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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. 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

  6. 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

  7. Demonstration of ultraprecision ductile-mode cutting for lithium niobate microring waveguides

    NASA Astrophysics Data System (ADS)

    Takigawa, Ryo; Higurashi, Eiji; Kawanishi, Tetsuya; Asano, Tanemasa

    2016-11-01

    In this paper, the application of the ultraprecision ductile-mode cutting method to the fabrication of microring waveguides in lithium niobate crystal was investigated. Although it was difficult to apply a mechanical cutting method to the fabrication of microring waveguides with smooth sidewalls, it was confirmed that no harmful cutting traces on the machined surface occur with the appropriate movement of the cutting tool. The root-mean-square surface roughness of the resulting sidewall was 6.1 nm, which is sufficiently small to suppress the scattering loss of the circulating light. In addition, the conditions for the ductile-mode cutting of lithium niobate crystal were investigated.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  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. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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).

  1. 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

  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. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  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. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  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. Laser scattering induced holograms in lithium niobate. [observation of diffraction cones

    NASA Technical Reports Server (NTRS)

    Magnusson, R.; Gaylord, T. K.

    1974-01-01

    A 3.0-mm thick poled single crystal of lithium niobate doped with 0.1 mole% iron was exposed to a single beam and then to two intersecting beams of an argon ion laser operating at 515-nm wavelength. Laser scattering induced holograms were thus written and analyzed. The presence of diffraction cones was observed and is shown to result from the internally recorded interference pattern resulting from the interference of the original incident laser beam with light scattered from material inhomogeneities. This phenomenon is analyzed using Ewald sphere construction techniques which reveal the geometrical relationships existing for the diffraction cones.

  6. 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.

  7. 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.

  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. 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.}

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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}

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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%.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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+).

  16. 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).

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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%.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  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. 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.

  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. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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}

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Lithium

    MedlinePlus

    ... bipolar disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Lithium ... Lithium is also sometimes used to treat depression, schizophrenia (a mental ... emotions), disorders of impulse control (inability to resist the urge ...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Chemically prepared lead magnesium niobate dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-11-01

    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.

  20. 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.)

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. Waveguide cooling system

    NASA Astrophysics Data System (ADS)

    Chen, B. C. J.; Hartop, R. W.

    1981-04-01

    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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. [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.

  7. 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 ...

  8. 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.

  9. 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.

  10. Omnidirectional optical waveguide

    DOEpatents

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  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. 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.

  19. [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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  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. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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).

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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).

  19. 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.

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. Lithium Battery Diaper Ulceration.

    PubMed

    Maridet, Claire; Taïeb, Alain

    2016-01-01

    We report a case of lithium battery diaper ulceration in a 16-month-old girl. Gastrointestinal and ear, nose, and throat lesions after lithium battery ingestion have been reported, but skin involvement has not been reported to our knowledge.

  5. Giant piezoelectricity in potassium-sodium niobate lead-free ceramics.

    PubMed

    Wang, Xiaopeng; Wu, Jiagang; Xiao, Dingquan; Zhu, Jianguo; Cheng, Xiaojing; Zheng, Ting; Zhang, Binyu; Lou, Xiaojie; Wang, Xiangjian

    2014-02-19

    Environment protection and human health concern is the driving force to eliminate the lead from commercial piezoelectric materials. In 2004, Saito et al. [ Saito et al., Nature , 2004 , 432 , 84 . ] developed an alkali niobate-based perovskite solid solution with a peak piezoelectric constant d33 of 416 pC/N when prepared in the textured polycrystalline form, intriguing the enthusiasm of developing high-performance lead-free piezoceramics. Although much attention has been paid on the alkali niobate-based system in the past ten years, no significant breakthrough in its d33 has yet been attained. Here, we report an alkali niobate-based lead-free piezoceramic with the largest d33 of ∼490 pC/N ever reported so far using conventional solid-state method. In addition, this material system also exhibits excellent integrated performance with d33∼390-490 pC/N and TC∼217-304 °C by optimizing the compositions. This giant d33 of the alkali niobate-based lead-free piezoceramics is ascribed to not only the construction of a new rhombohedral-tetragonal phase boundary but also enhanced dielectric and ferroelectric properties. Our finding may pave the way for "lead-free at last".

  6. Etude par spectroscopie vibrationnelle des niobates de sodium et d'argent de structure perovskite

    NASA Astrophysics Data System (ADS)

    Husson, E.; Repelin, Y.

    Infrared and Raman spectra of the niobates NaNbO 3 and AgNbO 3 of perovskite structure are analysed. An assignment of the frequencies is proposed. The influence of the antiferroelectric direction upon the NbO bonds is shown, as the influence of the A cation upon the AO and NbO bonds.

  7. Safe disposal of radioactive iodide ions from solutions by Ag2O grafted sodium niobate nanofibers.

    PubMed

    Mu, Wanjun; Li, Xingliang; Liu, Guoping; Yu, Qianhong; Xie, Xiang; Wei, Hongyuan; Jian, Yuan

    2016-01-14

    Radioactive iodine isotopes are released into the environment by the nuclear industry and medical research institutions using radioactive materials, and have negative effects on organisms living within the ecosystem. Thus, safe disposal of radioactive iodine is necessary and crucial. For this reason, the uptake of iodide ions was investigated in Ag2O nanocrystal grafted sodium niobate nanofibers, which were prepared by forming a well-matched phase coherent interface between them. The resulting composite was applied as an efficient adsorbent for I(-) anions by forming an AgI precipitate, which also remained firmly attached to the substrates. Due to their one-dimensional morphology, the new adsorbents can be easily dispersed in liquids and readily separated after purification. This significantly enhances the adsorption efficiency and reduces the separation costs. The change in structure from the pristine sodium niobate to Ag2O anchored sodium niobate and to the used adsorbent was examined by using various characterization techniques. The effects of Ag(+) concentration, pH, equilibration time, ionic strength and competing ions on the iodide ion removal ability of the composite were studied. The Ag2O nanocrystal grafted sodium niobate adsorbent showed a high adsorption capacity and excellent selectivity for I(-) anions in basic solutions. Our results are useful for the further development of improved adsorbents for removing I(-) anions from basic wastewater.

  8. Hydrothermal method of synthesis of rare-earth tantalates and niobates

    DOEpatents

    Nyman, May D; Rohwer, Lauren E.S.; Martin, James E

    2012-10-16

    A hydrothermal method of synthesis of a family of rare-earth Group 5 oxides, where the Group 5 oxide is a niobate or tantalate. The rare-earth Group 5 oxides can be doped with suitable emitter ions to form nanophosphors.

  9. 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.

  10. 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

  11. Lithium Cell Reactions.

    DTIC Science & Technology

    1985-02-01

    Page 1. INVESTIGATION OF CHEMICAL, ELECTROCHEMICAL AND PARASITIC REACTIONS IN LITHIUM - THIONYL CHLORIDE CELLS ....... ................. 1 1.1 INTRODUCTION...OF LITHIUM - THIONYL CHLORIDE CELLS. ................ 56 1.4.1 Carbon Limited Overdischarge...............56 1.4.1.1 Background... LITHIUM THIONYL - CHLORIDE CELLS. .. ............ ...... 101 1.5.1 Background. ....... ............ .... 101 1.5.2 Microphotography

  12. Lithium Cell Reactions.

    DTIC Science & Technology

    1983-12-01

    SUPPLEMENTARY NOTES It. KEY WORDS (Continue on reverse .,ide if necessary and Identify by block number) Batteries Thionyl Chloride Batteries Lithium ...Batteries Lithium Cells Primary Batteries Thionyl Chloride Cells Non Rechargeable Batteries Electrochemical Reactions 20. ABSTRACT (Continue on reverse...INVESTIGATION OF CHEMICAL, ELECTROCHEMICAL AND PARASITIC REACTIONS IN LITHIUM - THIONYL CHLORIDE CELLS .......................................... 1 1.0 IN TRO D UC

  13. Defect Chemistry and Microstructure of Complex Perovskite Barium Zinc Niobate

    NASA Astrophysics Data System (ADS)

    Peng, Ping

    1991-02-01

    This dissertation presents a systematic study of the characterization of the phase transitions, microstructures, defects and transport properties of undoped and doped complex perovskite barium zinc niobate (BZN). Complex perovskite BZN is a paraelectric material while its parent material barium titanate is ferroelectric. With codoping of (Zn + 2Nb) into Ti site, BaTiO_3 shows three distinguished features. First, the Curie temperature is lowered; second, the three phase transitions (cubic-tetragonal-orthorhombic-rhombohedral) coalesce; and lastly, the transition becomes diffuse showing a typical 2nd order phase transition compared with 1st order in undoped BaTiO_3. Complex microchemical ordering is another characteristic of BZN. Stoichiometric BZN shows a mixture of two types of ordering schemes. 1:1, 1:2 ordered microdomains and the disordered matrix co-exist. The 1:1 type ordering involves an internal charge imbalance which inhibits the growth of 1:1 type of ordered microdomains. The 1:2 type ordering is consistent with the chemical composition of BZN. These ordering patterns can be modified by either adjustment of the Zn/Nb ratio or by doping. The defect structure of the stoichiometric BZN is closely related to that of BaTiO_3. Stoichiometric BZN is an insulator with wide band gap (~ 3.70 eV). Undoped BZN has a high oxygen vacancy concentration which comes from three possible sources, such as unavoidable acceptor impurities, due to their natural abundance, Zn/Nb ratio uncertainty due to processing limitations, and high temperature ZnO loss due to sintering process. The oxygen vacancy concentration for undoped BZN lays in the neighborhood of 1500 ppm (atm.). The compensation defects for various dopants have also been identified. Both electrons and holes conduct by a small polaron mechanism. Various thermodynamic parameters, such as enthalpies of oxidation and reduction, mass action constants for intrinsic electronic disorder, oxidation and reduction have been

  14. 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.

  15. Configurable silicon photonic crystal waveguides

    NASA Astrophysics Data System (ADS)

    Prorok, Stefan; Petrov, Alexander; Eich, Manfred; Luo, Jingdong; Jen, Alex K.-Y.

    2013-12-01

    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.

  16. 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.

  17. Optical Interferometers for Sensing Electromagnetic Fields

    DTIC Science & Technology

    1991-03-29

    with 1000A of Ti at 1025 C for 8 hours. The crystal surface is subsequently etched in HF:HNO, at 80 to 90 C for 3 minutes 29 Figure 8. +Z oriented... semiconductors , dielectrics, such as potassium titanyl phosphate (KTP) and ferroelectrics, such as lithium niobate and lithium tantalate. Optical... surface of the substrate material. The waveguide is bounded only in one direction by the thickness of the waveguide layer. The optical beam is

  18. Lithium use in batteries

    USGS Publications Warehouse

    Goonan, Thomas G.

    2012-01-01

    Lithium has a number of uses but one of the most valuable is as a component of high energy-density rechargeable lithium-ion batteries. Because of concerns over carbon dioxide footprint and increasing hydrocarbon fuel cost (reduced supply), lithium may become even more important in large batteries for powering all-electric and hybrid vehicles. It would take 1.4 to 3.0 kilograms of lithium equivalent (7.5 to 16.0 kilograms of lithium carbonate) to support a 40-mile trip in an electric vehicle before requiring recharge. This could create a large demand for lithium. Estimates of future lithium demand vary, based on numerous variables. Some of those variables include the potential for recycling, widespread public acceptance of electric vehicles, or the possibility of incentives for converting to lithium-ion-powered engines. Increased electric usage could cause electricity prices to increase. Because of reduced demand, hydrocarbon fuel prices would likely decrease, making hydrocarbon fuel more desirable. In 2009, 13 percent of worldwide lithium reserves, expressed in terms of contained lithium, were reported to be within hard rock mineral deposits, and 87 percent, within brine deposits. Most of the lithium recovered from brine came from Chile, with smaller amounts from China, Argentina, and the United States. Chile also has lithium mineral reserves, as does Australia. Another source of lithium is from recycled batteries. When lithium-ion batteries begin to power vehicles, it is expected that battery recycling rates will increase because vehicle battery recycling systems can be used to produce new lithium-ion batteries.

  19. Complete power concentration into a single waveguide in large-scale waveguide array lenses

    PubMed Central

    Catrysse, Peter B.; Liu, Victor; Fan, Shanhui

    2014-01-01

    Waveguide array lenses are waveguide arrays that focus light incident on all waveguides at the input side into a small number of waveguides at the output side. Ideal waveguide array lenses provide complete (100%) power concentration of incident light into a single waveguide. While of great interest for several applications, ideal waveguide array lenses have not been demonstrated for practical arrays with large numbers of waveguides. The only waveguide arrays that have sufficient degrees of freedom to allow for the design of an ideal waveguide array lens are those where both the propagation constants of the individual waveguides and the coupling constants between the waveguides vary as a function of space. Here, we use state-of-the-art numerical methods to demonstrate complete power transfer into a single waveguide for waveguide array lenses with large numbers of waveguides. We verify this capability for more than a thousand waveguides using a spatial coupled mode theory. We hereby extend the state-of-art by more than two orders of magnitude. We also demonstrate for the first time a physical design for an ideal waveguide array lens. The design is based on an aperiodic metallic waveguide array and focuses ~100% of the incident light into a deep-subwavelength focal spot. PMID:25319203

  20. Coplanar waveguide supercomponents

    NASA Astrophysics Data System (ADS)

    Yeo, Mike

    The application of coplanar-waveguide (CPWG) technology to develop rugged compact high-performance electronic components for use in military receivers and similar equipment is described and illustrated with diagrams and photographs of typical CPWG implementations. The operating principles and characteristics of CPWGs are reviewed; the advantages and limitations of stripline, microstrip, and CPWG technologies are listed in a table and compared; and the inherently good isolation, the ease of making series and shunt connections, and the flexibility of ground-plane spacing of CPWGs are emphasized. The CPWG-based components shown include a Ku-band dual downconverter with 17 different functional circuits, an antenna switching unit with switches, driver, couplers, and ferrite devices; and two mixed-media multifunction hybrid components.

  1. Whispering-mode waveguide

    NASA Astrophysics Data System (ADS)

    Kurnit, N. A.

    Properties of a relatively new type of waveguide structure of potential use of confining infrared radiation to a small mode volume over long path lengths are reviewed. A single guiding surface with curvature radius rho and band radius R allows propagation of a near-grazing incidence whispering mode of transverse width approximately (lambda square root of rho R/pi) sup 1/2 and radial width approximately 1/2 (sq lambda R)/sup 1/3. For sufficiently large rho, the loss per revolution for TE mode propagation is approximately pi A/sub N/, where A/sub N/ is the normal-incidence reflection loss. Results on a number of prototype structures in general agreement with these considerations are described.

  2. Nonlinear Waves in Waveguides

    NASA Astrophysics Data System (ADS)

    Leble, Sergei B.

