energy loss to electrons in a crystal, as well as the coupled effect between them, is a scientific challenge. Damage evolution in LiNbO3 irradiated by 0.9 and 21 MeV Si ions at 300 K has been studied utilizing Rutherford backscattering spectrometry in channeling mode. During the low-energy ion irradiation process, damage accumulation produced due to elastic collisions is described utilizing a disorder accumulation model. Moreover, low electronic energy loss is shown to induce observable damage that increases with ion fluence. For the same electronic energy loss, the velocity of the incident ion could affect the energy and spatial distribution of excited electrons, and therefore effectively modify the diameter of the ion track. Furthermore, nonlinear additive phenomenon of irradiation damage induced by high electronic energy loss in pre-damaged LiNbO3 has been observed. The result indicates that pre-existing damage induced from nuclear energy loss interacts synergistically with inelastic electronic energy loss to promote the formation of amorphous tracks and lead to rapid phase transformation, much more efficient than what is observed in pristine crystal solely induced by electronic energy loss. As a result, this synergistic effect is attributed to the fundamental mechanism that the defects produced by the elastic collisions result in a decrease in thermal conductivity, increase in the electron-phonon coupling, and further lead to higher intensity in thermal spike from intense electronic energy deposition along high-energy ion trajectory.

  8. Nonlinear Elastic Behavior of Piezoelectric Trigonal Crystals: Measurements on Quartz and Lithium-Niobate

    NASA Astrophysics Data System (ADS)

    Latimer, Paul Jerry

    The ultrasonic harmonic generation technique previously used to measure third-order elastic (TOE) constants of crystals of cubic symmetry has been extended to measurement of crystals of trigonal symmetry. The theory for nonpiezoelectric trigonal crystals of J. Philip {Technical Report No. 22, Office of Naval Research, Contract No. N00014 -81-K-0229 (to be published in 1983)} has been combined with the piezoelectric theory of McMahon {J. Acoust. Soc. Am. 44, 1007 (1968)} to determine the effective TOE constants in a piezoelectric solid, and correction has been made in McMahon's expression. Measurements in weakly piezoelectric quartz have produced values of C(,111) and C(,333) which agree within experimental uncertainty with values of R. N. Thurston, H. J. McSkimin and P. Andreatch, Jr. {J. Appl. Phys. 37, 267 (1966)} and R. Stern and R. T. Smith {J. Acoust. Soc. Am. 44, 640 (1968)} after corrections have been made for the effect of diffraction on the data. Measurements in strongly piezoelectric LiNbO(,3) have resulted in values which agree reasonably well with those of J. Philip and M. A. Breazeale {Proc. IEEE Ultrasonics Symposium, Vol. 2 (1982) } but disagree with those of C. Y. Nakagawa, K. Yamanouchi and K. Shibayama {J. Appl. Phys. 44, 3969 (1973) }. There is indication of some sample dependence of the values of both the second-order elastic constants as well as the third-order elastic constants of LiNbO(,3) samples currently available. In the course of measurement of the TOE constants a negative nonlinearity parameter was observed for the Piezoelectric {100} direction in quartz. This peculiarity is impossible for thermodynamic reasons in fluids, but has been observed once previously in fused silica {J. Bains and M. A. Breazeale, J. Acoust, Soc. Am. 57, 745 (1975)}. The nonlinearity parameter appears to be positive for the piezoelectric {001 } direction in LiNbO(,3). The data presented are for the "piezoelectrically stiffened" TOE constants; however, there are preliminary indications that the harmonic generation technique may give access to the constant field TOE constants. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI).

  9. Optical investigation of femtosecond laser induced microstress in neodymium doped lithium niobate crystals

    SciTech Connect

    Rodenas, A.; Sanz Garcia, J. A.; Jaque, D.; Torchia, G. A.; Mendez, C.; Arias, I.; Roso, L.; Agullo-Rueda, F.

    2006-08-01

    The depth-resolved micromodification of single-crystalline femtosecond laser irradiated Nd{sup 3+} doped MgO:LiNbO{sub 3} crystals is investigated by means of micro-Raman and microluminescence experiments. We have found that a permanent tensile stress of the order of 2 GPa is induced in the vicinity of ablated volume as a consequence of the pressure-wave propagation due to the thermoelastic relaxation of the laser irradiated material. Microluminescence experiments have revealed that, as a consequence of the permanent laser induced microstress, a localized redshift of the {sup 4}F{sub 3/2}{yields}{sup 4}I{sub 9/2} luminescence band of Nd{sup 3+} ions also takes place due to a crystal field modification. The analysis of Raman and fluorescence bandwidths indicates that a slight lattice disorder and densification is induced by femtosecond laser irradiation.

  10. Buried amorphous layers by electronic excitation in ion-beam irradiated lithium niobate: Structure and kinetics

    SciTech Connect

    Olivares, J.; Garcia-Navarro, A.; Garcia, G.; Agullo-Lopez, F.; Agullo-Rueda, F.; Garcia-Cabanes, A.; Carrascosa, M.

    2007-02-01

    The formation of buried heavily damaged and amorphous layers by a variety of swift-ion irradiations (F at 22 MeV, O at 20 MeV, and Mg at 28 MeV) on congruent LiNbO{sub 3} has been investigated. These irradiations assure that the electronic stopping power S{sub e}(z) is dominant over the nuclear stopping S{sub n}(z) and reaches a maximum value inside the crystal. The structural profile of the irradiated layers has been characterized in detail by a variety of spectroscopic techniques including dark-mode propagation, micro-Raman scattering, second-harmonic generation, and Rutherford backscattering spectroscopy/channeling. The growth of the damage on increasing irradiation fluence presents two differentiated stages with an abrupt structural transition between them. The heavily damaged layer reached as a final stage is optically isotropic (refractive index n=2.10, independent of bombarding ion) and has an amorphous structure. Moreover, it has sharp profiles and its thickness progressively increases with irradiation fluence. The dynamics under irradiation of the amorphous-crystalline boundaries has been associated with a reduction of the effective amorphization threshold due to the defects created by prior irradiation (cumulative damage). The kinetics of the two boundaries of the buried layer is quite different, suggesting that other mechanisms aside from the electronic stopping power should play a role on ion-beam damage.

  11. Growth mechanism of photoreduced silver nanostructures on periodically proton exchanged lithium niobate: Time and concentration dependence

    NASA Astrophysics Data System (ADS)

    Craig Carville, N.; Manzo, Michele; Denning, Denise; Gallo, Katia; Rodriguez, Brian J.

    2013-05-01

    Photodeposition of metallic nanostructures onto ferroelectric surfaces, which have been chemically patterned using a proton exchange process, has recently been demonstrated. By varying the molar concentration of the AgNO3 solution and the illumination time, one can determine the initial nucleation sites, control the rate of nucleation and the height of silver nanostructures formed, and study the mechanisms by which these processes occurs. The nanoparticles are found to deposit preferentially in the boundary between ferroelectric and proton exchanged regions, in an area proton exchanged via lateral diffusion under the masking layer used for chemical patterning, consistent with our previous results. Using a short illumination time (3 min), we are able to determine that the initial nucleation of the silver nanostructure, having a width of 0.17 ± 0.02 μm and a height of 1.61 ± 0.98 nm, occurs near the edge of the reactive ion etched area within this lateral diffusion region. Over longer illumination times (15 min), we find that the silver deposition has spread to a width of 1.29 ± 0.06 μm, extending across the entire lateral diffusion region. We report that at a high molar concentration of AgNO3 (10-2 M), the amount of silver deposition for 5 min UV illumination is greater (2.88 ± 0.58 nm) compared to that at low (10-4 M) concentrations (0.78 ± 0.35 nm), however, this is not the case for longer time periods. With increasing illumination time (15 min), experiments at 10-4 M had greater overall deposition, 6.90 ± 1.52 nm, compared to 4.50 ± 0.76 nm at 10-2 M. For longer exposure times (30 min) at 10-2 M, the nanostructure height is 4.72 ± 0.59 nm, suggesting a saturation in the nanostructure height. The results are discussed in terms of the electric double layer that forms at the crystal surface. There is an order of magnitude difference between the Debye lengths for 10-2 and 10-4 M solutions, i.e., 3.04 vs. 30.40 nm, which suggests the Debye length plays a role in the availability of Ag+ ions at the surface.

  12. Analysis of Self-Pumped Optical Parametric Interaction for NEODYMIUM:MAGNESIUM OXIDE:LITHIUM Niobate.

    NASA Astrophysics Data System (ADS)

    Prasad, Narasimha Srikantaiah

    With the advent of lasers an era in optics began. Initially, lasers were designed and engineered to generate discrete wavelengths. Subsequent research yielded commercially successful solid state lasers with limited tunability. Triggered by the availability of lasers delivering high intensity, extensive research was carried out in experimental nonlinear optics. In the realm of nonlinear optics, parametric interaction or three wave mixing process has attained significant importance. Nonlinear devices such as optical parametric amplifiers (OPAs) and broadly tunable coherent sources known as optical parametric oscillators (OPOs) were developed based on parametric interaction. Parametric devices normally operate using an intense pump which is external to the device. Currently, research is being conducted to develop highly efficient intra-cavity parametric devices in which the nonlinear crystals is placed inside the laser cavity. Further, advances are being made in semiconductor diode laser (SDL) technology to achieve laser beams of high quality. Considerations include compactness, high efficiency, low power requirements, and cost effectiveness. The desire to replace flash lamps with highly efficient SDLs as optical pump sources and to develop high performance crystalline media have stimulated active areas of research today. The main objective of the present investigation involves the study of three wave mixing processes due to pump radiation that is generated internally inside a crystalline medium. A medium that offers both stimulated emission and parametric gain i.e., a lasing medium that satisfies all the requirements of a parametric process is considered. One such medium that is identified is Nd:MgO:LiNbO _3 crystal. This material is established as a lasing material with excellent electro-optic and nonlinear optical properties. Until now efficient lasing action, internal Q-switching, and self-doubling have been demonstrated. In this study, the requirements to achieve parametric interaction is analytically formulated and experimentally demonstrated using Nd:MgO:LiNbO_3. The results obtained form a sound basis to subsequent analysis of parametric interaction by a pump radiation that is generated internally in the same crystal. Using laser theory and principles of optical parametric interaction, the theory of self-pumped optical parametric interaction is formulated. This encompasses, the requirements of an interaction medium, laser pump generation, Q-switching, cavity analysis, and conditions for parametric interaction. Driven by an internally generated laser pump, the specific processes of optical parametic amplification, optical parametric oscillation, and frequency up-conversion are explored. In this study, novel tuning techniques are considered and spectral performance characteristics of these devices are presented. The design architectures of self-pumped OPO, OPA, and frequency up-converter devices using Nd:MgO:LiNbO _3 crystals are described. It is envisaged that self-pumped parametric devices can outperform present day intra-cavity devices which are bulky and expensive.