    S.B. Leble's book deals with nonlinear waves and their propagation in metallic and dielectric waveguides and media with stratification. The underlying nonlinear evolution equations (NEEs) are derived giving also their solutions for specific situations. The reader will find new elements to the traditional approach. Various dispersion and relaxation laws for different guides are considered as well as the explicit form of projection operators, NEEs, quasi-solitons and of Darboux transforms. Special points relate to: 1. the development of a universal asymptotic method of deriving NEEs for guide propagation; 2. applications to the cases of stratified liquids, gases, solids and plasmas with various nonlinearities and dispersion laws; 3. connections between the basic problem and soliton- like solutions of the corresponding NEEs; 4. discussion of details of simple solutions in higher- order nonsingular perturbation theory.

  3. Waveguides for performing enzymatic reactions

    DOEpatents

    Levene; Michael J. , Korlach; Jonas , Turner; Stephen W. , Craighead; Harold G. , Webb; Watt W.

    2007-11-06

    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 wave guide, 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.

  4. Temporal waveguides for optical pulses

    SciTech Connect

    Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

    2016-05-12

    Here we discuss, temporal total internal reflection (TIR), in analogy to the conventional TIR of an optical beam at a dielectric interface, is the total reflection of an optical pulse inside a dispersive medium at a temporal boundary across which the refractive index changes. A pair of such boundaries separated in time acts as the temporal analog of planar dielectric waveguides. We study the propagation of optical pulses inside such temporal waveguides, both analytically and numerically, and show that the waveguide supports a finite number of temporal modes. We also discuss how a single-mode temporal waveguide can be created in practice. In contrast with the spatial case, the confinement can occur even when the central region has a lower refractive index.

  5. Temporal waveguides for optical pulses

    DOE PAGES

    Plansinis, Brent W.; Donaldson, William R.; Agrawal, Govind P.

    2016-05-12

    Here we discuss, temporal total internal reflection (TIR), in analogy to the conventional TIR of an optical beam at a dielectric interface, is the total reflection of an optical pulse inside a dispersive medium at a temporal boundary across which the refractive index changes. A pair of such boundaries separated in time acts as the temporal analog of planar dielectric waveguides. We study the propagation of optical pulses inside such temporal waveguides, both analytically and numerically, and show that the waveguide supports a finite number of temporal modes. We also discuss how a single-mode temporal waveguide can be created inmore » practice. In contrast with the spatial case, the confinement can occur even when the central region has a lower refractive index.« less

  6. Multiscaffold DNA Origami Nanoparticle Waveguides

    PubMed Central

    2013-01-01

    DNA origami templated self-assembly has shown its potential in creating rationally designed nanophotonic devices in a parallel and repeatable manner. In this investigation, we employ a multiscaffold DNA origami approach to fabricate linear waveguides of 10 nm diameter gold nanoparticles. This approach provides independent control over nanoparticle separation and spatial arrangement. The waveguides were characterized using atomic force microscopy and far-field polarization spectroscopy. This work provides a path toward large-scale plasmonic circuitry. PMID:23841957

  7. Optical Waveguide Scattering Reduction. II.

    DTIC Science & Technology

    1980-12-01

    FAD-AOAR 815 BATTELLEWCOLUMBUS LABS ON F/S 20/6 OPTICAL WAVEGUIDE SCATTER ING REDUC TION. II.(U) 7 DEC 80 0 W VAHEY, N F HARTMAN, R C SHERMAN F3361... OPTICAL WAVEGUIDE SCATTERING REDUCTION II M BATTELLE COLUMBUS LABORATORIES 505 KING AVENUE COLUMBUS, OHIO 43201 DTIC ELECTEf MAY 12 198111 December...reviewed and is approved for publication. DOUGLAS AWIWILLE, Project Engineer KENNETH R. HUTCHINSON, Chief Electro- Optics Techniques and Electro- Optics

  8. MHD waveguides in space plasma

    SciTech Connect

    Mazur, N. G.; Fedorov, E. N.; Pilipenko, V. A.

    2010-07-15

    The waveguide properties of two characteristic formations in the Earth's magnetotail-the plasma sheet and the current (neutral) sheet-are considered. The question of how the domains of existence of different types of MHD waveguide modes (fast and slow, body and surface) in the (k, {omega}) plane and their dispersion properties depend on the waveguide parameters is studied. Investigation of the dispersion relation in a number of particular (limiting) cases makes it possible to obtain a fairly complete qualitative pattern of all the branches of the dispersion curve. Accounting for the finite size of perturbations across the wave propagation direction reveals new additional effects such as a change in the critical waveguide frequencies, the excitation of longitudinal current at the boundaries of the sheets, and a change in the symmetry of the fundamental mode. Knowledge of the waveguide properties of the plasma and current sheets can explain the occurrence of preferred frequencies in the low-frequency fluctuation spectra in the magnetotail. In satellite observations, the type of waveguide mode can be determined from the spectral properties, as well as from the phase relationships between plasma oscillations and magnetic field oscillations that are presented in this paper.

  9. The synergetic effect of lithium polysulfide and lithium nitrate to prevent lithium dendrite growth

    NASA Astrophysics Data System (ADS)

    Li, Weiyang; Yao, Hongbin; Yan, Kai; Zheng, Guangyuan; Liang, Zheng; Chiang, Yet-Ming; Cui, Yi

    2015-06-01

    Lithium metal has shown great promise as an anode material for high-energy storage systems, owing to its high theoretical specific capacity and low negative electrochemical potential. Unfortunately, uncontrolled dendritic and mossy lithium growth, as well as electrolyte decomposition inherent in lithium metal-based batteries, cause safety issues and low Coulombic efficiency. Here we demonstrate that the growth of lithium dendrites can be suppressed by exploiting the reaction between lithium and lithium polysulfide, which has long been considered as a critical flaw in lithium-sulfur batteries. We show that a stable and uniform solid electrolyte interphase layer is formed due to a synergetic effect of both lithium polysulfide and lithium nitrate as additives in ether-based electrolyte, preventing dendrite growth and minimizing electrolyte decomposition. Our findings allow for re-evaluation of the reactions regarding lithium polysulfide, lithium nitrate and lithium metal, and provide insights into solving the problems associated with lithium metal anodes.

  10. Biocompatible silk step-index optical waveguides

    PubMed Central

    Applegate, Matthew B.; Perotto, Giovanni; Kaplan, David L.; Omenetto, Fiorenzo G.

    2015-01-01

    Biocompatible optical waveguides were constructed entirely of silk fibroin. A silk film (n=1.54) was encapsulated within a silk hydrogel (n=1.34) to form a robust and biocompatible waveguide. Such waveguides were made using only biologically and environmentally friendly materials without the use of harsh solvents. Light was coupled into the silk waveguides by direct incorporation of a glass optical fiber. These waveguides are extremely flexible, and strong enough to survive handling and manipulation. Cutback measurements showed propagation losses of approximately 2 dB/cm. The silk waveguides were found to be capable of guiding light through biological tissue. PMID:26600988

  11. Waveguide harmonic damper for klystron amplifier.

    SciTech Connect

    Kang, Y.

    1998-10-27

    A waveguide harmonic damper was designed for removing the harmonic frequency power from the klystron amplifiers of the APS linac. Straight coaxial probe antennas are used in a rectangular waveguide to form a damper. A linear array of the probe antennas is used on a narrow wall of the rectangular waveguide for damping klystron harmonics while decoupling the fundamental frequency in dominent TE{sub 01} mode. The klystron harmonics can exist in the waveguide as waveguide higher-order modes above cutoff. Computer simulations are made to investigate the waveguide harmonic damping characteristics of the damper.

  12. Method of recycling lithium borate to lithium borohydride through diborane

    DOEpatents

    Filby, Evan E.

    1976-01-01

    This invention provides a method for the recycling of lithium borate to lithium borohydride which can be reacted with water to generate hydrogen for utilization as a fuel. The lithium borate by-product of the hydrogen generation reaction is reacted with hydrogen chloride and water to produce boric acid and lithium chloride. The boric acid and lithium chloride are converted to lithium borohydride through a diborane intermediate to complete the recycle scheme.

  13. Simplified flangeless unisex waveguide coupler assembly

    DOEpatents

    Michelangelo, Dimartino; Moeller, Charles P.

    1993-01-01

    A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150.degree. C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

  14. Simplified flangeless unisex waveguide coupler assembly

    DOEpatents

    Michelangelo, D.; Moeller, C.P.

    1993-05-04

    A unisex coupler assembly is disclosed capable of providing a leak tight coupling for waveguides with axial alignment of the waveguides and rotational capability. The sealing means of the coupler assembly are not exposed to RF energy, and the coupler assembly does not require the provision of external flanges on the waveguides. In a preferred embodiment, O ring seals are not used and the coupler assembly is, therefore, bakeable at a temperature up to about 150 C. The coupler assembly comprises a split collar which clamps around the waveguides and a second collar which fastens to the split collar. The split collar contains an inner annular groove. Each of the waveguides is provided with an external annular groove which receives a retaining ring. The split collar is clamped around one of the waveguides with the inner annular groove of the split collar engaging the retaining ring carried in the external annular groove in the waveguide. The second collar is then slipped over the second waveguide behind the annular groove and retaining ring therein and the second collar is coaxially secured by fastening means to the split collar to draw the respective waveguides together by coaxial force exerted by the second collar against the retaining ring on the second waveguide. A sealing ring is placed against an external sealing surface at a reduced external diameter end formed on one waveguide to sealingly engage a corresponding sealing surface on the other waveguide as the waveguides are urged toward each other.

  15. Integration of a waveguide self-electrooptic effect device and a vertically coupled interconnect waveguide

    DOEpatents

    Vawter, G. Allen

    2008-02-26

    A self-electrooptic effect device ("SEED") is integrated with waveguide interconnects through the use of vertical directional couplers. Light initially propagating in the interconnect waveguide is vertically coupled to the active waveguide layer of the SEED and, if the SEED is in the transparent state, the light is coupled back to the interconnect waveguide.

  16. Investigation of the femtosecond optical limiting properties of monoclinic copper niobate

    NASA Astrophysics Data System (ADS)

    Priyadarshani, N.; Venugopal Rao, S.; Sabari Girisun, T. C.

    2016-10-01

    Investigation of the third-order nonlinear optical properties and optical limiting behaviour of microstructured monoclinic phase copper niobate (CuNb2O6) was performed by the Z-scan technique using femtosecond laser pulses (800 nm, 150 fs, 80 MHz). CuNb2O6 was synthesized by solid-state reaction at a sintering temperature of 700 °C maintained at different times of 3, 6, 9 and 12 h. Formation of rods at higher reaction time of 12 h was observed and is attributed to the mass transport and coalescence processes. From the absorption tail of UV-Vis spectrum, the optical band gap was estimated to be 3.5 eV. In the fluorescence spectra, blue emission was observed near 430 nm and was assigned to the charge transfer from oxygen to central niobium of Nb-O6 octahedra. Open-aperture Z-scan data demonstrated the presence of nonlinear absorption in copper niobate and are ascribed to two-photon absorption process. Closed-aperture data indicated a sign reversal in nonlinear refraction as the sintering time increased. Third-order nonlinear optical coefficients were estimated, and the largest coefficient was observed for the rod-structured CuNb2O6. Copper niobate exhibited optical limiting behaviour, and the limiting threshold was found to be lowest for microrod structures (~0.21 µJ/cm2). Due to the top-notch third-order nonlinear optical coefficients and excellent limiting behaviour, monoclinic copper niobate microrods can be used as a potential material for utilization as an optical limiter for femtosecond pulses.

  17. Phased waveguide array with fixed tuning elements

    SciTech Connect

    Motley, R.W.; Bernabei, S.; Hooke, W.M.; Paoloni, F.J.

    1980-04-01

    The waveguide grill excites both penetrating lower hybrid waves and surface plasma waves. Quarter wavelength tuning elements attached to the sides of a twin waveguide are shown to reduce the surface wave component by a factor of approx. 3..

  18. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    Polyimide aerogels were considered to serve as a filling for millimeter-wave waveguides. While these waveguides present a slightly higher loss than hollow waveguides, they have less losses than Duroid substrate integrated waveguides (less than 0.15 dB at Ka-band, in a 20 mm section), and exhibit an order of magnitude of mass reduction when compared to commercial waveguides. A Ka-band slotted aerogel-filled-waveguide array was designed, which provided the same gain (9 dBi) as its standard waveguide counterpart, and a slotted aerogel-filled-waveguide array using folded-slots was designed for comparison, obtaining a gain of 9 dB and a bandwidth of 590 MHz.

  19. Optical panel system including stackable waveguides

    DOEpatents

    DeSanto, Leonard; Veligdan, James T.

    2007-11-20

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  20. Optical panel system including stackable waveguides

    DOEpatents

    DeSanto, Leonard; Veligdan, James T.

    2007-03-06

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  1. Lithium purification technique

    DOEpatents

    Keough, R.F.; Meadows, G.E.

    1984-01-10

    A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

  2. Lithium purification technique

    DOEpatents

    Keough, Robert F.; Meadows, George E.

    1985-01-01

    A method for purifying liquid lithium to remove unwanted quantities of nitrogen or aluminum. The method involves precipitation of aluminum nitride by adding a reagent to the liquid lithium. The reagent will be either nitrogen or aluminum in a quantity adequate to react with the unwanted quantity of the impurity to form insoluble aluminum nitride. The aluminum nitride can be mechanically separated from the molten liquid lithium.

  3. Planar waveguide sensor of ammonia

    NASA Astrophysics Data System (ADS)

    Rogoziński, Roman; Tyszkiewicz, Cuma; Karasiński, Paweł; Izydorczyk, Weronika

    2015-12-01

    The paper presents the concept of forming ammonia sensor based on a planar waveguide structure. It is an amplitude sensor produced on the basis of the multimode waveguide. The technological base for this kind of structure is the ion exchange method and the sol-gel method. The planar multimode waveguide of channel type is produced in glass substrate (soda-lime glass of Menzel-Glaser company) by the selective Ag+↔Na+ ion exchange. On the surface of the glass substrate a porous (~40%) silica layer is produced by the sol-gel method. This layer is sensitized to the presence of ammonia in the surrounding atmosphere by impregnation with Bromocresol Purple (BCP) dye. Therefore it constitutes a sensor layer. Spectrophotometric tests carried out showed about 50% reduction of cross-transmission changes of such sensor layer for a wave λ=593 nm caused by the presence of 25% ammonia water vapor in its ambience. The radiation source used in this type of sensor structure is a light emitting diode LED. The gradient channel waveguide is designed for frontal connection (optical glue) with a standard multimode telecommunications waveguide 62.5/125μm.

  4. Loop coupled resonator optical waveguides.

    PubMed

    Song, Junfeng; Luo, Lian-Wee; Luo, Xianshu; Zhou, Haifeng; Tu, Xiaoguang; Jia, Lianxi; Fang, Qing; Lo, Guo-Qiang

    2014-10-06

    We propose a novel coupled resonator optical waveguide (CROW) structure that is made up of a waveguide loop. We theoretically investigate the forbidden band and conduction band conditions in an infinite periodic lattice. We also discuss the reflection- and transmission- spectra, group delay in finite periodic structures. Light has a larger group delay at the band edge in a periodic structure. The flat band pass filter and flat-top group delay can be realized in a non-periodic structure. Scattering matrix method is used to calculate the effects of waveguide loss on the optical characteristics of these structures. We also introduce a tunable coupling loop waveguide to compensate for the fabrication variations since the coupling coefficient of the directional coupler in the loop waveguide is a critical factor in determining the characteristics of a loop CROW. The loop CROW structure is suitable for a wide range of applications such as band pass filters, high Q microcavity, and optical buffers and so on.

  5. Slotted Polyimide-Aerogel-Filled-Waveguide Arrays

    NASA Technical Reports Server (NTRS)

    Rodriguez-Solis, Rafael A.; Pacheco, Hector L.; Miranda, Felix A.; Meador, Mary Ann B.

    2013-01-01

    This presentation discussed the potential advantages of developing Slotted Waveguide Arrays using polyimide aerogels. Polyimide (PI) aerogels offer great promise as an enabling technology for lightweight aerospace antenna systems. PI aerogels are highly porous solids possessing low density and low dielectric permittivity combined with good mechanical properties. For slotted waveguide array applications, there are significant advantages in mass that more than compensate for the slightly higher loss of the aerogel filled waveguide when compared to state of practice commercial waveguide.

  6. Bending loss of terahertz pipe waveguides.

    PubMed

    Lu, Jen-Tang; Hsueh, Yu-Chun; Huang, Yu-Ru; Hwang, Yuh-Jing; Sun, Chi-Kuang

    2010-12-06

    We present an experimental study on the bending loss of terahertz (THz) pipe waveguide. Bending loss of pipe waveguides is investigated for various frequencies, polarizations, core diameters, cladding thicknesses, and cladding materials. Our results indicate that the pipe waveguides with lower guiding loss suffer lower bending loss due to stronger mode confinement. The unexpected low bending loss in the investigated simple leaky waveguide structure promises variety of flexible applications.

  7. Lithium and hematopoiesis.

    PubMed Central

    Barr, R. D.; Galbraith, P. R.

    1983-01-01

    Some of lithium's effects on blood cell formation suggest that the element may be of value in treating hematologic disorders. Lithium enhances granulopoiesis and thereby induces neutrophilia. Two possible mechanisms of action are suggested: a direct action on the pluripotent stem cells, or an inhibition of the suppressor cells (thymus-dependent lymphocytes) that limit hematopoiesis. Lithium also inhibits erythropoiesis. Although most studies use concentrations at or above pharmacologic levels there is evidence that lithium plays a role in normal cell metabolism. PMID:6336655

  8. Lithium nephrotoxicity revisited.

    PubMed

    Grünfeld, Jean-Pierre; Rossier, Bernard C

    2009-05-01

    Lithium is widely used to treat bipolar disorder. Nephrogenic diabetes insipidus (NDI) is the most common adverse effect of lithium and occurs in up to 40% of patients. Renal lithium toxicity is characterized by increased water and sodium diuresis, which can result in mild dehydration, hyperchloremic metabolic acidosis and renal tubular acidosis. The concentrating defect and natriuretic effect develop within weeks of lithium initiation. After years of lithium exposure, full-blown nephropathy can develop, which is characterized by decreased glomerular filtration rate and chronic kidney disease. Here, we review the clinical and experimental evidence that the principal cell of the collecting duct is the primary target for the nephrotoxic effects of lithium, and that these effects are characterized by dysregulation of aquaporin 2. This dysregulation is believed to occur as a result of the accumulation of cytotoxic concentrations of lithium, which enters via the epithelial sodium channel (ENaC) on the apical membrane and leads to the inhibition of signaling pathways that involve glycogen synthase kinase type 3beta. Experimental and clinical evidence demonstrates the efficacy of the ENaC inhibitor amiloride for the treatment of lithium-induced NDI; however, whether this agent can prevent the long-term adverse effects of lithium is not yet known.

  9. [Parkinsonism during lithium use].

    PubMed

    Walrave, T R W M; Bulens, C

    2009-01-01

    Two patients with bipolar disorder had been treated for years with lithium without any complications but began to develop symptoms of rigidity and an altered gait, namely symptoms compatible with a diagnosis of Parkinsonism with an action tremor. In both patients lithium levels were within the therapeutic range. Medication-induced Parkinsonism occurs frequently in patients using antipsychotic medication, but is a rare complication in patients receiving long term treatment with lithium. The lithium dosage was reduced gradually and within a few months all neurological symptoms subsided completely.

  10. Design and implementation of novel nonlinear processes in bulk and waveguide periodic structures

    NASA Astrophysics Data System (ADS)

    Kajal, Meenu

    The telecommunication networks are facing increasing demand to implement all-optical network infrastructure for enabling the wide deployment of new triple play high-speed services (e.g. IPTV, Video On Demand, Voice over IP). One of the challenges with such video broadcasting applications is that these are much more distributed and multi-point in nature unlike the traditional point-to-point communication networks. Currently deployed high-speed electronic components in the optical networks are incapable of handling the unprecedented bandwidth demand for real-time multimedia based broadcasting. The solution essentially lies in increasing the transparency of networks i.e. by replacing high speed signal processing electronics with all-optical signal processors capable of performing signal manipulations such as wavelength switching, time and wavelength division multiplexing, optical pulse compression etc. all in optical domain. This thesis aims at providing an all-optical solution for broadband wavelength conversion and tunable broadcasting, a crucial optical network component, based on quasi-phase-matched wave mixing in nonlinear materials. The quasi phase matching (QPM) technique allows phase matching in long crystal lengths by employing domain-inverted gratings to periodically reverse the sign of nonlinearity, known as periodic poling. This results into new frequency components with high conversion efficiency and has been successfully implemented towards various processes such as second harmonic generation (SHG), sum- and difference- frequency generation (SFG and DFG). Conventionally, the optical networks has an operation window of ˜35 nm centered at 1.55 mum, known as C-band. The wavelength conversion of a signal channel in C-band to an output channel also in the C-band has been demonstrated in periodically poled lithium niobate (PPLN) waveguides via the process of difference frequency mixing, cascaded SHG/DFG and cascaded SFG/DFG. While a DFG process utilized a

  11. Dispersion compensation in slot photonic crystal waveguide

    NASA Astrophysics Data System (ADS)

    Plastun, Alexander; Konyukhov, Andrey

    2015-03-01

    Dispersion tailoring using photonic crystal cladding for slot waveguide is proposed. Numerical modeling based on the Maxwell equation for Te and TM modes of the photonic crystal is performed. Slot waveguide provide high intencity at the central area. Photonic crystal cladding of the slot waveguide allow us to compensate high values of the host glass dispersion.

  12. A general waveguide circuit theory

    NASA Astrophysics Data System (ADS)

    Marks, Roger B.; Williams, Dylan F.

    1992-10-01

    This work generalizes and extends the classical circuit theory of electromagnetic waveguides. Unlike the conventional theory, the present formulation applies to all waveguides composed of linear, isotropic material, even those involving lossy conductors and hybrid mode fields, in a fully rigorous way. Special attention is given to distinguishing the traveling waves, constructed with respect to a well-defined characteristic impedance, from a set of pseudo-waves, defined with respect to an arbitrary reference impedance. Matrices characterizing a linear circuit are defined, and relationships among them, some newly discovered, are derived. New ramifications of reciprocity are developed. Measurement of various network parameters is given extensive treatment.

  13. Hollow glass waveguides: New variations

    NASA Astrophysics Data System (ADS)

    Gibson, Daniel Joseph

    This study is an effort to develop new variations on the infrared silver-silver iodide hollow glass waveguide (HGW) with application specific properties. Four variations are presented: a HGW with a long, gradual taper, a HGW with a rectangular cross-section, curved HGW tips and a new all-dielectric hollow waveguide based on photonic bandgap guidance principles. A hollow glass waveguide tapered over its entire length offers ease of coupling at the proximal end and excellent flexibility at the distal end. Waveguides tapered from 1000 to 500 mum and 700 to 500 mum over 1.5 m were fabricated in this study. Compared to similarly sized non-tapered waveguides, laser losses for the tapered guides were high but decreased when bent. This behavior is contrary to that of non-tapered guides and an iterative ray tracing model was also developed to explain the observed loss characteristics of tapered hollow waveguides. Hollow glass waveguides with round profiles do not maintain the polarization state of the delivered radiation to any appreciable degree. HGWs with large- and small-aspect ratio rectangular cross sections were developed and shown to preserve polarization up to 96%, even when bent. The large aspect ratio guide was able to effectively rotate the transmitted polarization when twisted along its axis. Curved distal tips for medical and dental laser applications were developed by removing the low-OH silica fiber from commercially available stainless steel dental tips, and inserting HGWs of various sizes. The optical performances and heating profiles of the various configurations indicate the tips are suitable for certain medical applications, but the minimum bending radius is limited by the mechanical properties of the glass substrate. A small radii bending loss study confirms that propagating modes periodically couple as the radius of curvature is reduced. Through the application of the photonic bandgap (PBG) guidance, hollow waveguides can be made entirely from

  14. Waveguide Four-Wave Mixing

    DTIC Science & Technology

    1991-10-01

    PL-TR--91-1045 /’--"PL-TR-- AD-A243 555 91-1045 WAVEGUIDE FOUR -WAVE MIXING Thomas B. Simpson Jia-ming Liu JAYCOR San Diego, CA 92186-5154 October...Final Report; May 88 - Mar 91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS WAVEGUIDE FOUR -WAVE MIXING C: F29601-88-C-0023 PE: 62601F PR: 3326 6. AUTHOR(S...for public release; distribution unlimited. 13. ABSTRACT (Maximum 200 words) This program has investigated four -wave mixing (4-win) in non- linear

  15. LITHIUM AND RENAL FUNCTIONS

    PubMed Central

    Sethi, N.; Trivedi, J.K.; Sethi, B.B.

    1987-01-01

    SUMMARY Thirty patients of affective disorder who were on lithium for a year and thirty patients on antidepressant were studied in detail for renal functions. Our observation is that lithium therapy does not lead to any deterioration in kidney functions. The results are discussed. PMID:21927211

  16. Cathode material for lithium batteries

    DOEpatents

    Park, Sang-Ho; Amine, Khalil

    2013-07-23

    A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

  17. Cathode material for lithium batteries

    DOEpatents

    Park, Sang-Ho; Amine, Khalil

    2015-01-13

    A method of manufacture an article of a cathode (positive electrode) material for lithium batteries. The cathode material is a lithium molybdenum composite transition metal oxide material and is prepared by mixing in a solid state an intermediate molybdenum composite transition metal oxide and a lithium source. The mixture is thermally treated to obtain the lithium molybdenum composite transition metal oxide cathode material.

  18. Integrated acousto-optic polarization converter in a ZX-cut LiNbO(3) waveguide superlattice.

    PubMed

    Yudistira, D; Janner, D; Benchabane, S; Pruneri, V

    2009-10-15

    We report an integrated acousto-optic polarization converter exploiting a novel surface acoustic superlattice (S-ASL) transducer. The S-ASL transducer is made of a ZX-cut periodically poled lithium niobate (PPLN) crystal with uniform coplanar electrodes for surface acoustic wave (SAW) generation. For a PPLN period of 20 microm the SAW is excited at an rf of about 190 MHz, while the phase matching occurs at an optical wavelength of around 1456 nm. The measured mode conversion efficiency of 90% at an input rf power of 1 W and the 3 dB optical bandwidth of 2.5 nm confirm the confinement of the SAW between the electrode gap and the constructive interaction along the whole 10 mm electrode length.

  19. Polymeric slot waveguide for photonics sensing

    NASA Astrophysics Data System (ADS)

    Chovan, J.; Uherek, F.

    2016-12-01

    Polymeric slot waveguide for photonics sensing was designed, simulated and studied in this work. The polymeric slot waveguide was designed on commercial Ormocer polymer platform and operates at visible 632.8 nm wavelength. Designed polymeric slot waveguide detects the refractive index change of the ambient material by evanescent field label-free techniques. The motivation for the reported work was to design a low-cost polymeric slot waveguide for sensing arms of integrated Mach-Zehnder interferometer optical sensor with reduced temperature dependency. The minimal dimensions of advanced sensing slot waveguide structure were designed for researcher direct laser writing fabrication by nonlinear two-photon polymerization. The normalized effective refractive index changes of TE and TM fundamental modes in polymeric slot waveguide and slab waveguides were compared. The sensitivity of the normalized effective refractive index changes of TE and TM fundamental modes on refractive index changes of the ambient material was investigated by glucose-water solutions.

  20. Optofluidic waveguides: II. Fabrication and structures

    PubMed Central

    Schmidt, Holger

    2011-01-01

    We review fabrication methods and common structures for optofluidic waveguides, defined as structures capable of optical confinement and transmission through fluid filled cores. Cited structures include those based on total internal reflection, metallic coatings, and interference based confinement. Configurations include optical fibers and waveguides fabricated on flat substrates (integrated waveguides). Some examples of optofluidic waveguides that are included in this review are Photonic Crystal Fibers (PCFs) and two-dimensional photonic crystal arrays, Bragg fibers and waveguides, and Anti Resonant Reflecting Optical Waveguides (ARROWs). An emphasis is placed on integrated ARROWs fabricated using a thin-film deposition process, which illustrates how optofluidic waveguides can be combined with other microfluidic elements in the creation of lab-on-a-chip devices. PMID:21603122

  1. Optical waveguides for chemical sensing

    NASA Astrophysics Data System (ADS)

    Burgess, Lloyd W.

    1992-07-01

    Possibilities of employing thin film optical waveguides for chemical analysis are reviewed. Particular attention is given to the use of integrated or planar optical elements in sensors which may be applied to continuous or in situ monitoring in biomedical, environmental, and chemical processes.

  2. Birefringence compensated arrayed waveguide grating

    NASA Astrophysics Data System (ADS)

    Zou, Jun; Xia, Xiang; Lang, Tingting; He, Jian-Jun

    2014-10-01

    In this paper we review our work on birefringence compensated arrayed waveguide grating. We elaborate on a birefringence compensation technique based on angled star couplers in arrayed waveguide grating (AWG) and discuss several demonstrations both in low-index-contrast and high-index-contrast material systems. A 16-channel AWG with 100GHz channel spacing for DWDM application is designed and fabricated in silica-based low-index-contrast waveguide. The experimental results confirm that the polarization-dependent wavelength shift (PDλ) can be tuned by varying the incident/diffraction angle at the star couplers and a birefringence-free property can be achieved without additional fabrication process as compared to conventional AWG. A further validation of this technique is demonstrated in high-index-contrast silicon-on-insulator waveguide, in combination with different diffraction orders for TE and TM polarizations. A birefringence compensated silicon nanowire AWG for CWDM optical interconnects is designed and fabricated. The theoretical and experimental results show that the PDλ can be reduced from 380-420nm to 0.5-3.5 nm, below 25% of the 3 dB bandwidth of the channel response in the wavelength range of 1500 to 1600nm.