  13. First-principles study on phase transition and ferroelectricity in lithium niobate and tantalate

    SciTech Connect

    Toyoura, Kazuaki Ohta, Masataka; Nakamura, Atsutomo; Matsunaga, Katsuyuki

    2015-08-14

    The phase transitions and ferroelectricity of LiNbO{sub 3} and LiTaO{sub 3} have been investigated theoretically from first principles. The phonon analyses and the molecular dynamics simulations revealed that the ferroelectric phase transition is not conventional displacive type but order-disorder type with strong correlation between cation displacements. According to the evaluated potential energy surfaces around the paraelectric structures, the large difference in ferroelectricity between the two oxides results from the little difference in short-range interionic interaction between Nb-O and Ta-O. As the results of the crystal orbital overlap population analyses, the different short-range interaction originates from the difference in covalency between Nb4d-O2p and Ta5d-O2p orbitals, particularly d{sub xz}-p{sub x}/d{sub yz}-p{sub y} orbitals (π orbitals), from the electronic point of view.

  14. Defect-Free, Edge Polishing of Lithium Niobate and Other Optical Crystals.

    DTIC Science & Technology

    1980-11-01

    sawing. (A 10 cm OD. 400 grit diamond blade is used.) The blocking pitch consists of I part Montan wax. I part beeswax and 2 parts rosin. Its melting...rosin, beeswax , paraffin, pitch and other waxes. Polishing abrasives such as Microgrit aluminas; Cabosil; Linde A, B and C; diamond powders (1/4 p...pitch (containing 3 parts rosin, I part beeswax and 1 part light Montan wax) is easily melted by touching it to the surface of the tool (approximately

  15. Phase-shifting holography using Bragg and non-Bragg orders in photorefractive lithium niobate

    NASA Astrophysics Data System (ADS)

    Abeywickrema, Ujitha; Banerjee, Partha

    2014-09-01

    Holographic interferometry is an effective and rich method for measuring very small (order of a wavelength) deformations of an object and is widely used for non-destructive testing. In this work, the use of photorefractive materials for implementing real time phase shifting holographic interferometry is examined in detail. Bragg and non-Bragg orders generated during two- and multi-beam coupling in a photorefractive material can be used to retrieve the deformation of the object, or the phase information of the object. In previous work, it has been shown that object deformation can be determined from monitoring Bragg and non-Bragg orders. Preliminary experiments for determining the depth profile of an object have been reported, along with approximate analytic solutions for the Bragg and non-Bragg orders for the case of interacting plane waves. In this work, the exact solutions of Bragg and non-Bragg orders are found from numerically solving the interaction equations in a photorefractive material. It is shown that if the grating written in the material using two waves is read out by a reference and the object, the resulting Bragg and non-Bragg orders contain the information of the object phase, and is dependent on material parameters and the writing and reading beam intensities. Similarities and differences between this dynamic holographic technique and the traditional phase shifting digital holography are extensively discussed.

  16. Shaping the light distribution with facet designs in lithium niobate nanowaveguides

    NASA Astrophysics Data System (ADS)

    Reig Escalé, Marc; Sergeyev, Anton; Geiss, Reinhard; Grange, Rachel

    2017-08-01

    The miniaturization of coherent light sources down to the nanoscale demands unrestricted freedom of designs enabled by full control of the material dimensions. One way to transfer bulky applications to the nanoscale is using nanowaveguides, which guide light confined to sub-micron mode sizes. In order to further develop nanowaveguide-based applications such as optical integrated circuits, spectrometers, or local light delivery, it is necessary to have full control of the out-coupled light distribution. Here, we show that the nanowaveguide (NW) facet geometry can be used to shape the light distribution. We experimentally show the influence of the facet in the emission spatial spectrum and, later, we theoretically investigate five different facet designs for shaping the emitted light spatial spectrum. These designs present a diversity of options for manipulating the light distribution. For instance, one design shows large angular light deflection (more than 80° in the radial direction), which is relevant for integrated circuits. A second design shows homogeneous spreading across the normal direction with azimuthal selectivity, which is suitable for local light delivery applications since it acts like a point-source at the facet of the nanowaveguide.

  17. [Calculation of spectroscopic parameters of highly doped Er3+ in lithium niobate].

    PubMed

    Sun, Dun-lu; Zhang, Qing-li; Wang, Ai-hua; Hang, Yin; Zhang, Lian-han; Qian, Xiao-bo; Zhu, Shi-ning; Yin, Shao-tang

    2005-09-01

    A highly doped Er3+: LiNbO3 (concentration 6 mol%) crystal was grown successfully by Czochralski method. The crystal is higher than that of the lowly doped Er3+ in LiNbO3 crystal, which is helpful to improve absorption coefficient of the grown the pumping efficiency. The absorption spectra at two unpolarized directions (X and Z) and two polarized directions (E parallel Z, E perpendicular Z) were measured. Using the Judd-Ofelt theory, and according to the measured absorption spectra, the intensity parameters omegalambda of Er3+ were fitted. The results of root-mean square (r. m. s) deviation show that the error of polarized fitting is less than that of unpolarized one. Thus fluorescence transition probabilities (Ajj), radioactive lifetime (tau), fluorescence branching ratio (beta), and integrated emission cross section (sigmap) were calculated and accepted according to the polarized results, and were also discussed and compared with the ones reported in the literature.

  18. Impact of longitudinal fields on second harmonic generation in lithium niobate nanopillars

    NASA Astrophysics Data System (ADS)

    Baghban, Mohammad Amin; Gallo, Katia

    2016-09-01

    An optimized focused ion beam process is used to fabricate micrometer-long LiNbO3 nanopillars with diameters varying between 150 and 325 nm. Polarimetric mappings of second harmonic generation from a wavelength of 850 nm demonstrate the ability to modify the polarization features of the nonlinear response through a fine adjustment of the pillar size. The effect is ascribed to the non-negligible contribution of the longitudinal fields associated with sub-wavelength light confinement in the LiNbO3 nanopillars. The results also highlight the importance of a fine control over the nanopillar size in order to effectively engineer their nonlinear response.

  19. Electric Field Induced Ferroelectric Microdomain Inversion on X- and Y-Cut Lithium Niobate,

    DTIC Science & Technology

    generation of inverted microdomains are applicable only on +/-Z-faces of LiNbO3 1,2,3. For +/-Y- cut material we recently demonstrated periodical...was successfully applied not only to Y- cut , but also - for the first time - to X- cut crystals. The depth of the domains could be increased up to 1.8 micrometer.

  20. Design of focused single-element (50 to 100 MHz) transducers using lithium niobate

    NASA Astrophysics Data System (ADS)

    Cannata, Jonathan M.; Ritter, Timothy A.; Chen, WoHsing; Shung, K. Kirk

    2001-05-01

    This paper discusses two fabrication procedures used to build LiNbO3 single element ultrasonic transducers with center frequencies in the 50-100 MHz range. Transducers of varying dimensions were built for an f-number range of 1.5- 3.0. A conductive quarter wavelength silver epoxy matching layer, and a conductive silver epoxy backing, were used in all designs. The desired focal depths were achieved by either casting an acoustic lens on the transducer face or press-focusing the piezoelectric into a spherical curvature. For lens-focusing transducers the lens material EPO-TEK 301 was modeled as a second matching layer. The pressed-focused transducer design utilized parylene as the second matching layer. For devices that required electrical impedance matching, a low impedance transmission line coaxial cable was used. All transducers were tested in a pulse-echo insertion loss arrangement, whereby the center frequency, bandwidth, insertion loss, and focal depth were measured. Several transducers were fabricated with center frequencies in the 50 to 100 MHz range. The measured -6dB bandwidths and two-way insertion loss values ranged from 33% to 70% and 12.5dB to 23.0dB, respectively. Both the lens-focusing and press-focusing techniques were successful in producing the desired focal depth without significantly compromising device sensitivity and bandwidth.