  3. Polymer Waveguides for Quantum Information

    DTIC Science & Technology

    2005-01-01

    design, fabrication and testing of slab waveguides made of EO polymer and covers the initial phase of installation, testing and use of the spin ... coating system to make a few simple slabs with the anticipation of testing those for coupling and other processes.

  4. Lithium metal oxide electrodes for lithium batteries

    DOEpatents

    Thackeray, Michael M.; Kim, Jeom-Soo; Johnson, Christopher S.

    2008-01-01

    An uncycled electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula Li.sub.(2+2x)/(2+x)M'.sub.2x/(2+x)M.sub.(2-2x)/(2+x)O.sub.2-.delta., in which 0.ltoreq.x<1 and .delta. is less than 0.2, and in which M is a non-lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. Methods of preconditioning the electrodes are disclosed as are electrochemical cells and batteries containing the electrodes.

  5. Investigation of Local Structures in Layered Niobates by Solid-state NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Ting

    Research on ion-exchangeable layered niobates has attracted great attention due to their unique structures and corresponding variations in properties and applications, such as ion conductors, solid acids, and water splitting catalysts. Families of layered niobates include double-layered or triple-layered Dion-Jacobson type perovskites (ALaNb2O7, A = Cs, Rb, K, H; AM2Nb3O10, A = Rb, K, H; M = Sr, Ca), layered niobates with both edge and corner sharing of NbO6 octahedra (KNb3O8, HNb3O6, Nb 6O17 and H4Nb6O17) and many others. Lately, more developments in the layered niobates through a variety of topochemical manipulations have been achieved. The topochemical reactions include ion exchange, exfoliation, substitution, and etc. As a result, many new materials have been successfully prepared, for example, solid solutions (ALa2NbTi2O10, ACaLaNb2TiO 10 and ACa2Nb3-xTaxO10, etc.), nanosheets (HNb3O8, H4Nb6O17, HLaNb2O7, HCa2Nb3O10, etc., to intercalate with organic molecules such as tetrabutylammonium hydroxide or n-butylamines), and nanoscrolls (from H2K2Nb 6O17). While these structural modifications often induce improvements in properties, the fundamental mechanisms of improvements in properties upon the modifications, especially local structural arrangements are poorly understood, which is often limited by structural characterizations. Particularly, the characterizations of the exfoliated nanosheets can be difficult by conventional X-ray diffraction (XRD) method due to disordered structures. Alternatively, solid-state nuclear magnetic resonance (NMR) spectroscopy is a useful tool to study local structures in solids. The structural information can be extracted by examining intrinsic interactions, such as quadrupolar, chemical shielding, and dipolar interactions, which are all associated with local environments surrounding a specific nucleus, 1H or 93Nb in layered niobates. The ultimate goal of this dissertation is to understand the relationships between local structures of

  6. Theoretical Study of Monolayer and Double-Layer Waveguide Love Wave Sensors for Achieving High Sensitivity.

    PubMed

    Li, Shuangming; Wan, Ying; Fan, Chunhai; Su, Yan

    2017-03-22

    Love wave sensors have been widely used for sensing applications. In this work, we introduce the theoretical analysis of the monolayer and double-layer waveguide Love wave sensors. The velocity, particle displacement and energy distribution of Love waves were analyzed. Using the variations of the energy repartition, the sensitivity coefficients of Love wave sensors were calculated. To achieve a higher sensitivity coefficient, a thin gold layer was added as the second waveguide on top of the silicon dioxide (SiO₂) waveguide-based, 36 degree-rotated, Y-cut, X-propagating lithium tantalate (36° YX LiTaO₃) Love wave sensor. The Love wave velocity was significantly reduced by the added gold layer, and the flow of wave energy into the waveguide layer from the substrate was enhanced. By using the double-layer structure, almost a 72-fold enhancement in the sensitivity coefficient was achieved compared to the monolayer structure. Additionally, the thickness of the SiO₂ layer was also reduced with the application of the gold layer, resulting in easier device fabrication. This study allows for the possibility of designing and realizing robust Love wave sensors with high sensitivity and a low limit of detection.

  7. Structural refinement and optical band gap studies of manganese-doped modified sodium potassium lithium niobate lead — piezoelectric ceramics

    NASA Astrophysics Data System (ADS)

    Mishra, S. K.; Mishra, R. K.; Brajesh, Kumar; Ray, Rajyavardhan; Himanshu, A. K.; Pandey, H. K.; Singh, N. K.

    2014-05-01

    Li-doped NKLN ceramic (Na0.5 K0.5)0.935Li0.065NbO3 (NKLN935) in pure and MnO2 doped compositions have been revisited to carry out a detailed analysis of the structural and optical properties. Rietveld analysis of the X-ray diffraction (XRD) pattern reveals the system to be tetragonal (space group P4mm). UV-Visible (UV-Vis) spectroscopy and an equivalent Kubelka-Munk function is used to obtain the optical band gap values. It is reported that with increasing Mn doping, the band gap values decreases, which has been analyzed and understood in terms of the tetragonal structure and is found to be consistent with dielectric properties.

  8. Continuous tuning of a microlaser-pumped optical parametric generator by use of a cylindrical periodically poled lithium niobate crystal.

    PubMed

    Fève, Jean-Philippe; Boulanger, Benoît; Ménaert, Bertrand; Pacaud, Olivier

    2003-06-15

    An optical parametric generator with a cylindrical periodically poled LiNbO3 crystal and a Nd:YAG commercial microchip pump laser yields continuous tuning of the emitted wavelengths over a broad spectral range (1.42-1.7 microm and 2.8-4.2 microm), with large efficiency, a high repetition rate, and low divergence, in a compact and stable device.

  9. Type-I cascaded quadratic soliton compression in lithium niobate: Compressing femtosecond pulses from high-power fiber lasers

    SciTech Connect

    Bache, Morten; Wise, Frank W.

    2010-05-15

    The output pulses of a commercial high-power femtosecond fiber laser or amplifier are typically around 300-500 fs with wavelengths of approximately 1030 nm and tens of microjoules of pulse energy. Here, we present a numerical study of cascaded quadratic soliton compression of such pulses in LiNbO{sub 3} using second-harmonic generation in a type-I phase-matching configuration. We find that because of competing cubic material nonlinearities, compression can only occur in the nonstationary regime, where group-velocity-mismatch-induced Raman-like nonlocal effects prevent compression to less than 100 fs. However, the strong group-velocity dispersion implies that the pulses can achieve moderate compression to durations of less than 130 fs in available crystal lengths. Most of the pulse energy is conserved because the compression is moderate. The effects of diffraction and spatial walk-off are addressed, and in particular the latter could become an issue when compressing such long crystals (around 10 cm long). We finally show that the second harmonic contains a short pulse locked to the pump and a long multi-picosecond red-shifted detrimental component. The latter is caused by the nonlocal effects in the nonstationary regime, but because it is strongly red-shifted to a position that can be predicted, we show that it can be removed using a bandpass filter, leaving a visible component of less than 100 fs at {lambda}=515 nm with excellent pulse quality.

  10. Stimulated Photorefractive Backscatter Leading to Six-Wave Mixing and Phase Conjugation in Iron Doped Lithium Niobate (Preprint)

    DTIC Science & Technology

    2007-04-01

    anisotropic higher-order generation and mutually pumped phase conjugation in photore&active barium titanate ," Photore&active Fiber and Crystal Devices...strong stimulated backscatter leading to self-pumped phase conjugation has been observed in LiNb03:Mg at 351 nm where the PR sample exhibits large...coatings, and thicknesses are used as PR samples . The crystals and their different parameters are 3 presented in Table 1. All crystals have a cross

  11. Temperature insensitive, high-power cascaded optical parametric oscillator based on an aperiodically poled lithium niobate crystal.

    PubMed

    Chen, Tao; Jiang, Peipei; Wu, Bo; Shu, Rong; Hu, Chengzhi; Shen, Yonghang

    2014-11-03

    We report a novel temperature insensitive, APMgLN-based, high-power cascaded optical parametric oscillator (OPO) pumped by an Ytterbium-doped fiber laser. A monolithic APMgLN crystal was designed to compensate the phase mismatches for the nonlinear conversions from the pump to the idler and the primary signal to the idler simultaneously in a wide temperature range. Efficient parametric conversion with pump-to-idler conversion efficiency over 15% and slope efficiency higher than 20% was realized from 25 °C to 55 °C. The idler wavelength was down-shifted from 3.82 μm to 3.78 μm accordingly during the temperature rise. The highest idler power of 4.1 W at 3.8 μm under the pump power of 26.5 W was recorded which was improved by ~32% in pump-to-idler conversion efficiency when compared with the PPMgLN-based conventional OPO, in which the highest idler output power was 3.1W under the same pump and thermal condition.

  12. Surface plasmon polariton excitation by electrostatic modulation and phase grating in indium-tin-oxide coated lithium niobate slabs

    SciTech Connect

    Wang, Hao; Zhang, Jingwen; Zhao, Hua

    2015-08-14

    Excitation of surface plasmon polaritons (SPPs) in a non-metal system in visible regime is discussed. With the assistance of phase grating resulted from photorefractive effect and electrostatic modulation of ITO induced by strong photovoltaic effect in iron-doped LiNbO{sub 3}, phase matching condition could be satisfied for SPP excitation in this semiconductor/dielectric system. Both the phase grating instead of metal grating and electrostatic modulation of semiconductor could be used for the design of tunable plasmonic devices based on nonlinear photorefractive crystals.

  13. Holographic recording in a doubly doped lithium niobate crystal with two wavelengths: a blue laser diode and a green laser

    NASA Astrophysics Data System (ADS)

    Komori, Yuichi; Ishii, Yukihiro

    2010-08-01

    A doubly-doped LiNbO3 (LN) crystal has been well used as a nonvolatile two-wavelength recording material. By using two levels of the crystal, two-kind holograms can be recorded on one crystal; a hologram is recorded with a 405-nm blue laser diode (LD) for a deep Mn level, and another hologram is with a 532-nm green laser for a shallow Fe level. The recording capacity doubles. A 780-nm LD is non-volatile reconstructing source since the LD line is insensitive to both levels. Multiplexed reconstructed images are demonstrated by using a sharp angular selectivity of a volume LN crystal keeping Bragg condition with spherical reconstructions.

  14. Theoretical analysis of surface acoustic wave propagating properties of Y-cut nano lithium niobate film on silicon dioxide

    SciTech Connect

    Chen, Jing Zhang, Qiaozhen; Han, Tao; Zhou, Liu; Tang, Gongbin; Liu, Boquan; Ji, Xiaojun

    2015-08-15

    The surface acoustic wave (SAW) propagating characteristics of Y-cut nano LiNbO{sub 3} (LN) film on SiO{sub 2}/LN substrate have been theoretically calculated. The simulated results showed a shear horizontal (SH) SAW with enhanced electromechanical coupling factor K{sup 2} owing to a dimensional effect of the nanoscale LN film. However, a Rayleigh SAW and two other resonances related to thickness vibrations caused spurious responses for wideband SAW devices. These spurious waves could be fully suppressed by properly controlling structural parameters including the electrode layer height, thickness, and the Euler angle (θ) of the LN thin film. Finally, a pure SH SAW was obtained with a wide θ range, from 0° to 5° and 165° to 180°. The largest K{sup 2} achieved for the pure SH SAW was about 35.1%. The calculated results demonstrate the promising application of nano LN film to the realization of ultra-wideband SAW devices.

  15. Effect of size and composition on the second harmonic generation from lithium niobate powders at different excitation wavelengths

    NASA Astrophysics Data System (ADS)

    Sánchez-Dena, O.; García-Ramírez, E. V.; Fierro-Ruiz, C. D.; Vigueras-Santiago, E.; Farías, Rurik; Reyes-Esqueda, J. A.

    2017-03-01

    LiNbO3 microcrystalline systems, possessing almost stoichiometric composition, were produced by varying the temperature and time parameters in the annealing processes following a mechanochemical reaction of raw powders. SHG from these samples, detected for every fundamental wavelength in the range 800–1300 nm, and being maximal at a certain wavelength, λ max, for each sample, has been addressed to a random scattering of the induced nonlinear polarizations. Possible tuning of λ max could be ascribed to control of composition and grain size of the sample. Random orientation of the produced nanocrystallites was verified since no dependence for SHG intensity on incident polarization was observed.

  16. Sub-Nanosecond Infrared Optical Parametric Pulse Generation in Periodically Poled Lithium Niobate Pumped by a Seeded Fiber Amplifier

    DTIC Science & Technology

    2008-02-01

    element, such as erbium or ytterbium, to act as a gain medium. Erbium Doped Fiber Amplifiers ( EDFAs ) have been used by the telecommunications industry...FIBER AMPLIFIER Matthew D. Cocuzzi Electro-Optical Countermeasures Technology Branch Electro-Optical Sensor Technology Division...BRIAN C. FORD, Col, USAF Chief, EO Sensor Technology Division Sensors Directorate This report is published in the interest of

  17. Waveguide ring coupling design of MOG

    NASA Astrophysics Data System (ADS)

    Ji, Xiang; Li, Zi-li; Chen, Yuan-you; Qin, Xiao-hu; Lv, Xin

    2010-10-01

    The key technology of micro optic gyroscopes (MOGs) is to fabricate low-loss waveguide and use coupling technology to form reciprocal structure. The main topic in this paper is to study the coupling structure of MOG's spiral-ring waveguide. Using for the reference of fiber's low-loss character, the fiber-preform project is chosen as optimization means. According to the singlemode conditions, the width and thickness of rectangle waveguide can be calculated. The bend loss waveguide can decrease by means of introducing an offset at the junction of two waveguides and etching groove at the outside of bend waveguide. In this article intersection waveguide is designed to reduce the difficulty of coupling processing. Light in-and-out port coupled at opposite side is choosen for machining easiness in experiment.What's more, the edge-coupling technology being put forward to keep light transmit along the same rotary direction. An efficient means is introduced, which uses angle 45°to reflect the light to couple two waveguide at inside-end or outside-end, and outside-end coupling is chosen for processing convenience in the design. In experiment, the waveguide be fabricated by thick photoresist AZ4620, etched by RIE, When the angle of wafer and ion is set 85°, the angle of one sidewall can be etched almost 45°. It's benefit to design the coupling structure of MOG's spiral-ring waveguide.

  18. Tunable radio frequency photonics filter using a comb-based optical tapped delay line with an optical nonlinear multiplexer.

    PubMed

    Ziyadi, Morteza; Mohajerin-Ariaei, Amirhossein; Chitgarha, Mohammad Reza; Khaleghi, Salman; Almaiman, Ahmed; Cao, Yinwen; Abouzaid, Amin; Shamee, Bishara; Tur, Moshe; Paraschis, Loukas; Langrock, Carsten; Fejer, Martin M; Touch, Joseph D; Willner, Alan E

    2015-07-15

    A radio frequency (RF) photonic filter is experimentally demonstrated using an optical tapped delay line (TDL) based on an optical frequency comb and a periodically poled lithium niobate (PPLN) waveguide as multiplexer. The approach is used to implement RF filters with variable bandwidth, shape, and center-frequency.

  19. Lithium Combustion: A Review

    DTIC Science & Technology

    1990-12-01

    lithium vapors generated with air formed an intense white flame that produced branched- chain condensation aerosol particles, of concentrations 򓆄 mg/im3...generated chain -aggregate lithium combustion aerosols in dry, COg-free air prior to reaction with 0, 0.10, 0.50, 1.0, 1.75, or 5.0% CO in air at a...In order to burn in gaseous chlorine or in bromine or iodine vapor, lithium needs to be heated. With iodine vapor, the reaction is accompanied by

  20. Sealed Lithium Inorganic Battery

    DTIC Science & Technology

    1976-08-01

    MuWrn , 1,ad iw..am m4 IdM.D to We"L406W) Inorganic Electrolyte lattery Carbon Cathode Evaluation Thionyl Chloride Gas Generation Lithium C ell sign...hardware surface to carry the reductIon of thionyl chloride when in contact with lithium (self discharge) and the corro,’ion of hardware materials... Lithium - Aluminum Chloride 10) AOSTSAC? (Cmawl/e o ade H .m.eewr W MWO, AV 600 nwe w) Stdies were continued of the effects of hardware materials on the

  1. Lithium cell test results

    NASA Technical Reports Server (NTRS)

    Bragg, B. J.

    1977-01-01

    Three lithium SO2 cells, two lithium CF cells, and a vinyl chloride cell, all with crimped seals, and all strictly experimental, were independently discharged on resistors. Three temperatures were used and several different storage temperatures. Discharge rate generally on the nominal discharges were 0.1 amp, 0.5 amp, and 1 amp. Tests results show that the crimp seals are inadequate, especially for the SO2 cells. Normal discharges present no hazards. All cells discharge to zero. The problem of lithium cell explosions, such as occurred during off-limits testing, is discussed.

  2. Lithium Dendrite Formation

    SciTech Connect

    2015-03-06

    Scientists at the Department of Energy’s Oak Ridge National Laboratory have captured the first real-time nanoscale images of lithium dendrite structures known to degrade lithium-ion batteries. The ORNL team’s electron microscopy could help researchers address long-standing issues related to battery performance and safety. Video shows annular dark-field scanning transmission electron microscopy imaging (ADF STEM) of lithium dendrite nucleation and growth from a glassy carbon working electrode and within a 1.2M LiPF6 EC:DM battery electrolyte.

  3. Lithium metal oxide electrodes for lithium batteries

    DOEpatents

    Thackeray, Michael M.; Johnson, Christopher S.; Amine, Khalil; Kang, Sun-Ho

    2010-06-08

    An uncycled preconditioned electrode for a non-aqueous lithium electrochemical cell including a lithium metal oxide having the formula xLi.sub.2-yH.sub.yO.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 in which 0lithium metal ion with an average trivalent oxidation state selected from two or more of the first row transition metals or lighter metal elements in the periodic table, and M' is one or more ions with an average tetravalent oxidation state selected from the first and second row transition metal elements and Sn. The xLi.sub.2-yH.sub.y.xM'O.sub.2.(1-x)Li.sub.1-zH.sub.zMO.sub.2 material is prepared by preconditioning a precursor lithium metal oxide (i.e., xLi.sub.2M'O.sub.3.(1-x)LiMO.sub.2) with a proton-containing medium with a pH<7.0 containing an inorganic acid. Methods of preparing the electrodes are disclosed, as are electrochemical cells and batteries containing the electrodes.

  4. Electret-based Unsteady Thermal Energy Harvester using Potassium Tantalate Niobate Crystal

    NASA Astrophysics Data System (ADS)

    Xie, Hong; Morimoto, Kenichi; Suzuki, Yuji

    2016-11-01

    An electret-based unsteady thermal energy harvester is proposed using potassium tantalate niobate (KTa1-xNbxO3, KTN) as a dielectric for the capacitor. By connecting in series the capacitor and an electret serving as a permanent voltage source, the capacitance change with temperature fluctuations alters the amount of induced charges thereby produces the external current. By using KTN having extremely-large temperature coefficient of permittivity together with the CYTOP electret, the output power of 572 nJ has been obtained from one heating cycle, which corresponds to 20 times higher output power than the previous result with BaTiO3.

  5. Structural, topographical and electrical properties of cerium doped strontium barium niobate (Ce:SBN60) ceramics

    NASA Astrophysics Data System (ADS)

    Raj, S. Gokul; Mathivanan, V.; Kumar, G. Ramesh; Yathavan, S.; Mohan, R.

    2016-05-01

    Tungsten bronze type cerium doped strontium barium niobate (Ce:SBN - Sr0.6B0.4Nb2O6) ceramics were synthesized by solid state process. Cerium was used as dopant to improve its electrical properties. Influence of Ce+ ions on the photoluminescence properties was investigated in detail. The grain size topographical behavior of SBN powders and their associated abnormal grain growth (AGG) were completely analyzed through SEM studies. Finally dielectric, measurement discusses about the broad phase transition observed due to cerium dopant The results were discussed in detail.

  6. Ultrashort pulse chirp measurement via transverse second-harmonic generation in strontium barium niobate crystal

    SciTech Connect

    Trull, J.; Wang, B.; Parra, A.; Vilaseca, R.; Cojocaru, C.; Sola, I.; Sheng, Y.

    2015-06-01

    Pulse compression in dispersive strontium barium niobate crystal with a random size and distribution of the anti-parallel orientated nonlinear domains is observed via transverse second harmonic generation. The dependence of the transverse width of the second harmonic trace along the propagation direction allows for the determination of the initial chirp and duration of pulses in the femtosecond regime. This technique permits a real-time analysis of the pulse evolution and facilitates fast in-situ correction of pulse chirp acquired in the propagation through an optical system.

  7. Direct writing of ferroelectric domains on strontium barium niobate crystals using focused ultraviolet laser light

    SciTech Connect

    Boes, Andreas; Crasto, Tristan; Steigerwald, Hendrik; Mitchell, Arnan; Wade, Scott; Frohnhaus, Jakob; Soergel, Elisabeth

    2013-09-30

    We report ferroelectric domain inversion in strontium barium niobate (SBN) single crystals by irradiating the surface locally with a strongly focused ultraviolet (UV) laser beam. The generated domains are investigated using piezoresponse force microscopy. We propose a simple model that allows predicting the domain width as a function of the irradiation intensity, which indeed applies for both SBN and LiNbO{sub 3}. Evidently, though fundamentally different, the domain structure of both SBN and LiNbO{sub 3} can be engineered through similar UV irradiation.

  8. Field induced polarization and magnetization behaviour of Gd-doped lead magnesium niobate ceramics

    NASA Astrophysics Data System (ADS)

    Pandey, Adityanarayan; Gupta, Surya Mohan; Nigam, Arun Kumar

    2016-05-01

    Both superparaelectric and superparamagnetic behaviour has been observed in rare earth magnetic ion Gd3+ doped Lead Magnesium Niobate (Gd-PMN). Field induced polarization and magnetization studies reveal hystresis loss free P-E and M-H loop at 300K and 5K, respectively. Temperature dependence of inverse susceptibility plot shows deviation at a temperature "td" when fitted with the Curie-Weiss law. This deviation has been attributed to transition from paramagnetic to superparamagnetic behaviour as reported in amorphous Pd-Ni-Fe-P alloys.

  9. Porosity Dependence of Piezoelectric Properties for Porous Potassium Niobate System Ceramics

    NASA Astrophysics Data System (ADS)

    Wada, S.; Mase, Y.; Shimizu, S.; Maeda, K.; Fujii, I.; Nakashima, K.; Pulpan, P.; Miyajima, N.

    2011-10-01

    Porous potassium niobate (KNbO3, KN) system ceramics were prepared by a conventional sintering method using carbon black (CB) nanoparticles. First, KN nanoparticles with a size of 100 nm was mixed with CB nanoparticles and binder using ball milling with ethanol. The mixture was dried, and pressed into pellets using uniaxial pressing. After binder burnout, these ceramics was sintered in air. Their piezoelectric properties were measured and discussed a relationship between porosity and piezoelectric properties. As the results, with increasing porosity, piezoelectric g33 constant increased significantly, which suggested that porous ceramics were effective for stress sensor application.

  10. APPARATUS FOR THE PRODUCTION OF LITHIUM METAL

    DOEpatents

    Baker, P.S.; Duncan, F.R.; Greene, H.B.

    1961-08-22

    Methods and apparatus for the production of high-purity lithium from lithium halides are described. The apparatus is provided for continuously contacting a molten lithium halide with molten barium, thereby forming lithium metal and a barium halide, establishing separate layers of these reaction products and unreacted barium and lithium halide, and continuously withdrawing lithium and barium halide from the reaction zone. (AEC)

  11. Wideband unbalanced waveguide power dividers and combiners

    SciTech Connect

    Halligan, Matthew; McDonald, Jacob Jeremiah; Strassner, II, Bernd H.

    2016-05-17

    The various technologies presented herein relate to waveguide dividers and waveguide combiners for application in radar systems, wireless communications, etc. Waveguide dividers-combiners can be manufactured in accordance with custom dimensions, as well as in accordance with waveguide standards such that the input and output ports are of a defined dimension and have a common impedance. Various embodiments are presented which can incorporate one or more septum(s), one or more pairs of septums, an iris, an input matching region, a notch located on the input waveguide arm, waveguide arms having stepped transformer regions, etc. The various divider configurations presented herein can be utilized in high fractional bandwidth applications, e.g., a fractional bandwidth of about 30%, and RF applications in the Ka frequency band (e.g., 26.5-40 GHz).

  12. Flattened dispersion in silicon slot waveguides.

    PubMed

    Zhang, Lin; Yue, Yang; Beausoleil, Raymond G; Willner, Alan E

    2010-09-13

    We propose a silicon strip/slot hybrid waveguide that produces flattened dispersion of 0 ± 16 ps/(nm∙km), over a 553-nm wavelength range, which is 20 times flatter than previous results. Different from previously reported slot waveguides, the strip/slot hybrid waveguide employs the mode transition from a strip mode to a slot mode to introduce unique waveguide dispersion. The flat dispersion profile is featured by three zero-dispersion wavelengths, which is obtained for the first time in on-chip silicon waveguides, to the best of our knowledge. The waveguide exhibits flattened dispersion from 1562-nm to 2115-nm wavelength, which is potentially useful for both telecom and mid-infrared applications.

  13. Plasmonic coaxial waveguide-cavity devices.

    PubMed

    Mahigir, Amirreza; Dastmalchi, Pouya; Shin, Wonseok; Fan, Shanhui; Veronis, Georgios

    2015-08-10

    We theoretically investigate three-dimensional plasmonic waveguide-cavity structures, built by side-coupling stub resonators that consist of plasmonic coaxial waveguides of finite length, to a plasmonic coaxial waveguide. The resonators are terminated either in a short or an open circuit. We show that the properties of these waveguide-cavity systems can be accurately described using a single-mode scattering matrix theory. We also show that, with proper choice of their design parameters, three-dimensional plasmonic coaxial waveguide-cavity devices and two-dimensional metal-dielectric-metal devices can have nearly identical transmission spectra. Thus, three-dimensional plasmonic coaxial waveguides offer a platform for practical implementation of two-dimensional metal-dielectric-metal device designs.

  14. Lithium and Autophagy

    PubMed Central

    2014-01-01

    Lithium, a drug used to treat bipolar disorders, has a variety of neuroprotective mechanisms, including autophagy regulation, in various neuropsychiatric conditions. In neurodegenerative diseases, lithium enhances degradation of aggregate-prone proteins, including mutated huntingtin, phosphorylated tau, and α-synuclein, and causes damaged mitochondria to degrade, while in a mouse model of cerebral ischemia and Alzheimer’s disease autophagy downregulation by lithium is observed. The signaling pathway of lithium as an autophagy enhancer might be associated with the mammalian target of rapamycin (mTOR)-independent pathway, which is involved in myo-inositol-1,4,5-trisphosphate (IP3) in Huntington’s disease and Parkinson’s disease. However, the mTOR-dependent pathway might be involved in inhibiting glycogen synthase kinase-3β (GSK3β) in other diseases. Lithium’s autophagy-enhancing property may contribute to the therapeutic benefit of patients with neuropsychiatric disorders. PMID:24738557

  15. Lithium Sulfuryl Chloride Battery.

    DTIC Science & Technology

    Primary batteries , Electrochemistry, Ionic current, Electrolytes, Cathodes(Electrolytic cell), Anodes(Electrolytic cell), Thionyl chloride ...Phosphorus compounds, Electrical conductivity, Calibration, Solutions(Mixtures), Electrical resistance, Performance tests, Solvents, Lithium compounds

  16. Lithium drifted germanium system

    NASA Technical Reports Server (NTRS)

    Fjarlie, E. J.

    1969-01-01

    General characteristics of the lithium-drifted germanium photodiode-Dewar-preamplifier system and particular operating instructions for the device are given. Information is included on solving operational problems.

  17. Solid-state lithium battery

    SciTech Connect

    Ihlefeld, Jon; Clem, Paul G; Edney, Cynthia; Ingersoll, David; Nagasubramanian, Ganesan; Fenton, Kyle Ross

    2014-11-04

    The present invention is directed to a higher power, thin film lithium-ion electrolyte on a metallic substrate, enabling mass-produced solid-state lithium batteries. High-temperature thermodynamic equilibrium processing enables co-firing of oxides and base metals, providing a means to integrate the crystalline, lithium-stable, fast lithium-ion conductor lanthanum lithium tantalate (La.sub.1/3-xLi.sub.3xTaO.sub.3) directly with a thin metal foil current collector appropriate for a lithium-free solid-state battery.

  18. Digital waveguide adiabatic passage part 1: theory

    NASA Astrophysics Data System (ADS)

    Vaitkus, Jesse A.; Steel, M. J.; Greentree, Andrew D.

    2017-03-01

    Spatial adiabatic passage represents a new way to design integrated photonic devices. In conventional adiabatic passage designs require smoothly varying waveguide separations. Here we show modelling of adiabatic passage devices where the waveguide separation is varied digitally. Despite digitisation, our designs show robustness against variations in the input wavelength and refractive index contrast of the waveguides relative to the cladding. This approach to spatial adiabatic passage opens new design strategies and hence the potential for new photonics devices.

  19. Shift multiplexing by planar waveguide referencing

    NASA Astrophysics Data System (ADS)

    Yi, Tao; Zhang, Jiasen; Yan, Lifen; Gong, Qihuang

    2005-09-01

    We present a new method with which to implement shift multiplexing by planar waveguide referencing. In this method, a planar waveguide is used to steer the reference beam, and we implement shift multiplexing by shifting the recording medium. A spatial selectivity as high as 1.1 μm is obtained. By using waveguide referencing we can make a compact and simple holographic system.