  1. Long-term large-scale holographic storage in iron doped lithium niobate

    NASA Astrophysics Data System (ADS)

    An, Xin

    1998-11-01

    The centerpiece of my work described in this thesis is a large-scale fast random-access holographic memory using LiNbO3:Fe. This system is described in detail in Chapter 2 and 3 and has been used repeatedly and extensively through all of our works. In Chapter 2, various design issues related to this system are discussed. High, system dynamic-range-limited storage capacity is demonstrated by using angle, fractal and spatial multiplexing with a key custom-designed component-the segmented mirror array. The SNR and BER obtained from the reconstructed information are comparable to those of conventional CD-ROMs. Fast random access to the memory contents is materialized in a separate system using an acousto-optic deflector (AOD) as the addressing device and an electro-optic modulator (EOM) to compensate for the Doppler shift. Chapter 3 discusses the design issues and presents experimental demonstration of holographic storage using the system. The design and application of an optical phase-lock loop using the AOD and EOM for phase stabilization are also described at the end of this chapter. Chapter 4 and 5 address two methods of thermal fixing to solve the volatility problem in holographic memories using photorefractive materials. First, 'Low-High-Low' fixing is described in Chapter 4, along with the characterization of system error performance of non- volatile holographic storage using thermal fixing. A novel 'incremental fixing schedule' is introduced to improve the system fixing efficiency. Experimental demonstration of a large-scale non-volatile memory with good error performance is also presented. Chapter 5 shows theoretical treatment and experimental demonstration of high-temperature recording in LiNbO3:Fe. Different charge transport mechanisms and their influence on the dynamics of holographic recording as well as the system dynamic range are discussed in detail. The two thermal fixing methods are examined and compared in terms of the M/#. In Chapter 6, a very important holographic noise source, the inter-pixel grating noise, is evaluated theoretically based on a linear (small-signal) model, followed by experimental investigation of its influence on the system error performance of a large-scale memory. Random-phase modulation in the signal beam is discussed and demonstrated as an effective way to suppress this holographic noise.

  2. Characterization of iron-doped lithium niobate for holographic storage applications

    NASA Technical Reports Server (NTRS)

    Shah, R. R.; Kim, D. M.; Rabson, T. A.; Tittel, F. K.

    1976-01-01

    A comprehensive characterization of chemical and holographic properties of eight systematically chosen Fe:LiNbO3 crystals is performed in order to determine optimum performance of the crystals in holographic storage and display applications. The discussion covers determination of Fe(2+) and Fe(3+) ion concentrations in Fe:LiNbO3 system from optical absorption and EPR measurements; establishment of the relation between the photorefractive sensitivity of Fe(2+) and Fe(3+) concentrations; study of the spectral dependence, the effect of oxygen annealing, and of other impurities on the photorefractive sensitivity; analysis of the diffraction efficiency curves for different crystals and corresponding sensitivities with the dynamic theory of hologram formation; and determination of the bulk photovoltaic fields as a function of Fe(2+) concentrations. In addition to the absolute Fe(2+) concentration, the relative concentrations of Fe(2+) and Fe(3+) ions are also important in determining the photorefractive sensitivity. There exists an optimal set of crystal characteristics for which the photorefractive sensitivity is most favorable.

  3. The role of alkali additives in the crystallization of ferroelectric potassium lithium niobate crystals

    NASA Astrophysics Data System (ADS)

    Péter, Á.; Hajdara, I.; Szaller, Zs.; Lengyel, K.; Kovács, L.

    2013-05-01

    Ferroelectric K3Li2Nb5O15 (KLN-1) crystals have been grown by the top-seeded solution growth method from pure, Na+, Rb+ and Cs+ doped melt. The impact of alkali additives was assessed all over the entire pulling range by investigating the variation of the structural and physical properties by using spectroscopic and dielectric methods. The incorporation of alkali homologs has been correlated with their ionic radii: Na+ ions were found to enter both Li and K sites with high segregation coefficient (k˜1.6), Rb+ ions were detected only at K sites (k˜0.34) and Cs+ ions practically did not incorporate into the lattice (k˜0.12). Alkali additives have been found to play a dual role in the growth process by affecting the crystallization temperature and promoting the K and Li site occupancy. By decreasing the crystallization temperature the Cs2O additive reduced the concentration both of the antisite Nb ions at Li site and that of alkali vacancies; therefore it can be considered as a promising fluxing agent in the growth of KLN crystals.

  4. Electro-optic properties of indium/erbium-codoped lithium niobate crystal for integrated optics

    NASA Astrophysics Data System (ADS)

    Du, Wan-Ying; Zhang, Zi-Bo; Ren, Shuai; Wong, Wing-Han; Yu, Dao-Yin; Pun, Edwin Yue-Bun; Zhang, De-Long

    2017-02-01

    Clamped and unclamped electro-optic coefficients γ13 and γ33 of In3+/Er3+-codoped LiNbO3 crystals, which were grown by Czochralski method from the melts containing 0.5 mol% Er2O3 while varied In2O3 contents of 0.0, 0.5, 1.0 and 1.5 mol%, were measured by Mach-Zehnder interferometry. The results show that In3+/Er3+ codoping does not cause change of γ13 and γ33, and both γ13 and γ33 can be regarded as unchanged in the studied In3+ concentration range of 0-2.6 mol% (in crystal) within the experimental error of 3%. The small doping effect is desired in light of the electro-optic application of the crystal. A qualitative, comprehensible explanation for the small effect is given on the basis of the EO coefficient model of LiNbO3 and doping effect on the defect structure of LiNbO3.

  5. Reaping the benefits of ferroelectricity in selectively precipitated lithium niobate microcrystals in silica matrix for photocatalysis

    NASA Astrophysics Data System (ADS)

    Rastogi, Monisha; Chauhan, Aditya; Kushwaha, Himmat Singh; Kumar, Ramachandran Vasant; Vaish, Rahul

    2016-11-01

    Microcrystals of LiNbO3 (size ˜200 nm) can be selectively precipitated in a glass matrix which can assist in the photocatalytic activity through ferroelectricity. Glass with the composition 30SiO2-35Li2CO3-35Nb2O5 was utilized for the process. A remarkably high Estriol (E3) degradation rate of 232.54 min-1 m-2 was obtained. The degradation was monitored using fluorescence spectroscopy with a detection limit in nanomolar (nM) range. From the fitting of fluorescence intensity versus time, it was observed that degradation of estriol follows a pseudo first-order reaction kinetics. The results indicate that LiNbO3 based glass-ceramics have a great potential to be employed as a well embedded photocatalyst.

  6. Humidity effects on tip-induced polarization switching in lithium niobate

    SciTech Connect

    Ievlev, A. V.; Morozovska, A. N.; Shur, V. Ya.; Kalinin, S. V.

    2014-03-03

    In the last several decades, ferroelectrics have attracted much attention as perspective materials for nonlinear optics and data storage devices. Scanning probe microscopy (SPM) has emerged as a powerful tool both for studies of domain structures with nanoscale spatial resolution and for writing the isolated nanodomains by local application of the electric field. Quantitative analysis of the observed behavior requires understanding the role of environmental factors on imaging and switching process. Here, we study the influence of the relative humidity in the SPM chamber on tip-induced polarization switching. The observed effects are attributed to existence of a water meniscus between the tip and the sample surface in humid atmosphere. These results are important for a deeper understanding of complex investigations of ferroelectric materials and their applications and suggest the necessity for fundamental studies of electrocapillary phenomena at the tip-surface junction and their interplay with bias-induced materials responses.

  7. Humidity effects on tip-induced polarization switching in lithium niobate

    SciTech Connect

    Ievlev, Anton; Morozovska, A. N.; Shur, Vladimir Ya.; Kalinin, Sergei V

    2014-01-01

    In the last several decades, ferroelectrics have attracted much attention as perspective materials for nonlinear optics and data storage devices. Scanning probe microscopy (SPM) has emerged as a powerful tool both for studies of domain structures with nanoscale spatial resolution and for writing the isolated nanodomains by local application of the electric field. Quantitative analysis of the observed behavior requires understanding the role of environmental factors on imaging and switching process. Here we study the influence of the relative humidity in the SPM chamber on tip-induced polarization switching. The observed effects are attributed to existence of a water meniscus between the tip and the sample surface in humid atmosphere. These results are important for a deeper understanding of complex investigations of ferroelectric materials and their applications, and suggest the necessity for fundamental studies of electrocapillary phenomena at the tip-surface junction and their interplay with bias-induced materials responses.

  8. A tunable, Nd-doped lithium niobate laser at 1084 nm

    SciTech Connect

    Schearer, L.D. ); Leduc, M.

    1988-10-01

    Over 250 mW of CW laser emission at 1084 nm is obtained from Nd:LiNbO{sub 3} when the rod is end-pumped along the crystalline {open quote}{ital y}{close quote} axis by 1 W from a Kr{sup +} laser at 752 nm. The laser can be tuned over 3 nm at the 1084 nm peak with a thin, uncoated etalon in the cavity. Thresholds of 30 mW of absorbed pump power were obtained with a weak output coupler, rising to 220 mW with a 35% transmitting output mirror. No pump-induced photorefractive effects were observed.

  9. Periodically structured plasmonic waveguides

    NASA Astrophysics Data System (ADS)

    Saj, W. M.; Foteinopoulou, S.; Kafesaki, M.; Soukoulis, C. M.; Economou, E. N.

    2008-04-01

    We study surface plasmon polariton (SPP) guiding structures, which are a modification of the Metal-Insulator-Metal (MIM) waveguide. The designs are constructed by introducing a periodic modulation in a MIM waveguide, with a glass core and silver claddings. This periodic modulation is created either by causing periodic indentations in the silver slabs encompassing the glass core, or by increasing the glass spacer material in certain periodic locations. Our objective is to achieve long range sub-wavelength waveguiding with vast dispersion engineering capabilities. We employ the Finite Difference Time Domain Method (FDTD) with the Auxiliary Differential Equation method (ADE) for the calculation of the dispersion relation of the guided modes, as well as the real time propagation suggests that the guiding mechnism in the examined structures is based on the electromagnetic (EM) couping between the slit plasmon modes. These - depending on the design - exist in the grooves between the silver plates or in the larger areas of the glass core spacer. Put it different, the guiding mechanism in the examined SPP waveguide designs is analogous to the EM energy transfer along metallic nanoparticle chains.