  20. Dispersion Characteristics of a Dielectric Loaded Waveguide,

    DTIC Science & Technology

    1984-07-30

    NATIONAL BUREAU OF STANOAODS-1963-A ., ’I A NSWC TR 84-338 00 In ’DISPERSION CHARACTERISTICS OF A SDIELECTRIC LOADED WAVEGUIDE By H. CROSBY J. CHOE Y...4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED DISPERSION CHARACTERISTICS OF A DIELECTRIC LOADED WAVEGUIDE S. PERFORMING ORG. REPORT...SUPPLEMENTARY NOTES S. KEY WORDS (Continue on reverse aide it necessary and Identify by block number) Dielectric Loaded Waveguide ) " Resonant Cavity) a

  1. Optical fiber having wave-guiding rings

    DOEpatents

    Messerly, Michael J.; Dawson, Jay W.; Beach, Raymond J.; Barty, Christopher P. J.

    2011-03-15

    A waveguide includes a cladding region that has a refractive index that is substantially uniform and surrounds a wave-guiding region that has an average index that is close to the index of the cladding. The wave-guiding region also contains a thin ring or series of rings that have an index or indices that differ significantly from the index of the cladding. The ring or rings enable the structure to guide light.

  2. Constitutive Parameter Measurement Using Double Ridge Waveguide

    DTIC Science & Technology

    2013-03-01

    CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Nathan J. Lehman, Captain, USAF AFIT-ENG-13-M-30 DEPARTMENT OF THE AIR FORCE...copyright protection in the United States. AFIT-ENG-13-M-30 CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Presented to the Faculty...PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE Nathan J. Lehman, B.S.E.E. Captain, USAF Approved: Michael Havrilla, PhD (Chairman) Maj Milo Hyde, PhD

  3. Lithium battery management system

    DOEpatents

    Dougherty, Thomas J [Waukesha, WI

    2012-05-08

    Provided is a system for managing a lithium battery system having a plurality of cells. The battery system comprises a variable-resistance element electrically connected to a cell and located proximate a portion of the cell; and a device for determining, utilizing the variable-resistance element, whether the temperature of the cell has exceeded a predetermined threshold. A method of managing the temperature of a lithium battery system is also included.

  4. Analysis of piezoelectric ultrasonic transducers attached to waveguides using waveguide finite elements.

    PubMed

    Loveday, Philip W

    2007-10-01

    A finite-element modeling procedure for computing the frequency response of piezoelectric transducers attached to infinite constant cross-section waveguides, as encountered in guided wave ultrasonic inspection, is presented. Two-dimensional waveguide finite elements are used to model the waveguide. Conventional three-dimensional finite elements are used to model the piezoelectric transducer. The harmonic forced response of the waveguide is used to obtain a dynamic stiffness matrix (complex and frequency dependent), which represents the waveguide in the transducer model. The electrical and mechanical frequency response of the transducer, attached to the waveguide, can then be computed. The forces applied to the waveguide are calculated and are used to determine the amplitude of each mode excited in the waveguide. The method is highly efficient compared to time integration of a conventional finite-element model of a length of waveguide. In addition, the method provides information about each mode that is excited in the waveguide. The method is demonstrated by modeling a sandwich piezoelectric transducer exciting a waveguide of rectangular cross section, although it could be applied to more complex situations. It is expected that the modeling method will be useful during the optimization of piezoelectric transducers for exciting specific wave propagation modes in waveguides.

  5. Ground-slot waveguide laser

    SciTech Connect

    Chenausky, P.; Drinkwater, E.H.; Laughman, L.M.

    1985-03-18

    A method of fabricating CO/sub 2/ waveguide-type lasers of the type comprising a slot formed in a broad surface of a hard ceramic material, comprising grinding the slot in a conventional surface grinding machine in two steps. The first step utilizes a coarse grinding wheel and the second a finer grinding wheel. The resultant laser cavity can produce high optical-power output when provided with RF excitation.

  6. Fluorescent immunosensors using planar waveguides

    NASA Astrophysics Data System (ADS)

    Herron, James N.; Caldwell, Karin D.; Christensen, Douglas A.; Dyer, Shellee; Hlady, Vladimir; Huang, P.; Janatova, V.; Wang, Hiabo K.; Wei, A. P.

    1993-05-01

    The goal of our research program is to develop competitive and sandwich fluoroimmunoassays with high sensitivity and fast response time, that do not require external reagents. Our approach to this problem is to employ an optical immunoassay based on total internal reflection fluorescence (TIRF). Specifically, monoclonal antibodies are immobilized on a planar waveguide. Total internal reflection of light in the planar waveguide sets up an evanescent field which extends about 2000 angstroms from the interface. In the competitive immunoassay, a fluorescent label is coupled to a small synthetic antigen which is packaged with the antibody. In the absence of analyte, the fluorescently labeled antigen binds to the antibody and is excited by the evanescent field. Upon the addition of analyte, the fluorescently labeled antigen molecules are displaced by unlabeled antigen molecules and diffuse out of the evanescent field. In the sandwich assay, a primary or `capture' antibody is immobilized on the planar waveguide, and a secondary or `tracer' antibody (which is labeled with a fluorescent dye) is added to the bulk solution. In the absence of analyte, the tracer antibody remains in solution and very little fluorescence is observed. However, upon addition of analyte, a `molecular sandwich' is formed on the waveguide, composed of: (1) the capture antibody; (2) the analyte; and (3) the tracer antibody. Once this sandwich forms, the tracer antibody is within the evanescent field and fluoresces. Fluorescence emission is detected by a charged- coupled device (CCD). Using this approach, we have developed a prototype immunosensor for the detection of human chorionic gonadotropin (hCG). This device meets our design goals and exhibits a sensitivity of 0.1 - 1 pmolar.

  7. RF window assembly comprising a ceramic disk disposed within a cylindrical waveguide which is connected to rectangular waveguides through elliptical joints

    SciTech Connect

    Tantawi, Sami G.; Dolgashev, Valery A.; Yeremian, Anahid D.

    2016-03-15

    A high-power microwave RF window is provided that includes a cylindrical waveguide, where the cylindrical waveguide includes a ceramic disk concentrically housed in a central region of the cylindrical waveguide, a first rectangular waveguide, where the first rectangular waveguide is connected by a first elliptical joint to a proximal end of the cylindrical waveguide, and a second rectangular waveguide, where the second rectangular waveguide is connected by a second elliptical joint to a distal end of the cylindrical waveguide.

  8. Hydrogen Outgassing from Lithium Hydride

    SciTech Connect

    Dinh, L N; Schildbach, M A; Smith, R A; Balazs1, B; McLean II, W

    2006-04-20

    Lithium hydride is a nuclear material with a great affinity for moisture. As a result of exposure to water vapor during machining, transportation, storage and assembly, a corrosion layer (oxide and/or hydroxide) always forms on the surface of lithium hydride resulting in the release of hydrogen gas. Thermodynamically, lithium hydride, lithium oxide and lithium hydroxide are all stable. However, lithium hydroxides formed near the lithium hydride substrate (interface hydroxide) and near the sample/vacuum interface (surface hydroxide) are much less thermally stable than their bulk counterpart. In a dry environment, the interface/surface hydroxides slowly degenerate over many years/decades at room temperature into lithium oxide, releasing water vapor and ultimately hydrogen gas through reaction of the water vapor with the lithium hydride substrate. This outgassing can potentially cause metal hydriding and/or compatibility issues elsewhere in the device. In this chapter, the morphology and the chemistry of the corrosion layer grown on lithium hydride (and in some cases, its isotopic cousin, lithium deuteride) as a result of exposure to moisture are investigated. The hydrogen outgassing processes associated with the formation and subsequent degeneration of this corrosion layer are described. Experimental techniques to measure the hydrogen outgassing kinetics from lithium hydride and methods employing the measured kinetics to predict hydrogen outgassing as a function of time and temperature are presented. Finally, practical procedures to mitigate the problem of hydrogen outgassing from lithium hydride are discussed.

  9. Electrochemical reactions of layered niobate material as novel anode for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Nakayama, Hideki; Nose, Masafumi; Nakanishi, Shinji; Iba, Hideki

    2015-08-01

    The electrochemical performances of layered niobium oxide materials were investigated for the first time as novel anode active materials for the sodium-ion battery. The layered niobate with the formula KNb3O8 was synthesized by a solid-state reaction and has been evaluated as an anode electrode by a cyclic voltammetry technique and galvanostatic charge/discharge tests. The crystal structure of KNb3O8 contains the NbO6 octahedral units and potassium alkali-metal ions interlayer to form the layered structure. KNb3O8 has a redox reaction around 1 V vs. Na/Na+ and has a reversible capacity of 104 mAh/g corresponding to the 1.7 Na+ insertion/extraction in the KNb3O8 structure. The Nb K-edge X-ray absorption near edge structure (XANES) shows that the Nb oxidation state is converted from Nb5+ to Nb4+ during the Na+ insertion stage, and reversibly recovered to Nb5+ during the Na+ extraction stage. This is the first report that the layered niobate of KNb3O8 reversibly reacts with Na+ at the potential around 1 V vs. Na/Na+ via the Nb5+/4+ redox reaction.

  10. Lithium: for harnessing renewable energy

    USGS Publications Warehouse

    Bradley, Dwight; Jaskula, Brian W.

    2014-01-01

    Lithium, which has the chemical symbol Li and an atomic number of 3, is the first metal in the periodic table. Lithium has many uses, the most prominent being in batteries for cell phones, laptops, and electric and hybrid vehicles. Worldwide sources of lithium are broken down by ore-deposit type as follows: closed-basin brines, 58%; pegmatites and related granites, 26%; lithium-enriched clays, 7%; oilfield brines, 3%; geothermal brines, 3%; and lithium-enriched zeolites, 3% (2013 statistics). There are over 39 million tons of lithium resources worldwide. Of this resource, the USGS estimates there to be approximately 13 million tons of current economically recoverable lithium reserves. To help predict where future lithium supplies might be located, USGS scientists study how and where identified resources are concentrated in the Earth’s crust, and they use that knowledge to assess the likelihood that undiscovered resources also exist.

  11. US Navy lithium cell applications

    NASA Technical Reports Server (NTRS)

    Bowers, F. M.

    1978-01-01

    Applications of lithium systems that are already in the fleet are discussed. The approach that the Navy is taking in the control of the introduction of lithium batteries into the fleet is also discussed.

  12. Lithium Inorganic Electrolyte Battery Development.

    DTIC Science & Technology

    1971-01-01

    rjp 3.2 PRISMATIC CELLS This subsection presents the results of the investigations conducted on large prismatic lithium thionyl chloride cells, both...91 5.0 PASSIVATION 5.1 INTRODUCTION Passivation in Li/SOC12 cells consists of the surface reaction of lithium directly with thionyl chloride to...produce a film of lithium chloride (LiCI). This film prevents the complete and rapid reaction of lithium and thionyl chloride at moderate temperatures. On

  13. Scalar Product in the Space of Waveguide Modes of an Open Planar Waveguide

    NASA Astrophysics Data System (ADS)

    Sevastianov, A. L.; Sevastianov, L. A.; Tiutiunnik, A. A.; Nikolaev, N. E.

    2016-02-01

    To implement the method of adiabatic waveguide modes for modeling the propagation of polarized monochromatic electromagnetic radiation in irregular integrated optics structures it is necessary to expand the desired solution in basic adiabatic waveguide modes. This expansion requires the use of the scalar product in the space of waveguide vector fields of integrated optics waveguide. This work solves the first stage of this problem - the construction of the scalar product in the space of vector solutions of the eigenmode problem (classical and generalized) waveguide modes of an open planar waveguide. In constructing the mentioned sesquilinear form, we used the Lorentz reciprocity principle of waveguide modes and tensor form of the Ostrogradsky-Gauss theorem.

  14. Waveguide tapering for beam-width control in a waveguide transducer.

    PubMed

    Kwon, Young Eui; Jeon, Hyun Joong; Kim, Hoe Woong; Kim, Yoon Young

    2014-03-01

    In a waveguide transducer that transmits an ultrasonic wave through a waveguide unit to a test structure, it is most preferred to send a non-dispersive ultrasonic wave of a narrow beam width. However, there is an unresolved conflict between the generation of the non- or less-dispersive wave and the transmission of a narrow-beam wave into a test structure. Among others, the thickness of the waveguide unit in a waveguide transducer is the key variable determining these two conflicting criteria, but the use of a uniformly-thick waveguide of any thickness cannot fulfill the two conflicting criteria simultaneously. In this study, we propose a specially-engineered tapered waveguide unit for the simultaneous satisfaction. An excitation unit is installed at the end of the thin region of the tapered waveguide and generates only the lowest non-dispersive shear-horizontal wave. Then the generated wave propagates through the tapered region of the waveguide unit and reaches the thick region of the waveguide with insignificant mode conversion to higher modes. If the tapered waveguide is used, the surviving lowest mode in the thick region of the waveguide is shown to carry most of the transmitted power and is finally propagated into a test structure. Because the beam size of the propagated wave and the thickness of the contacting waveguide region are inversely related, the thick contacting region of the tapered waveguide ensures narrow beam width. Numerical and experimental investigations were performed to check the effectiveness of the proposed waveguide-tapering approach.

  15. Cooling Waveguide Flanges in Microwave Transmitters

    NASA Technical Reports Server (NTRS)

    Chen, B. C.; Hartop, R. W.

    1984-01-01

    Flang appendage circulates coolant for conductive heat removal. Flange appendage bore accomodates coolant tube. O-ring surrounds bore; when adjacent waveguide sections are bolted together, continuous conduit is formed for coolant. Pressure release groove in modified flange prevents coolant from entering waveguide should O'ring seal fail.

  16. Planar fluoride waveguides for amplifiers and lasers

    SciTech Connect

    Grishutkina, T E; Doroshenko, M E; Karasik, A Ya; Konyushkin, V A; Konyushkin, D V; Nakladov, A N; Osiko, V V; Tsvetkov, V B

    2015-08-31

    We have produced planar optical waveguides having a crystalline CaF{sub 2} – YF{sub 3} – NdF{sub 3} mixed yttrofluorite core and two reflective claddings in order to improve waveguide excitation efficiency. Under diode pumping, lasing has been achieved at a wavelength of 1064 nm with a slope efficiency near 15%. (lasers)

  17. Waveguide Transition for Submillimeter-Wave MMICs

    NASA Technical Reports Server (NTRS)

    Leong, Kevin M.; Deal, William R.; Radisic, Vesna; Mei, Xiaobing; Uyeda, Jansen; Lai, Richard; Fung, King Man; Gaier, Todd C.