  10. Gratings in polymeric waveguides

    NASA Astrophysics Data System (ADS)

    Mishakov, G.; Sokolov, V.; Kocabas, A.; Aydinli, A.

    2007-04-01

    Laser-induced formation of polymer Bragg grating filters for Dense Wavelength Division Multiplexing (DWDM) applications is discussed. Acrylate monomers halogenated with both fluorine and chlorine, which possess absorption losses less than 0.25 dB/cm and wide choice of refractive indices (from 1.3 to 1.5) in the 1.5 μm telecom wavelength region were used. The monomers are highly intermixable thus permitting to adjust the refractive index of the composition within +/-0.0001. Moreover they are photocurable under UV exposure and exhibit high contrast in polymerization. These properties make halogenated acrylates very promising for fabricating polymeric waveguides and photonic circuits. Single-mode polymer waveguides were fabricated on silicon wafers using resistless contact lithography. Submicron index gratings have been written in polymer waveguides using holographic exposure with He-Cd laser beam (325 nm) through a phase mask. Both uniform and apodized gratings have been fabricated. The gratings are stable and are not erased by uniform UV exposure. The waveguide gratings possess narrowband reflection spectra in the 1.5 μm wavelength region of 0.4 nm width, nearly rectangular shape of the stopband and reflectivity R > 99%. The fabricated Bragg grating filters can be used for multiplexing/demultiplexing optical signals in high-speed DWDM optical fiber networks.

  11. Synthesis of transparent aqueous sols of colloidal layered niobate nanocrystals at room temperature.

    PubMed

    Ban, Takayuki; Yoshikawa, Shogo; Ohya, Yutaka

    2011-12-01

    Transparent aqueous sols of colloidal tetramethylammonium niobate nanocrystals were synthesized by mixing tetramethylammonium hydroxide (TMAOH), niobium ethoxide, and water at TMAOH/Nb≥0.7 at room temperature. The X-ray diffraction patterns of the thin films prepared by evaporating the colloidal solutions on a glass substrate indicated that the colloidal niobate had a layered crystalline structure. Two types of layered structures are known as a layered niobate, i.e. M(4)Nb(6)O(17)·nH(2)O and MNb(3)O(8) (M=H, H(3)O, or alkaline metal). Raman spectra and electron diffraction suggested that the niobate nanocrystals were similar in crystal structure to M(4)Nb(6)O(17)·nH(2)O compounds. Moreover, when niobium oxide thin films were fabricated from the niobate colloidal solutions by the sol-gel method, oriented T-Nb(2)O(5) thin films, whose c-axis was parallel to the substrate surface, were obtained. The orientation of the thin films was probably attributed to the layered structure of the colloidal niobate nanocrystals. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. On the nature of striae in strontium barium niobate

    SciTech Connect

    Monchamp, R.R.; Mihalik, G.B.; Franks, L.A.

    1993-12-31

    Strontium barium niobate crystals were grown by the Czochralski technique. These crystals were 15--20 mm in diameter and 25 to 75 mm long. Two types stride, designated as coarse and fine, were characterized. The coarse stride are optically dense and are spaced by 100 to 500 {mu}m apart; the fine striae are optically less dense and spaced 5--50 {mu}m apart. The origins of the stride are attributed to thermal fluctuations in the melt related to the control system and to rotation of the growing crystal in non-isothermal radial gradients. Analysis of the crystals would indicated that the coarse striae may contain increased concentrations of sodium.

  13. Nonlinear optical properties of calcium barium niobate epitaxial thin films.

    PubMed

    Bancelin, Stéphane; Vigne, Sébastien; Hossain, Nadir; Chaker, Mohammed; Légaré, François

    2016-07-25

    We investigate the potential of epitaxial calcium barium niobate (CBN) thin film grown by pulsed laser deposition for optical frequency conversion. Using second harmonic generation (SHG), we analyze the polarization response of the generated signal to determine the ratios d15 / d32 and d33 / d32 of the three independent components of the second-order nonlinear susceptibility tensor in CBN thin film. In addition, a detailed comparison to the signal intensity obtained in a y-cut quartz allows us to measure the absolute value of these components in CBN thin film: d15 = 5 ± 2 pm / V, d32 = 3.1 ± 0.6 pm / V and d33 = 9 ± 2 pm / V.

  14. Preparation and piezoelectric properties of potassium sodium niobate glass ceramics

    NASA Astrophysics Data System (ADS)

    Jiang, Shan; Wang, Xuan-Ming; Li, Jia-Yu; Zhang, Yong; Zheng, Tao; Lv, Jing-Wen

    2015-06-01

    This paper describes the preparation of a piezoelectric glass ceramic material from potassium sodium niobate (K0.5Na0.5NbO3; KNN) using a novel melting method. The effects of the subsequent heat-treatment on the optical, thermal, electrical, and mechanical properties of the material are carefully examined, and its crystal structure and surface morphology are characterized respectively by x-ray diffraction and scanning electron microscopy. This new material has a much higher piezoelectric coefficient (163 pC·N-1) than traditional piezoelectric ceramics (131 pC·N-1). On this basis therefore, a strategy for the future study and development of lead-free KNN-based piezoelectric glass ceramics is proposed.

  15. Laser Physics and Laser Spectroscopy

    DTIC Science & Technology

    1990-04-01

    lithium niobate waveguides A technique based on in- diffusion of lithographically patterned Ti films into lithium niobate substrates was developed to...treatment, the Ti is diffused into the substrate, which, on cooling to room temperature, leads to an array of periodically reversed ferroelectric... titanium that induces the domain 9 . 10 ’_ 5 0 0 0 820 821 822 Wavelength (nm Figure 3: Wavelength tuning curve for second harmonic generation of 410 nm

  16. Laser-assisted controlled in-diffusion processes for preparation of optical waveguides and ultrashallow semiconductor junctions

    NASA Astrophysics Data System (ADS)

    Dinescu, Maria; Chitica, N.; Lita, Adriana; Pantelica, D.; Bucur, B.; Ferrari, A.; Maiello, Gabriella; Bertolotti, Mario; Michailova, Galina; Gerardi, C.; Giorgi, Rossella; Dekonimos-Makris, T.; Montecchi, Marco

    1995-03-01

    We present new results in the laser doping of two materials of major interest for applications: LiNbO3 and Si. In both cases a solid dopant source was used. Using a free running ruby laser, we have doped single crystalline lithium niobate with Ti down to 1.5 micrometers . A step- like Ti profile was determined by Rutherford BAckscattering Spectrometry. Irradiating with a cw CO2 laser Si wafers coated with a P-containing paste, n-p junctions were obtained.

  17. Lithium in 2012

    USGS Publications Warehouse

    Jaskula, B.W.

    2013-01-01

    In 2012, estimated world lithium consumption was about 28 kt (31,000 st) of lithium contained in minerals and compounds, an 8 percent increase from that of 2011. Estimated U.S. consumption was about 2 kt (2,200 st) of contained lithium, the same as that of 2011. The United States was thought to rank fourth in consumption of lithium and remained the leading importer of lithium carbonate and the leading producer of value-added lithium materials. One company, Rockwood Lithium Inc., produced lithium compounds from domestic brine resources near Silver Peak, NV.

  18. Experimental investigation of plasmofluidic waveguides

    SciTech Connect

    Ku, Bonwoo; Kwon, Min-Suk; Shin, Jin-Soo

    2015-11-16

    Plasmofluidic waveguides are based on guiding light which is strongly confined in fluid with the assistance of a surface plasmon polariton. To realize plasmofluidic waveguides, metal-insulator-silicon-insulator-metal (MISIM) waveguides, which are hybrid plasmonic waveguides fabricated using standard complementary metal-oxide-semiconductor technology, are employed. The insulator of the MISIM waveguide is removed to form 30-nm-wide channels, and they are filled with fluid. The plasmofluidic waveguide has a subwavelength-scale mode area since its mode is strongly confined in the fluid. The waveguides are experimentally characterized for different fluids. When the refractive index of the fluid is 1.440, the plasmofluidic waveguide with 190-nm-wide silicon has propagation loss of 0.46 dB/μm; the coupling loss between it and an ordinary silicon photonic waveguide is 1.79 dB. The propagation and coupling losses may be reduced if a few fabrication-induced imperfections are removed. The plasmofluidic waveguide may pave the way to a dynamically phase-tunable ultracompact device.

  19. Gap plasmon excitation in plasmonic waveguide using Si waveguide

    NASA Astrophysics Data System (ADS)

    Okuda, Koji; Kamada, Shun; Okamoto, Toshihiro; Haraguchi, Masanobu

    2016-08-01

    Plasmonic waveguides have attracted considerable attention for application in highly integrated optical circuits since they can confine light to areas smaller than the diffraction limit. In this context, in order to realize a highly integrated optical circuit, we fabricate and evaluate the optical characteristics of a poly(methyl methacrylate) junction positioned between Si and plasmonic waveguides. For the plasmonic waveguide, we employ a gap plasmonic waveguide in which the energy of the plasmonic wave can be confined in order to reduce the scattering loss at the junction. By experimental measurement, we determine the coupling efficiency between the Si and gap plasmonic waveguides and the propagation length at the gap plasmonic waveguide to be 52.4% and 11.1 µm, respectively. These values agree with those obtained by the three-dimensional finite-difference time-domain simulation. We believe that our findings can significantly contribute to the development of highly integrated optical circuits.