    2009-01-01

    An integrated waveguide-to-MMIC (monolithic microwave integrated circuit) chip operating in the 300-GHz range is designed to operate well on high-permittivity semiconductor substrates typical for an MMIC amplifier, and allows a wider MMIC substrate to be used, enabling integration with larger MMICs (power amplifiers). The waveguide-to- CBCPW (conductor-backed coplanar waveguide) transition topology is based on an integrated dipole placed in the E-plane of the waveguide module. It demonstrates low loss and good impedance matching. Measurement and simulation demonstrate that the loss of the transition and waveguide loss is less than 1-dB over a 340-to-380-GHz bandwidth. A transition is inserted along the propagation direction of the waveguide. This transition uses a planar dipole aligned with the maximum E-field of the TE10 waveguide mode as an inter face between the waveguide and the MMIC. Mode conversion between the coplanar striplines (CPS) that feed the dipole and the CBCPW transmission line is accomplished using a simple air-bridge structure. The bottom side ground plane is truncated at the same reference as the top-side ground plane, leaving the end of the MMIC suspended in air.

  18. High temperature pressure coupled ultrasonic waveguide

    DOEpatents

    Caines, Michael J.

    1983-01-01

    A pressure coupled ultrasonic waveguide is provided to which one end may be attached a transducer and at the other end a high temperature material for continuous ultrasonic testing of the material. The ultrasonic signal is coupled from the waveguide into the material through a thin, dry copper foil.

  19. Capillary waveguide optrodes for Medical applications

    NASA Astrophysics Data System (ADS)

    Kieslinger, Dietmar; Weigl, Bernhard H.; Draxler, Sonja; Lippitsch, Max E.

    1997-01-01

    Glass capillaries with a chemically sensitive coating on the inner surface are used as optical sensors for medical diagnostics. The capillary simultaneously serves as a sample compartment, a sensor element, and an inhomogeneous optical waveguide. Different optical setups have been investigated and compared regarding its waveguiding properties.

  20. Reversibility of anodic lithium in rechargeable lithium-oxygen batteries.

    PubMed

    Shui, Jiang-Lan; Okasinski, John S; Kenesei, Peter; Dobbs, Howard A; Zhao, Dan; Almer, Jonathan D; Liu, Di-Jia

    2013-01-01

    Non-aqueous lithium-air batteries represent the next-generation energy storage devices with very high theoretical capacity. The benefit of lithium-air batteries is based on the assumption that the anodic lithium is completely reversible during the discharge-charge process. Here we report our investigation on the reversibility of the anodic lithium inside of an operating lithium-air battery using spatially and temporally resolved synchrotron X-ray diffraction and three-dimensional micro-tomography technique. A combined electrochemical process is found, consisting of a partial recovery of lithium metal during the charging cycle and a constant accumulation of lithium hydroxide under both charging and discharging conditions. A lithium hydroxide layer forms on the anode separating the lithium metal from the separator. However, numerous microscopic 'tunnels' are also found within the hydroxide layer that provide a pathway to connect the metallic lithium with the electrolyte, enabling sustained ion-transport and battery operation until the total consumption of lithium.

  1. On-chip plasmonic waveguide optical waveplate

    PubMed Central

    Gao, Linfei; Huo, Yijie; Zang, Kai; Paik, Seonghyun; Chen, Yusi; Harris, James S.; Zhou, Zhiping

    2015-01-01

    Polarization manipulation is essential in almost every photonic system ranging from telecommunications to bio-sensing to quantum information. This is traditionally achieved using bulk waveplates. With the developing trend of photonic systems towards integration and miniaturization, the need for an on-chip waveguide type waveplate becomes extremely urgent. However, this is very challenging using conventional dielectric waveguides, which usually require complex 3D geometries to alter the waveguide symmetry and are also difficult to create an arbitrary optical axis. Recently, a waveguide waveplate was realized using femtosecond laser writing, but the device length is in millimeter range. Here, for the first time we propose and experimentally demonstrate an ultracompact, on-chip waveplate using an asymmetric hybrid plasmonic waveguide to create an arbitrary optical axis. The device is only in several microns length and produced in a flexible integratable IC compatible format, thus opening up the potential for integration into a broad range of systems. PMID:26507563

  2. Light propagation in periodically modulated complex waveguides

    NASA Astrophysics Data System (ADS)

    Nixon, Sean; Yang, Jianke

    2015-03-01

    Light propagation in optical waveguides with periodically modulated index of refraction and alternating gain and loss are investigated for linear and nonlinear systems. Based on a multiscale perturbation analysis, it is shown that for many non-parity-time- (PT -) symmetric waveguides, their linear spectrum is partially complex; thus light exponentially grows or decays upon propagation, and this growth or decay is not altered by nonlinearity. However, several classes of non-PT -symmetric waveguides are also identified to possess all-real linear spectrum. For PT -symmetric waveguides, phase transition is predicted analytically. In the nonlinear regime longitudinally periodic and transversely quasilocalized modes are found for PT -symmetric waveguides both above and below phase transition. These nonlinear modes are stable under evolution and can develop from initially weak initial conditions.

  3. Hybrid grapheme plasmonic waveguide modulators

    NASA Astrophysics Data System (ADS)

    Ansell, D.; Thackray, B. D.; Aznakayeva, D. E.; Thomas, P.; Auton, G. H.; Marshall, O. P.; Rodriguez, F. J.; Radko, I. P.; Han, Z.; Bozhevolnyi, S. I.; Grigorenko, A. N.

    2016-03-01

    The unique optical and electronic properties of graphene allow one to realize active optical devices. While several types of graphene-based photonic modulators have already been demonstrated, the potential of combining the versatility of graphene with sub-wavelength field confinement of plasmonic/metallic structures is not fully realized. Here we report fabrication and study of hybrid graphene-plasmonic modulators. We consider several types of modulators and identify the most promising one for light modulation at telecom and near-infrared. Our proof-of-concept results pave the way towards on-chip realization of efficient graphene-based active plasmonic waveguide devices for optical communications.

  4. Lithium Dinitramide as an Additive in Lithium Power Cells

    NASA Technical Reports Server (NTRS)

    Gorkovenko, Alexander A.

    2007-01-01

    Lithium dinitramide, LiN(NO2)2 has shown promise as an additive to nonaqueous electrolytes in rechargeable and non-rechargeable lithium-ion-based electrochemical power cells. Such non-aqueous electrolytes consist of lithium salts dissolved in mixtures of organic ethers, esters, carbonates, or acetals. The benefits of adding lithium dinitramide (which is also a lithium salt) include lower irreversible loss of capacity on the first charge/discharge cycle, higher cycle life, lower self-discharge, greater flexibility in selection of electrolyte solvents, and greater charge capacity. The need for a suitable electrolyte additive arises as follows: The metallic lithium in the anode of a lithium-ion-based power cell is so highly reactive that in addition to the desired main electrochemical reaction, it engages in side reactions that cause formation of resistive films and dendrites, which degrade performance as quantified in terms of charge capacity, cycle life, shelf life, first-cycle irreversible capacity loss, specific power, and specific energy. The incidence of side reactions can be reduced through the formation of a solid-electrolyte interface (SEI) a thin film that prevents direct contact between the lithium anode material and the electrolyte. Ideally, an SEI should chemically protect the anode and the electrolyte from each other while exhibiting high conductivity for lithium ions and little or no conductivity for electrons. A suitable additive can act as an SEI promoter. Heretofore, most SEI promotion was thought to derive from organic molecules in electrolyte solutions. In contrast, lithium dinitramide is inorganic. Dinitramide compounds are known as oxidizers in rocket-fuel chemistry and until now, were not known as SEI promoters in battery chemistry. Although the exact reason for the improvement afforded by the addition of lithium dinitramide is not clear, it has been hypothesized that lithium dinitramide competes with other electrolyte constituents to react with

  5. Lithium Ion Batteries

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Lithium ion batteries, which use a new battery chemistry, are being developed under cooperative agreements between Lockheed Martin, Ultralife Battery, and the NASA Lewis Research Center. The unit cells are made in flat (prismatic) shapes that can be connected in series and parallel to achieve desired voltages and capacities. These batteries will soon be marketed to commercial original-equipment manufacturers and thereafter will be available for military and space use. Current NiCd batteries offer about 35 W-hr/kg compared with 110 W-hr/kg for current lithium ion batteries. Our ultimate target for these batteries is 200 W-hr/kg.

  6. Investigation of Lithium Ion Storage

    NASA Technical Reports Server (NTRS)

    Lee, Leonine; Rao, Gopalkrishna M.

    1999-01-01

    NASA/GSFC is interested in flying lithium ion cells for geosynchronous earth orbit (GEO) satellites. To determine the preferred solstice storage conditions for the lithium ion chemistry, we have been studying either a constant current storage with a maximum voltage clamp or storage with only a voltage clamp. The cells used for this study are two 4Ah SAFT cylindrical lithium ion cells, two 1.5Ah Wilson Great Batch lithium ion cells, and one 8Ah Lithium Technology lithium polymer cell. In each pair, one cell is clamped at 4V, and the other is trickle charged at C/500 with a 4.lV clamp. The Lithium Technology cell is only undergoing voltage clamped storage testing. After each storage period the cells are subjected to a capacity test (C/2 discharge, C/10 charge) and a charge retention test at room temperature. Results after 4 weeks and 8 weeks of storage testing will be presented here.

  7. Theoretical Study of Monolayer and Double-Layer Waveguide Love Wave Sensors for Achieving High Sensitivity

    PubMed Central

    Li, Shuangming; Wan, Ying; Fan, Chunhai; Su, Yan

    2017-01-01

    Love wave sensors have been widely used for sensing applications. In this work, we introduce the theoretical analysis of the monolayer and double-layer waveguide Love wave sensors. The velocity, particle displacement and energy distribution of Love waves were analyzed. Using the variations of the energy repartition, the sensitivity coefficients of Love wave sensors were calculated. To achieve a higher sensitivity coefficient, a thin gold layer was added as the second waveguide on top of the silicon dioxide (SiO2) waveguide–based, 36 degree–rotated, Y-cut, X-propagating lithium tantalate (36° YX LiTaO3) Love wave sensor. The Love wave velocity was significantly reduced by the added gold layer, and the flow of wave energy into the waveguide layer from the substrate was enhanced. By using the double-layer structure, almost a 72-fold enhancement in the sensitivity coefficient was achieved compared to the monolayer structure. Additionally, the thickness of the SiO2 layer was also reduced with the application of the gold layer, resulting in easier device fabrication. This study allows for the possibility of designing and realizing robust Love wave sensors with high sensitivity and a low limit of detection. PMID:28327504

  8. Ultralow loss cavities and waveguides scattering loss cancellation

    DOEpatents

    Rakich, Peter T

    2014-01-07

    A waveguide system includes a first waveguide having surface roughness along at least one surface and a second waveguide substantially identical to the first waveguide and having substantially identical surface roughness along a corresponding side. The first and second waveguides are separated from each other by a predermined distance and are configured to receive respective first and second light signals having antisymmetric modes. The predetermined distance between the first and second waveguide tends to cause cancellation of at least far-field polarization radiation emanating from the first and second waveguides and resulting from surface roughness.

  9. 77 FR 28259 - Mailings of Lithium Batteries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-14

    ... for mailpieces containing lithium metal or lithium-ion cells or batteries and applies regardless of...'' instead of ``lithium content'' for secondary lithium-ion batteries when describing maximum quantity limits...-ion (Rechargeable) Cells and Batteries Small consumer-type lithium-ion cells and batteries like...

  10. Enhanced Photocatalytic Activity of TiO2 - niobate nanosheet composites

    SciTech Connect

    Liu, Jian; Nichols, Eric; Howe, Jane Y; Misture, S T

    2013-01-01

    Protonized niobate nanosheets H1.8Bi0.2CaNaNb3O10 were synthesized using a new, organic-free simultaneous ion-exchange and exfoliation process from the Aurivillius phase Bi2CaNaNb3O12. Nanosheet/TiO2 composites were prepared by thermal treatment of physical mixtures of commercially available anatase TiO2 and the nanosheet suspension. Methylene blue dye degradation studies for the composite show a clear correlation between the methylene blue surface adsorption and the degradation rate. The composite exhibits strongly enhanced photocatalytic activity as the calcination temperature increases, suggesting the possibility of the charge transfer at BCNN-TiO2 interface and the existence of Nb5+ and O2- acid-base pairs. Both phenomena are attributed to the processing approach, which includes topochemcial dehydration of the BCNN nanosheets during heat treatment.

  11. Potassium Niobate Nanolamina: A Promising Adsorbent for Entrapment of Radioactive Cations from Water

    PubMed Central

    Sun, Jin; Yang, Dongjiang; Sun, Cuihua; Liu, Long; Yang, Shuanglei; (Alec) Jia, Yi; Cai, Rongsheng; Yao, Xiangdong

    2014-01-01

    Processing and managing radioactive waste is a great challenge worldwide as it is extremely difficult and costly; the radioactive species, cations or anions, leaked into the environment are a serious threat to the health of present and future generations. We report layered potassium niobate (K4Nb6O17) nanolamina as adsorbent to remove toxic Sr2+, Ba2+ and Cs+ cations from wastewater. The results show that K4Nb6O17 nanolamina can permanently confine the toxic cations within the interlayer spacing via a considerable deformation of the metastable layered structure during the ion exchange process. At the same time, the nanolaminar adsorbent exhibits prompt adsorption kinetics, high adsorption capacity and selectivity, and superior acid resistance. These merits make it be a promising material as ion exchanger for the removal of radioactive cations from wastewater. PMID:25472721

  12. Laser irradiation in Nd{sup 3+} doped strontium barium niobate glass

    SciTech Connect

    Haro-Gonzalez, P.; Martin, I. R.; Arbelo-Jorge, E.; Gonzalez-Perez, S.; Caceres, J. M.; Nunez, P.

    2008-07-01

    A local nanocrystalline formation in a neodymium doped strontium barium niobate (SBN) glass has been obtained under argon laser irradiation. The intense emission around 880 nm, originated from the {sup 4}F{sub 3/2} ({sup 4}F{sub 5/2}) thermalized level when the glass structure changes to a glass ceramic structure due to the irradiation of the laser beam, has been studied. The intensities and lifetimes change from this level inside and outside the irradiated area made by the laser excitation. They have been analyzed and demonstrated that the desvitrification process has been successfully achieved. These results confirm that nanocrystals of SBN have been created by the laser action confirming that the transition from glass to glass ceramic has been completed. These results are in agreement with the emission properties of nanocrystals of the bulk glass ceramic sample. The present study also suggests that the SBN nanocrystal has a potential application as temperature detector.