  20. The waveguide laser - A review

    NASA Technical Reports Server (NTRS)

    Degnan, J. J.

    1976-01-01

    The present article reviews the fundamental physical principles essential to an understanding of waveguide gas and liquid lasers, and the current technological state of these devices. At the present time, waveguide laser transitions span the visible through submillimeter regions of the wavelength spectrum. The introduction discusses the many applications of waveguide lasers and the wide variety of laser configurations that are possible. Section 1 summarizes the properties of modes in hollow dielectric waveguides of circular, rectangular, and planar cross section. Section 2 considers various approaches to optical feedback including internal and external mirror Fabry-Perot type resonators, hollow waveguide distributed feedback structures, and ring-resonant configurations. Section 3 discusses those aspects of molecular kinetic and laser theory pertinent to the design and optimization of waveguide gas lasers.

  1. Phonon waveguides for electromechanical circuits.

    PubMed

    Hatanaka, D; Mahboob, I; Onomitsu, K; Yamaguchi, H

    2014-07-01

    Nanoelectromechanical systems (NEMS), utilizing localized mechanical vibrations, have found application in sensors, signal processors and in the study of macroscopic quantum mechanics. The integration of multiple mechanical elements via electrical or optical means remains a challenge in the realization of NEMS circuits. Here, we develop a phonon waveguide using a one-dimensional array of suspended membranes that offers purely mechanical means to integrate isolated NEMS resonators. We demonstrate that the phonon waveguide can support and guide mechanical vibrations and that the periodic membrane arrangement also creates a phonon bandgap that enables control of the phonon propagation velocity. Furthermore, embedding a phonon cavity into the phonon waveguide allows mobile mechanical vibrations to be dynamically switched or transferred from the waveguide to the cavity, thereby illustrating the viability of waveguide-resonator coupling. These highly functional traits of the phonon waveguide architecture exhibit all the components necessary to permit the realization of all-phononic NEMS circuits.

  2. Symmetric Waveguide Orthomode Junctions

    NASA Technical Reports Server (NTRS)

    Wollack, E. J.; Grammer, W.

    2003-01-01

    Imaging applications at millimeter and submillimeter wavelengths demand precise characterization of the amplitude, spectrum, and polarization of the electromagnetic radiation. The use of a waveguide orthomode transducer (OMT) can help achieve these goals by increasing spectral coverage and sensitivity while reducing exit aperture size, optical spill, instrumental polarization offsets, and lending itself to integration in focal plane arrays. For these reasons, four-fold symmetric OMTs are favored over a traditional quasi-optical wire grid for focal plane imaging arrays from a systems perspective. The design, fabrication, and test of OMTs realized with conventional split-block techniques for millimeter wave-bands are described. The design provides a return loss is -20 dB over a full waveguide band (40% bandwidth), and the cross-polarization and isolation are greater than -40 dB for tolerances readily achievable in practice. Prototype examples realized in WR10.0 and WR3.7 wavebands will be considered in detail.

  3. Symmetric Waveguide Orthomode Junctions

    NASA Technical Reports Server (NTRS)

    Wollack, E. J.; Grammer, W.

    2003-01-01

    Imaging applications at millimeter and submillimeter wavelengths demand precise characterization of the amplitude, spectrum, and polarization of the electromagnetic radiation. The use of a waveguide orthomode transducer (OMT) can help achieve these goals by increasing spectral coverage and sensitivity while reducing exit aperture size, optical spill, instrumental polarization offsets, and lending itself to integration in focal plane arrays. For these reasons, four-old symmetric OMTs are favored over a traditional quasi-optical wire grid for focal plane imaging arrays from a systems perspective. The design, fabrication, and test of OMTs realized with conventional split-block techniques for millimeter wave-bands are described. The design provides a return loss is -20 dB over a full waveguide band (40% bandwidth), and the cross-polarization and isolation are greater than -40 dB for tolerances readily achievable in practice. Prototype examples realized in WR10.0 and WR3.7 wavebands will be considered in detail.

  4. Waveguide optical microscopy

    NASA Astrophysics Data System (ADS)

    Egorov, Alexandre A.

    1997-08-01

    The theoretical aspects of the light scattering on the statistical irregularities of the planar optical waveguide are described. The analysis of direct and inverse light scattering problems is accomplished. The theoretical investigation predicts: the lateral resolution can attain approximately 20 nm and the vertical resolution (in rms height) can attain approximately 1 angstrom. The limiting lateral resolution is a approximately 15-times less than Abbe's diffraction limit. Thus the superresolution may be accomplished by the waveguide optical microscopy (WOM). The increasing of WOM's resolution depends on a-priori information of the irregularities and on a sufficiently high signal-to-noise ratio. A possible using of WOM for bioecological researchers has been mentioned.

  5. Wakefield in a waveguide

    NASA Astrophysics Data System (ADS)

    Bliokh, Y. P.; Leopold, J. G.; Shafir, G.; Shlapakovski, A.; Krasik, Ya. E.

    2017-06-01

    The feasibility of an experiment which is being set up in our plasma laboratory to study the effect of a wakefield formed by an ultra-short (≤10-9 s) high-power (˜1 GW) microwave (10 GHz) pulse propagating in a cylindrical waveguide filled with an under-dense [(2-5) × 1010 cm-3] plasma is modeled theoretically and simulated by a particle in cell code. It is shown that the radial ponderomotive force plays a circular key role in the wakefield formation by the TM mode waveguide. The model and the simulations show that powerful microwave pulses produce a wakefield at lower plasma density and electric field gradients but larger space and time scales compared to the laser produced wakefield in plasmas, thus providing a more accessible platform for the experimental study.

  6. Microwave waveguide manifold and method

    DOEpatents

    Staehlin, John H.

    1987-01-01

    A controllably electrically coupled, physically intersecting plural waveguide manifold assembly wherein the intersecting waveguide elements are fabricated in integral unitary relationship from a single piece of metal in order to avoid the inaccuracies and difficult-to-control fabrication steps associated with uniting separate waveguide elements into a unitary structure. An X-band aluminum airborne radar manifold example is disclosed, along with a fabrication sequence for the manifold and the electrical energy communicating apertures joining the manifold elements.

  7. Microwave waveguide manifold and method

    DOEpatents

    Staehlin, John H.

    1987-12-01

    A controllably electrically coupled, physically intersecting plural waveguide manifold assembly wherein the intersecting waveguide elements are fabricated in integral unitary relationship from a single piece of metal in order to avoid the inaccuracies and difficult-to-control fabrication steps associated with uniting separate waveguide elements into a unitary structure. An X-band aluminum airborne radar manifold example is disclosed, along with a fabrication sequence for the manifold and the electrical energy communicating apertures joining the manifold elements.

  8. Evaluation of waveguide coating materials

    NASA Technical Reports Server (NTRS)

    Chen, W. C. J.; Baker, B. W.

    1982-01-01

    Waveguide coating materials were tested at 8470 MHz for insertion loss. Samples of these coatings on waveguide pieces without flanges were tested in an environmental chamber to simulate the effects of high power microwave heating. Test results indicated that three types of coating materials are acceptable with regard to insertion loss. However, simulated microwave heating caused debonding of Metcot 7 and BD-991 coatings, resulting in peelings in the waveguide. The higher cost Chemglaze R104 does not exhibit this problem.

  9. Analysis of Helical Waveguide.

    DTIC Science & Technology

    1985-12-23

    tube Efficiency Helix structure Backward wave oscillation Gain 19. ABSTRACT (Continue on reverse if necessary and identofy by block number) The...4,vailabilitY CCdes -vai aidIorDist spec a ." iii "- -. .5- S.. . ANALYSIS OF HELICAL WAVEGUIDE I. INTRODUCTION High power (- 10 kW) and broadband ...sys- tems. The frequency range of interest is 60-100 GHz. In this frequency range, the conventional slow wave circuits such as klystrons and TWTs have

  10. Investigation of Truncated Waveguides

    NASA Technical Reports Server (NTRS)

    Lourie, Nathan P.; Chuss, David T.; Henry, Ross M.; Wollack, Edward J.

    2013-01-01

    The design, fabrication, and performance of truncated circular and square waveguide cross-sections are presented. An emphasis is placed upon numerical and experimental validation of simple analytical formulae that describe the propagation properties of these structures. A test component, a 90-degree phase shifter, was fabricated and tested at 30 GHz. The concepts explored can be directly applied in the design, synthesis and optimization of components in the microwave to sub-millimeter wavebands.

  11. Photonic Waveguide Choke Joint with Absorptive Loading

    NASA Technical Reports Server (NTRS)

    Wollack, Edward J. (Inventor); U-Yen, Kongpop (Inventor); Chuss, David T. (Inventor)

    2016-01-01

    A photonic waveguide choke includes a first waveguide flange member having periodic metal tiling pillars, a dissipative dielectric material positioned within an area between the periodic metal tiling pillars and a second waveguide flange member disposed to be coupled with the first waveguide flange member and in spaced-apart relationship separated by a gap. The first waveguide flange member has a substantially smooth surface, and the second waveguide flange member has an array of two-dimensional pillar structures formed therein.

  12. Cup Cylindrical Waveguide Antenna

    NASA Technical Reports Server (NTRS)

    Acosta, Roberto J.; Darby, William G.; Kory, Carol L.; Lambert, Kevin M.; Breen, Daniel P.

    2008-01-01

    The cup cylindrical waveguide antenna (CCWA) is a short backfire microwave antenna capable of simultaneously supporting the transmission or reception of two distinct signals having opposite circular polarizations. Short backfire antennas are widely used in mobile/satellite communications, tracking, telemetry, and wireless local area networks because of their compactness and excellent radiation characteristics. A typical prior short backfire antenna contains a half-wavelength dipole excitation element for linear polarization or crossed half-wavelength dipole elements for circular polarization. In order to achieve simultaneous dual circular polarization, it would be necessary to integrate, into the antenna feed structure, a network of hybrid components, which would introduce significant losses. The CCWA embodies an alternate approach that entails relatively low losses and affords the additional advantage of compactness. The CCWA includes a circular cylindrical cup, a circular disk subreflector, and a circular waveguide that serves as the excitation element. The components that make it possible to obtain simultaneous dual circular polarization are integrated into the circular waveguide. These components are a sixpost polarizer and an orthomode transducer (OMT) with two orthogonal coaxial ports. The overall length of the OMT and polarizer (for the nominal middle design frequency of 2.25 GHz) is about 11 in. (approximately equal to 28 cm), whereas the length of a commercially available OMT and polarizer for the same frequency is about 32 in. (approximately equal to 81 cm).

  13. Folded waveguide coupler

    DOEpatents

    Owens, Thomas L.

    1988-03-01

    A resonant cavity waveguide coupler for ICRH of a magnetically confined plasma. The coupler consists of a series of inter-leaved metallic vanes disposed withn an enclosure analogous to a very wide, simple rectangular waveguide that has been "folded" several times. At the mouth of the coupler, a polarizing plate is provided which has coupling apertures aligned with selected folds of the waveguide through which rf waves are launched with magnetic fields of the waves aligned in parallel with the magnetic fields confining the plasma being heated to provide coupling to the fast magnetosonic wave within the plasma in the frequency usage of from about 50-200 mHz. A shorting plate terminates the back of the cavity at a distance approximately equal to one-half the guide wavelength from the mouth of the coupler to ensure that the electric field of the waves launched through the polarizing plate apertures are small while the magnetic field is near a maximum. Power is fed into the coupler folded cavity by means of an input coaxial line feed arrangement at a point which provides an impedance match between the cavity and the coaxial input line.

  14. Waveguide mutually pumped phase conjugators.

    PubMed

    James, S W; Youden, K E; Jeffrey, P M; Eason, R W; Chandler, P J; Zhang, L; Townsend, P D

    1993-09-20

    The operation of the bridge mutually pumped phase conjugator is reported in a planar waveguide structure in photorefractive BaTiO(3). The waveguide was fabricated by the technique of ion implantation, using 1.5-MeVH(+) ions at a dose of 10(16) ions/cm(2). An order of magnitude decrease in response time is observed in the waveguide as compared with typical values obtained in bulk crystals, probably as a result of a combination of the optical confinement within the waveguide and possible modification of the charge-transport properties induced by the implantation process.

  15. Lithium-associated hyperthyroidism.

    PubMed

    Siyam, Fadi F; Deshmukh, Sanaa; Garcia-Touza, Mariana

    2013-08-01

    Goiters and hypothyroidism are well-known patient complications of the use of lithium for treatment of bipolar disease. However, the occurrence of lithium-induced hyperthyroidism is a more rare event. Many times, the condition can be confused with a flare of mania. Monitoring through serial biochemical measurement of thyroid function is critical in patients taking lithium. Hyperthyroidism induced by lithium is a condition that generally can be controlled medically without the patient having to discontinue lithium therapy, although in some circumstances, discontinuation of lithium therapy may be indicated. We report on a patient case of lithium-associated hyperthyroidism that resolved after discontinuation of the medication.

  16. Waveguide-mode sensors with sculptured porous waveguide

    NASA Astrophysics Data System (ADS)

    Suzuki, Motofumi; Takagaki, Munehito; Kuriyama, Shohei; Nakajima, Kaoru; Kimura, Kenji

    2013-09-01

    We have investigated feasibility of waveguide-mode sensors, which is sensitized by a nanocolumnar SiO2 waveguide layer deposited by an oblique angle deposition technique. Because the effective refractive index of nanocolumns and fluid composites (n1) depends on that of fluid (n2), sensitivity of the waveguide-mode sensors is expected to be improved. In fact, the resonant angle of incidence of the waveguide-mode sensors, which have various combinations of layer thicknesses, changes significantly depending on the analytes of air (n2 = 1.00), H2O (n2 = 1.33) and C2H5OH (n2 = 1.36). The effective refractive indices of the waveguide layer immersed in these fluid are estimated at 1.28 for air, 1.41 for H2O and 1.42 for C2H5OH. The effective refractive index of the waveguide layer is understood by Bruggeman's effective medium model. Therefore, the nanocolumnar waveguide layer is quite useful to improve sensitivity of the waveguide-mode sensors. In order to improve sensing sensitivity, more porous layer is desirable.

  17. Validity Using Pump-Probe Pulses to Determine the Optical Response of Niobate Crystals

    NASA Technical Reports Server (NTRS)

    Liu, Huimin; Jia, Weiyi

    1997-01-01

    A variety of niobate crystals have found their places in nonlinear optical applications as well as in laser devices. In recent years much attention has been paid to study the ultrafast optical response in a variety of photorefractive crystals such as KTa(1-x)Nb(x)O3 and KNbO3 crystals, glasses, semiconductors and polymers for applications in optical switching, information processing, optical computing, and all-optical device systems. Third-order optical nonlinearity is the most important property for realization of all-optical switching. Therefore experiments have been performed on the third order susceptibility using a variety of techniques such as the third-order harmonic generation, EFISH and degenerate four-wave mixing(DFWM). The latter has been conducted with a variety of pump wavelengths and with nanosecond, picosecond and femtosecond pulses. Niobate crystals, such as potassium niobate KNbO3, potassium tantalate niobate KTN family (KTa(1-x)Nb(x)O3), strontium barium niobate SBN (Sr(x)Ba(1-x)Nb2O6) and potassium-sodium niobate SBN (KNSBN) are attractive due to their photorefractive properties for application in optical storage and processing. The pulsed probe experiments performed on theses materials have suggested two types of time responses. These responses have been associated with an coherent response due to Chi(sup 3), and a long lived component due to excited state population. Recent study of DFWM on KNbO3 and KTN family reveals that the long lived component of those crystals depends on the crystal orientation. A slowly decaying signal is observable when the grating vector K(sub g) is not perpendicular to the C-axis of those photorefractive crystals', otherwise the optical response signal would be only a narrow coherent peak with FWHM equal to the cross-correlation width of the write beam pulses. Based on this understanding, we study the photodynamical process of a variety of niobate crystals using DFWM in a Kg perpindicular to C geometry with a ps

  18. Hollow waveguide cavity ringdown spectroscopy

    NASA Technical Reports Server (NTRS)

    Dreyer, Chris (Inventor); Mungas, Greg S. (Inventor)

    2012-01-01

    Laser light is confined in a hollow waveguide between two highly reflective mirrors. This waveguide cavity is used to conduct Cavity Ringdown Absorption Spectroscopy of loss mechanisms in the cavity including absorption or scattering by gases, liquid, solids, and/or optical elements.

  19. Neutron resonances in planar waveguides

    SciTech Connect

    Kozhevnikov, S. V. E-mail: kzh-sv@mail.ru; Ignatovich, V. K.; Petrenko, A. V.; Radu, F.

    2016-12-15

    We report on the results of the experimental investigation of the spectral width of neutron resonances in planar waveguides using the time-of-flight method and recording the microbeam emerging from the waveguide end. Experimental data are compared with the results of theoretical calculations.

  20. Silicon-tin oxynitride glassy composition and use as anode for lithium-ion battery

    DOEpatents

    Neudecker, Bernd J.; Bates, John B.

    2001-01-01

    Disclosed are silicon-tin oxynitride glassy compositions which are especially useful in the construction of anode material for thin-film electrochemical devices including rechargeable lithium-ion batteries, electrochromic mirrors, electrochromic windows, and actuators. Additional applications of silicon-tin oxynitride glassy compositions include optical fibers and optical waveguides.

  1. Sintering of Lead-Free Piezoelectric Sodium Potassium Niobate Ceramics

    PubMed Central

    Malič, Barbara; Koruza, Jurij; Hreščak, Jitka; Bernard, Janez; Wang, Ke; Fisher, John G.; Benčan, Andreja

    2015-01-01

    The potassium sodium niobate, K0.5Na0.5NbO3, solid solution (KNN) is considered as one of the most promising, environment-friendly, lead-free candidates to replace highly efficient, lead-based piezoelectrics. Since the first reports of KNN, it has been recognized that obtaining phase-pure materials with a high density and a uniform, fine-grained microstructure is a major challenge. For this reason the present paper reviews the different methods for consolidating KNN ceramics. The difficulties involved in the solid-state synthesis of KNN powder, i.e., obtaining phase purity, the stoichiometry of the perovskite phase, and the chemical homogeneity, are discussed. The solid-state sintering of stoichiometric KNN is characterized by poor densification and an extremely narrow sintering-temperature range, which is close to the solidus temperature. A study of the initial sintering stage revealed that coarsening of the microstructure without densification contributes to a reduction of the driving force for sintering. The influences of the (K + Na)/Nb molar ratio, the presence of a liquid phase, chemical modifications (doping, complex solid solutions) and different atmospheres (i.e., defect chemistry) on the sintering are discussed. Special sintering techniques, such as pressure-assisted sintering and spark-plasma sintering, can be effective methods for enhancing the density of KNN ceramics. The sintering behavior of KNN is compared to that of a representative piezoelectric lead zirconate titanate (PZT). PMID:28793702

  2. Growth and Transverse Field Muon Spin Rotation of Cobalt Niobate

    NASA Astrophysics Data System (ADS)

    Munsie, Timothy; Millington, Anna; Marjerrison, Casey; Medina, Teresa; Wilson, Murray; Kermarrec, Edwin; Liu, Lian; Dabkowska, Hanna; Uemura, Yasutomo; Williams, Travis; Luke, Graeme

    2014-03-01

    Cobalt niobate, CoNb2O6, is a material whose spins, when in a transverse field, act like the theoretical ideal 1D-Ising model. This occurs due to the magnetic spins aligning highly anisotropically along the Co2+ chains. Because of this unique structure and material performance, the creation and characterization of this material is of both experimental and theoretical interest. The research we will present is a detailing of changes in the characteristics of the growth of the material utilizing the optical floating zone crystal growth method compared to previous growth parameters and an examination of this material in a moderately high transverse field using the technique of muon spin rotation (μSR). We have determined that the quality of crystals created by the floating zone are highly dependent on the growth parameters utilized (original ceramic shape and rotation rate) and dictate the speed at which the growth can be performed. Transverse Field μSR shows a gradual but significant change to the magnetic structure of the material below 5 K. Second Affiliation: Brockhouse Institute for Materials Research.

  3. Sintering of Lead-Free Piezoelectric Sodium Potassium Niobate Ceramics.

    PubMed

    Malič, Barbara; Koruza, Jurij; Hreščak, Jitka; Bernard, Janez; Wang, Ke; Fisher, John G; Benčan, Andreja

    2015-12-01

    The potassium sodium niobate, K0.5Na0.5NbO₃, solid solution (KNN) is considered as one of the most promising, environment-friendly, lead-free candidates to replace highly efficient, lead-based piezoelectrics. Since the first reports of KNN, it has been recognized that obtaining phase-pure materials with a high density and a uniform, fine-grained microstructure is a major challenge. For this reason the present paper reviews the different methods for consolidating KNN ceramics. The difficulties involved in the solid-state synthesis of KNN powder, i.e., obtaining phase purity, the stoichiometry of the perovskite phase, and the chemical homogeneity, are discussed. The solid-state sintering of stoichiometric KNN is characterized by poor densification and an extremely narrow sintering-temperature range, which is close to the solidus temperature. A study of the initial sintering stage revealed that coarsening of the microstructure without densification contributes to a reduction of the driving force for sintering. The influences of the (K + Na)/Nb molar ratio, the presence of a liquid phase, chemical modifications (doping, complex solid solutions) and different atmospheres (i.e., defect chemistry) on the sintering are discussed. Special sintering techniques, such as pressure-assisted sintering and spark-plasma sintering, can be effective methods for enhancing the density of KNN ceramics. The sintering behavior of KNN is compared to that of a representative piezoelectric lead zirconate titanate (PZT).

  4. Seismic Waveguide of Metamaterials

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Hoon; Das, Mukunda P.

    We developed a new method of an earthquake-resistant design to support conventional aseismic system using acoustic metamaterials. The device is an attenuator of a seismic wave that reduces the amplitude of the wave exponentially. Constructing a cylindrical shell-type waveguide composed of many Helmholtz resonators that creates a stop-band for the seismic frequency range, we convert the seismic wave into an attenuated one without touching the building that we want to protect. It is a mechanical way to convert the seismic energy into sound and heat.

  5. Microwave variable waveguide attenuator.

    PubMed

    Fabeni, P; Mugnai, D; Pazzi, G P; Ranfagni, A

    2008-06-01

    A new type of cutoff attenuator is presented. The attenuator works in the X-band in conditions of almost perfect matching. This means that the phase of the wave, which propagates inside the guide, does not suffer sensible variation in the passage between X- and K(u)-bands. Moreover, the attenuator works directly in the X-band, avoiding the passage between waveguide and cable, thus eliminating spurious effects due to this (double) passage. Experimental results of attenuation and dephasing using a prototype are also presented.

  6. Athermal silicon subwavelength grating waveguides

    NASA Astrophysics Data System (ADS)

    Ibrahim, M.; Schmid, J. H.; Cheben, P.; Lapointe, J.; Janz, S.; Bock, P. J.; Densmore, A.; Lamontagne, B.; Ma, R.; Xu, D.-X.; Ye, W. N.

    2011-08-01

    In this paper, athermal subwavelength grating (SWG) waveguides are investigated. Both numerical simulations and experimental results show that a temperature independent behaviour can be achieved by combining two materials with opposite thermo-optic coefficients within the waveguide. SU-8 polymer with a negative thermo-optic coefficient (dn/dT = -1.1x10-4 K-1) is used in our silicon SWG waveguides to compensate for silicon's positive thermo-optic coefficient of 1.9x10-4 K-1. The grating duty ratio required to achieve an athermal behavior is reported to vary as a function of the operating wavelength and the waveguide dimensions. For example, for athermal waveguides of 260 nm in height, duty ratios of 61.3% and 83.3% were calculated for TE and TM polarized light respectively for a 450 nm wide waveguide, compared to ratios of 79% and 90% for a 350 nm wide waveguide. It is also reported that with increasing width, and increasing height, a smaller grating duty ratio is necessary to achieve an athermal behaviour. A smaller fraction of silicon would hence be needed to compensate for the polymer's negative thermo-optic effect in the waveguide core. Subwavelength sidewall grating (SWSG) waveguides are also proposed here as alternatives to high duty ratio SWG waveguides that are required for guiding TM polarized light. Assuming a duty ratio of 50%, the width of the narrow segments for temperature-independent behavior is found by numerical simulations to be 125 nm and 143 nm for TE and TM polarized light, respectively.

  7. New, dense, and fast scintillators based on rare-earth tantalo-niobates

    NASA Astrophysics Data System (ADS)

    Voloshyna, O. V.; Boiaryntseva, I. A.; Baumer, V. N.; Ivanov, A. I.; Korjik, M. V.; Sidletskiy, O. Ts.

    2014-11-01

    Samples of undoped yttrium and gadolinium tantalo-niobates with common formulae RE(NbxTa1-x)O4, where RE=Y or Gd and x=0-1, have been obtained by solid-state reaction. Systematic study of structural, luminescent, and scintillation properties of these compounds was carried out. Lattice parameters and space groups of the mixed compounds were identified. UV- and X-ray luminescence spectra, as well as relative light outputs and scintillation decay times are measured. Gadolinium tantalo-niobate with the formulae GdNb0.2Ta0.8O4 showed the light output around 13 times larger than PbWO4 and fast decay with time constant 12 ns without additional slow component. Gadolinium tantalo-niobates may be considered as promising materials for high energy physics due to extremely high density, substantial light output, and fast decay.

  8. Dielectric properties of lead indium niobate ceramics synthesized by conventional solid state reaction method

    SciTech Connect

    Ramesh, G.; Subramanian, V.; Sivasubramanian, V.

    2010-12-15

    Pyrochlore free lead indium niobate ceramics are successfully prepared using wolframite precursor by conventional solid state reaction method in air atmosphere, by adding an excess amount of MgO in PbO-InNbO{sub 4} mixture. The dielectric properties of lead indium niobate ceramic studied as a function of both temperature and frequency indicate relaxor ferroelectric behavior with maximum dielectric constant of 4310 at 40 {sup {omicron}}C for 1 kHz. Lowering of transition temperature and enhancement of dielectric constant at room temperature, compared to earlier reports, may be due to the diffusion of magnesium ion into the lead indium niobate. The saturation polarization P{sub s}, measured at room temperature, is found to be 22.5 {mu}C/cm{sup 2} for 40 kV/cm.

  9. Preparation of porous solids composed of layered niobate walls from colloidal mixtures of niobate nanosheets and polystyrene spheres.

    PubMed

    Miyamoto, Nobuyoshi; Kuroda, Kazuyuki

    2007-09-01

    Macroporous solids with crystalline layered walls were fabricated from colloidal mixtures of size-controlled niobate nanosheets and polystyrene spheres. The macroporous solids, obtained after burning off the spheres, were characterized by scanning electron microscopy and X-ray diffraction. The obtained structures strongly depended on the lateral dimension L of the nanosheets used. When small nanosheets (L=100 nm) were used, partly ordered macroporous solids with interconnected pores were obtained, whereas sponge-like random macroporous structures were obtained with larger nanosheets (L=190 and 270 nm). Peapod-like hollow structures were obtained when we used small (L=190 nm) and very large (L=3 microm) nanosheets at the same time. The microstructure of the pore walls was controllable by changing the calcination conditions. The walls were composed of propylammonium/K(4)Nb(6)O(17) intercalation compound which has a layered structure with exchangeable cations in the interlayer space, stable up to 350 degrees C for 6 h on calcination. The walls were converted to crystalline K(8)Nb(18)O(49) after calcination at 500 degrees C for 6 h.

  10. Molten salt lithium cells

    DOEpatents

    Raistrick, I.D.; Poris, J.; Huggins, R.A.

    1980-07-18

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400 to 500/sup 0/C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell which may be operated at temperatures between about 100 to 170/sup 0/C. The cell is comprised of an electrolyte, which preferably includes lithium nitrate, and a lithium or lithium alloy electrode.

  11. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1983-01-01

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  12. Molten salt lithium cells

    DOEpatents

    Raistrick, Ian D.; Poris, Jaime; Huggins, Robert A.

    1982-02-09

    Lithium-based cells are promising for applications such as electric vehicles and load-leveling for power plants since lithium is very electropositive and light weight. One type of lithium-based cell utilizes a molten salt electrolyte and is operated in the temperature range of about 400.degree.-500.degree. C. Such high temperature operation accelerates corrosion problems and a substantial amount of energy is lost through heat transfer. The present invention provides an electrochemical cell (10) which may be operated at temperatures between about 100.degree.-170.degree. C. Cell (10) comprises an electrolyte (16), which preferably includes lithium nitrate, and a lithium or lithium alloy electrode (12).

  13. Integrated optic waveguide devices

    NASA Technical Reports Server (NTRS)

    Ramer, O. G.

    1980-01-01

    Integrated optic waveguide circuits with a phase bias and modulator on the same chip were designed, fabricated, and tested for use in a fiber-optic rotation sensor (gyro) under development. Single mode fiber-optic pigtails were permanently coupled to the four ports of the chip. The switch format was based on coherent coupling between waveguides formed in Z-cut LiNbO3. The control of the coupling was achieved by electro-optically varying the phase propagation constants of each guide. Fiber-to-chip interfacing required the development of appropriate fixturing and manipulation techniques to achieve the close tolerance needed for high coupling efficiency between a fiber with an approximately 5 micron m core and a channel guide with a roughly 2 micron m by 5 micron m cross section. Switch and chip performance at 0.85 micron m is discussed as well as potential improvements related to insertion loss reduction, switching voltages, and suppression of Li2O out-diffusion.

  14. Dielectric THz waveguides

    NASA Astrophysics Data System (ADS)

    Dupuis, Alexandre

    In this thesis we have explored a wide variety of dielectric waveguides that rely on many different waveguiding mechanisms to guide THz (far-infrared) radiation. We have explored both theoretically and experimentally a large number of waveguide designs with the aim of reducing propagation and bending losses. The different waveguides can be classified into two fundamentally different strategies for reducing the propagation loss: small-core single-mode evanescent-field fibers or large hollow-core multi-mode tubes. Our focus was first set on exploring the small-core evanescent-field fiber strategy for reducing propagation losses. Following initial theoretical work in our group, much effort was spent on the fabrication and measurement of evanescent porous subwavelength diameter plastic fibers, in an attempt to further reduce the propagation losses. The fabrication of such fibers is a challenge and many novel techniques were devised to enable fiber drawing without hole collapse. The first method sealed the holes of an assembly of polymer tubes and lead to fibers of relatively low porosity (˜25% air within the core) due to reduction in hole size during fiber drawing. The second method was a novel sacrificial polymer technique whereby drawing a completely solid fiber prevented any hole collapse and the subsequent dissolution of the sacrificial polymer revealed the holes in the fiber. The third method was a combination of preform casting using glass molds and drawing with pressurized air within the holes. This led to fibers of record porosity (86% air). The measurement of these porous fibers began with a collaboration with a group from the university of Sherbrooke. At the time, the only available detector was a frequency integrating liquid-helium-cooled bolometer (powermeter). A novel directional coupler method for measuring the losses of subwavelength fibers was developed whereby an evanescent coupler is formed by bringing a probe fiber in proximity to the sample fiber

  15. Resolution of a Prism Waveguide Spectrum Analyzer

    NASA Astrophysics Data System (ADS)

    Shul‧ga, A. V.

    2013-11-01

    We have studied the resolution of a waveguide spectrum analyzer, based on a prism coupler for mode excitation, as a function of the structural parameters of the waveguide. We show that the limiting resolution of the waveguide spectrum analyzer is determined by the ratio of the chromatic dispersion of the waveguide to the imaginary part of the propagation constant for the leaky mode of the waveguide/coupling prism structure.

  16. Electro-optic materials by solid source MOCVD

    SciTech Connect

    Hiskes, R.; Dicarolis, S.A.; Fouquet, J.; Lu, Z.; Feigelson, R.S.; Route, R.K.; Leplingard, F.; Foster, C.M.

    1993-12-01

    The solid source MOCVD technique, employing a single powder vaporization source composed of mixed beta-diketonate metalorganic compounds, has been used to grow thin films of a variety of electro-optic materials, including lithium niobate, strontium barium niobate, and potassium niobate. Preliminary results for potassium niobate films indicate that a volatile potassium organometallic source can be synthesized useful for growing potassium niobate by MOCVD. High single phase (001) oriented strontium barium niobate films have been deposited which exhibit waveguiding behavior. The most extensive work has been done on lithium niobate deposited epitaxially on a variety of substrates. Oriented z-axis (001) films have been grown on c-axis sapphire with and without a (111) oriented platinum base electrode and on a bulk grown lithium niobate substrate. Films grown directly on c-axis sapphire at 700 C exhibit x-ray rocking curve linewidths as low as .044 degrees, nearly perfect in-plane orientation as determined by x-ray phi scans, and peak-to-peak surface roughness less than 40 {Angstrom}. Optical waveguiding has been demonstrated by single prism coupling technique on similar films 1175--2000 {Angstrom} thick grown at 500 C, with optical losses of approximately 2 db/cm at 632.8 nm measured over 3.5 cm long films. Polarization vs. electric field measurements on 1100 {Angstrom} thick films grown on platinum show a hysteresis loop indicating ferroelectric behavior.

  17. Configurable silicon photonic crystal waveguides

    SciTech Connect

    Prorok, Stefan; Petrov, Alexander; Eich, Manfred; Luo, Jingdong; Jen, Alex K.-Y.

    2013-12-23

    In this Letter, we demonstrate that the mode cut off of a photonic crystal waveguide can be trimmed with high accuracy by electron beam bleaching of a chromophore doped polymer cladding. Using this method, configurable waveguides are realized, which allow for spatially resolved changes of the photonic crystal's effective lattice constant as small as 7.6 pm. We show three different examples how to take advantage of configurable photonic crystal waveguides: Shifting of the complete transmission spectrum, definition of cavities with high quality factor, and tuning of existing cavities.

  18. Scintillator Waveguide For Sensing Radiation

    DOEpatents

    Bliss, Mary; Craig, Richard A.; Reeder; Paul L.

    2003-04-22

    The present invention is an apparatus for detecting ionizing radiation, having: a waveguide having a first end and a second end, the waveguide formed of a scintillator material wherein the therapeutic ionizing radiation isotropically generates scintillation light signals within the waveguide. This apparatus provides a measure of radiation dose. The apparatus may be modified to permit making a measure of location of radiation dose. Specifically, the scintillation material is segmented into a plurality of segments; and a connecting cable for each of the plurality of segments is used for conducting scintillation signals to a scintillation detector.

  19. Strontium barium niobate single crystals, growth and ferroelectric properties

    NASA Astrophysics Data System (ADS)

    Lukasiewicz, T.; Swirkowicz, M. A.; Dec, J.; Hofman, W.; Szyrski, W.

    2008-04-01

    Single crystals of strontium-barium niobate Sr xBa 1-xNb 2O 6 (SBN) undoped and doped with Ce or Cr were grown by the Czochralski method. The inductive heating system was used. In order to improve conditions of growth, a crucible-base cooling was introduced. Single crystals of the following nominal compositions have been obtained: Sr 0.4Ba 0.6Nb 2O 6, Sr 0.5Ba 0.5Nb 2O 6, Sr 0.61Ba 0.39Nb 2O 6 (congruent melting) and Sr 0.75Ba 0.25Nb 2O 6, designated hereafter as SBN40, SBN50, SBN61 and SBN75. They were up to 22 mm in diameter and 40 mm in length with characteristic 24 faces, free from striations and other extended defects. All the crystals were grown in the [0 0 1] direction. The dopants (Ce or Cr) were added to the SBN61 composition. By use of ICP-OES method, the chemical compositions were checked. Etch pit density was also measured. In the case of the undoped single crystals, it was found to be 2.4×10 2-5.6×10 3 cm -2 but in the case of Ce or Cr doping, it increased up to 3.6×10 4-1.8×10 5 cm -2. Investigations of the linear dielectric response measured within 10 0⩽ f⩽10 5 Hz along the polar c-axis of four obtained single-crystalline SBN compounds revealed a gradual crossover from conventional ferroelectric (SBN40) to extreme relaxor (SBN75) behavior.

  20. Lightning arrestor connector lead magnesium niobate qualification pellet test procedures.

    SciTech Connect

    Tuohig, W.; Mahoney, Patrick A.; Tuttle, Bruce Andrew; Wheeler, Jill Susanne

    2009-02-01

    Enhanced knowledge preservation for DOE DP technical component activities has recently received much attention. As part of this recent knowledge preservation effort, improved documentation of the sample preparation and electrical testing procedures for lead magnesium niobate--lead titanate (PMN/PT) qualification pellets was completed. The qualification pellets are fabricated from the same parent powders used to produce PMN/PT lightning arrestor connector (LAC) granules at HWF&T. In our report, the procedures for fired pellet surface preparation, electrode deposition, electrical testing and data recording are described. The dielectric measurements described in our report are an information only test. Technical reasons for selecting the electrode material, electrode size and geometry are presented. The electrical testing is based on measuring the dielectric constant and dissipation factor of the pellet during cooling from 280 C to 220 C. The most important data are the temperature for which the peak dielectric constant occurs (Curie Point temperature) and the peak dielectric constant magnitude. We determined that the peak dielectric constant for our procedure would be that measured at 1 kHz at the Curie Point. Both the peak dielectric constant and the Curie point parameters provide semi-quantitative information concerning the chemical and microstructural homogeneity of the parent material used for the production of PMN/PT granules for LACs. Finally, we have proposed flag limits for the dielectric data for the pellets. Specifically, if the temperature of the peak dielectric constant falls outside the range of 250 C {+-} 30 C we propose that a flag limit be imposed that will initiate communication between production agency and design agency personnel. If the peak dielectric constant measured falls outside the range 25,000 {+-} 10,000 we also propose that a flag limit be imposed.