  13. Single potassium niobate nano/microsized particles as local mechano-optical Brownian probes

    NASA Astrophysics Data System (ADS)

    Mor, Flavio M.; Sienkiewicz, Andrzej; Magrez, Arnaud; Forró, László; Jeney, Sylvia

    2016-03-01

    Perovskite alkaline niobates, due to their strong nonlinear optical properties, including birefringence and the capability to produce second-harmonic generation (SHG) signals, attract a lot of attention as potential candidates for applications as local nano/microsized mechano-optical probes. Here, we report on an implementation of photonic force microscopy (PFM) to explore the Brownian motion and optical trappability of monocrystalline potassium niobate (KNbO3) nano/microsized particles having sizes within the range of 50 to 750 nm. In particular, we exploit the anisotropic translational diffusive regime of the Brownian motion to quantify thermal fluctuations and optical forces of singly-trapped KNbO3 particles within the optical trapping volume of a PFM microscope. We also show that, under near-infrared (NIR) excitation of the highly focused laser beam of the PFM microscope, a single optically-trapped KNbO3 particle reveals a strong SHG signal manifested by a narrow peak (λem = 532 nm) at half the excitation wavelength (λex = 1064 nm). Moreover, we demonstrate that the thus induced SHG emission can be used as a local light source that is capable of optically exciting molecules of an organic dye, Rose Bengal (RB), which adhere to the particle surface, through the mechanism of luminescence energy transfer (LET).Perovskite alkaline niobates, due to their strong nonlinear optical properties, including birefringence and the capability to produce second-harmonic generation (SHG) signals, attract a lot of attention as potential candidates for applications as local nano/microsized mechano-optical probes. Here, we report on an implementation of photonic force microscopy (PFM) to explore the Brownian motion and optical trappability of monocrystalline potassium niobate (KNbO3) nano/microsized particles having sizes within the range of 50 to 750 nm. In particular, we exploit the anisotropic translational diffusive regime of the Brownian motion to quantify thermal

  14. Probing local structure of pyrochlore lead zinc niobate with synchrotron x-ray absorption spectroscopy technique

    NASA Astrophysics Data System (ADS)

    Kanchiang, Kanokwan; Pramchu, Sittichain; Yimnirun, Rattikorn; Pakawanit, Phakkhananan; Ananta, Supon; Laosiritaworn, Yongyut

    2013-08-01

    Local structure of lead zinc niobate (PZN) ceramic, synthesized via B-site oxide precursor route in atmospheric pressure, was investigated using synchrotron x-ray absorption spectroscopy (XAS) technique. The x-ray absorption near-edge structure (XANES) simulation was first carried out. The XANES simulation results indicate that the PZN ceramic is in pyrochlore phase having Zn2+ substituted on Nb5+ site. Afterwards, the extended x-ray absorption fine structure (EXAFS) analysis was performed to extract the bond length information between Zn2+ and its neighboring atoms. From the EXAFS fitting, the bond length between Zn2+ and Pb2+ in the pyrochlore phase was found to be longer than the previously reported bond length in the perovskite phase. Further, with the radial distribution information of Zn2+'s neighboring atoms, the formation energies along the precursor-to-pyrochlore and precursor-to-perovskite reaction paths were calculated using the density functional theory (DFT). The calculated results show that the formation energy of the perovskite phase is noticeably higher than that of the pyrochlore phase, which is influenced by the presence of energetic Pb2+ lone pair, as the perovskite phase has shorter Zn2+ to Pb2+ bonding. This therefore suggests the steric hindrance of Pb2+ lone pair and the mutual interactions between Pb2+ lone pair and Zn2+ are main causes of the instability of lead zinc niobate in the perovskite structure and confirm the efficacy of XAS and DFT analysis in revealing local structural details of complex pyrochlore materials.

  15. Waveguide-Based Biosensors for Pathogen Detection

    PubMed Central

    Mukundan, Harshini; Anderson, Aaron S.; Grace, W. Kevin; Grace, Karen M.; Hartman, Nile; Martinez, Jennifer S.; Swanson, Basil I.

    2009-01-01

    Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic) are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, such as a substrate and the media to be sensed. This arrangement allows coupled light to propagate through the high refractive index waveguide by total internal reflection and generates an electromagnetic wave—the evanescent field—whose amplitude decreases exponentially as the distance from the surface increases. Excitation of fluorophores within the evanescent wave allows for sensitive detection while minimizing background fluorescence from complex, “dirty” biological samples. In this review, we will describe the basic principles, advantages and disadvantages of planar optical waveguide-based biodetection technologies. This discussion will include already commercialized technologies (e.g., Corning’s EPIC® Ô, SRU Biosystems’ BIND™, Zeptosense®, etc.) and new technologies that are under research and development. We will also review differing assay approaches for the detection of various biomolecules, as well as the thin-film coatings that are often required for waveguide functionalization and effective detection. Finally, we will discuss reverse-symmetry waveguides, resonant waveguide grating sensors and metal-clad leaky waveguides as alternative signal transducers in optical biosensing. PMID:22346727

  16. Plasmonic antennas hybridized with dielectric waveguides.

    PubMed

    Bernal Arango, Felipe; Kwadrin, Andrej; Koenderink, A Femius

    2012-11-27

    For the purpose of using plasmonics in an integrated scheme where single emitters can be probed efficiently, we experimentally and theoretically study the scattering properties of single nanorod gold antennas as well as antenna arrays placed on one-dimensional dielectric silicon nitride waveguides. Using real space and Fourier microscopy correlated with waveguide transmission measurements, we quantify the spectral properties, absolute strength, and directivity of scattering. The scattering processes can be well understood in the framework of the physics of dipolar objects placed on a planar layered environment with a waveguiding layer. We use the single plasmonic structures on top of the waveguide as dipolar building blocks for new types of antennas where the waveguide enhances the coupling between antenna elements. We report on waveguide hybridized Yagi-Uda antennas which show directionality in out-coupling of guided modes as well as directionality for in-coupling into the waveguide of localized excitations positioned at the feed element. These measurements together with simulations demonstrate that this system is ideal as a platform for plasmon quantum optics schemes as well as for fluorescence lab-on-chip applications.

  17. Optofluidic waveguides: I. Concepts and implementations

    PubMed Central

    Schmidt, Holger; Hawkins, Aaron R.

    2011-01-01

    We review recent developments and current status of liquid-core optical waveguides in optofluidics with emphasis on suitability for creating fully planar optofluidic labs-on-a-chip. In this first of two contributions, we give an overview of the different waveguide types that are being considered for effectively combining micro and nanofluidics with integrated optics. The large number of approaches is separated into conventional index-guided waveguides and more recent implementations using wave interference. The underlying principle for waveguiding and the current status are described for each type. We then focus on reviewing recent work on microfabricated liquid-core antiresonant reflecting optical (ARROW) waveguides, including the development of intersecting 2D waveguide networks and optical fluorescence and Raman detection with planar beam geometry. Single molecule detection capability and addition of electrical control for electrokinetic manipulation and analysis of single bioparticles are demonstrated. The demonstrated performance of liquid-core ARROWs is representative of the potential of integrated waveguides for on-chip detection with ultrahigh sensitivity, and points the way towards the next generation of high-performance, low-cost and portable biomedical instruments. PMID:21442048

  18. Lithium disulfide battery

    DOEpatents

    Kaun, Thomas D.

    1988-01-01

    A negative electrode limited secondary electrochemical cell having dense FeS.sub.2 positive electrode operating exclusively on the upper plateau, a Li alloy negative electrode and a suitable lithium-containing electrolyte. The electrolyte preferably is 25 mole percent LiCl, 38 mole percent LiBr and 37 mole percent KBr. The cell may be operated isothermally.

  19. Lithium ion conducting electrolytes

    DOEpatents

    Angell, C.A.; Liu, C.

    1996-04-09

    A liquid, predominantly lithium-conducting, ionic electrolyte is described having exceptionally high conductivity at temperatures of 100 C or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH{sub 3}CN), succinnonitrile (CH{sub 2}CN){sub 2}, and tetraglyme (CH{sub 3}--O--CH{sub 2}--CH{sub 2}--O--){sub 2} (or like solvents) solvated to a Mg{sup +2} cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100 C conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone. 2 figs.

  20. Lithium ion conducting electrolytes

    DOEpatents

    Angell, C. Austen; Liu, Changle

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte having exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH.sub.3 CN) succinnonitrile (CH.sub.2 CN).sub.2, and tetraglyme (CH.sub.3 --O--CH.sub.2 --CH.sub.2 --O--).sub.2 (or like solvents) solvated to a Mg.sup.+2 cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100.degree. C. conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone.

  1. Lithium battery discharge tests

    NASA Technical Reports Server (NTRS)

    Johnson, C. J.

    1980-01-01

    The long term discharge of a variety of lithium cells was characterized and the susceptibility of the cells to chemical variation during the slow discharge was tested. A shunt resistor was set across the terminals to monitor the voltage as a function of time. Failures were identified by premature voltage drops.

  2. Optical waveguide materials, structures, and dispersion modulation

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Liu, Jiaming; Lin, Jian; Li, Wenxiu; Xue, Xia; Huang, Anping; Xiao, Zhisong

    2016-11-01

    Optical waveguide is used in most integrated optic devices to confine and guide light in higher refractive index channels. The structures and materials of slot waveguides are reviewed in this paper. Coupled resonator optical waveguides (CROWs) can be used for a rotation sensor with compact size, low power consumption and low cost. The loss determines the ultimate sensitivity of CROW gyros. Resonator-based optical gyroscope's sensitivity for measuring rotation is enhanced via using the anomalous dispersion characteristic of superluminal light propagation, which can be also generated by using passive optical resonators.

  3. Waveguide optical isolator: a new design.

    PubMed

    Ando, K

    1991-03-20

    A new design of a thin film waveguide optical isolator is described. It is composed of a nonreciprocal mode converter by the Faraday effect, a reciprocal mode converter by the Cotton-Mouton effect, an integrated mirror, and TE-mode selectors. Its mode transfer matrices are derived. Numerical calculations show that wider tolerances of the film parameters and smaller dimensions are obtained compared with the ordinary tandem type waveguide isolators without the integrated mirror. This structure is free of the problem of the localized control of the directions of the magnetization, which has been required for the ordinary tandem type waveguide isolator.

  4. Waveguide grating mirror for laser resonators

    NASA Astrophysics Data System (ADS)

    Rabady, Rabi Ibrahim

    Improved beam quality for semiconductor lasers has been a challenging problem since laser invention. The approach proposed in this thesis for beam improvement is based on zero-order anomalies in the reflectance spectra of periodically corrugated waveguides, which is the waveguide analogy of the well-known Wood anomalies in diffraction spectra of metallic gratings. The proposed investigation include developing a high-quality and reliable technologies for optical waveguides, holographic-grating, and optical resonant filters. Applications of this research include high-power and high-brightness vertical-cavity surface-emitting lasers (VCSELs), large area lasers, and laser arrays for optical communications, lidars, and industrial material processing.

  5. Waveguide-based optical chemical sensor

    SciTech Connect

    Grace, Karen M.; Swanson, Basil I.; Honkanen, Seppo

    2007-03-13

    The invention provides an apparatus and method for highly selective and sensitive chemical sensing. Two modes of laser light are transmitted through a waveguide, refracted by a thin film host reagent coating on the waveguide, and analyzed in a phase sensitive detector for changes in effective refractive index. Sensor specificity is based on the particular species selective thin films of host reagents which are attached to the surface of the planar optical waveguide. The thin film of host reagents refracts laser light at different refractive indices according to what species are forming inclusion complexes with the host reagents.

  6. Optical planar waveguide for cell counting

    NASA Astrophysics Data System (ADS)

    LeBlanc, John; Mueller, Andrew J.; Prinz, Adrian; Butte, Manish J.

    2012-01-01

    Low cost counting of cells has medical applications in screening, military medicine, disaster medicine, and rural healthcare. In this report, we present a shallow, buried, planar waveguide fabricated by potassium ion exchange in glass that enables low-cost and rapid counting of metal-tagged objects that lie in the evanescent field of the waveguide. Laser light transmitted through the waveguide was attenuated proportionately to the presence of metal-coated microstructures fabricated from photoresist. This technology enables the low-cost enumeration of cells from blood, urine, or other biofluids.

  7. Guided modes of elliptical metamaterial waveguides

    SciTech Connect

    Halterman, Klaus; Feng, Simin; Overfelt, P. L.

    2007-07-15

    The propagation of guided electromagnetic waves in open elliptical metamaterial waveguide structures is investigated. The waveguide contains a negative-index media core, where the permittivity {epsilon} and permeability {mu} are negative over a given bandwidth. The allowed mode spectrum for these structures is numerically calculated by solving a dispersion relation that is expressed in terms of Mathieu functions. By probing certain regions of parameter space, we find the possibility exists to have extremely localized waves that transmit along the surface of the waveguide.

  8. Efficient blue light generation using periodically poled stoichiometric lithium tantalate via resonant frequency doubling

    NASA Astrophysics Data System (ADS)

    Khademian, Ali; Jadhav, Shilpa; Shiner, David

    2014-05-01

    Convenient high power blue diode lasers with single frequency operation are still under developments and are not as well developed and cost effective as IR laser sources. Harmonic generation of IR lasers provide a viable alternative source of blue and UV light. Magnesium oxide doped periodically poled Stoichiometric Lithium Tantalate (PPMgO:SLT) has been reported to have the lowest blue, IR and blue induced IR absorption (BLIIRA) among ferroelectric crystals such as Lithium Niobate (PPLN) and Potassium Titanyl Phosphate (PPKTP). All these properties, along with higher thermal conductivity, make this crystal an excellent candidate for efficient blue light generation using second harmonic generation (SHG) in a resonant buildup cavity. Efficient resonant doubling is very sensitive to various cavity and crystal loss mechanisms. Recently we obtained 400 mW of blue light at 486 nm with net conversion efficiency of 77% using a 515 mW fiber grating stabilized IR source. Sources of conversion loss have been identified and evaluated with various methods in our investigation. These include reflection, scattering, absorption, and polarization rotation of IR light in the crystal, as well as mode mismatching and spherical aberration due to focusing lenses. The locking and electronic control functions of the cavity are automated using an internally mounted single chip microcontroller with embedded DSP (digital signal processor). Work is supported by NSF grant.

  9. Waveguide silicon nitride grating coupler

    NASA Astrophysics Data System (ADS)

    Litvik, Jan; Dolnak, Ivan; Dado, Milan

    2016-12-01

    Grating couplers are one of the most used elements for coupling of light between optical fibers and photonic integrated components. Silicon-on-insulator platform provides strong confinement of light and allows high integration. In this work, using simulations we have designed a broadband silicon nitride surface grating coupler. The Fourier-eigenmode expansion and finite difference time domain methods are utilized in design optimization of grating coupler structure. The fully, single etch step grating coupler is based on a standard silicon-on-insulator wafer with 0.55 μm waveguide Si3N4 layer. The optimized structure at 1550 nm wavelength yields a peak coupling efficiency -2.6635 dB (54.16%) with a 1-dB bandwidth up to 80 nm. It is promising way for low-cost fabrication using complementary metal-oxide- semiconductor fabrication process.

  10. Color sorting by retinal waveguides.

    PubMed

    Labin, Amichai M; Ribak, Erez N

    2014-12-29

    Light is being detected by the two distinct types of photoreceptors in the human retina: cones and rods. Before light arrives at the photoreceptors, it must traverse the whole retina, along its array of higher-index Müller cells serving as natural waveguides. Here we analyze this optical process of light propagation through Müller cells by two independent optical methods: numerical beam propagation and analytical modal analysis. We show that the structure and refractive index profile of the Müller cells create a unique spatio-spectral distribution of light. This distribution corresponds to the positions and spectral sensitivities of both cones and rods to improve their light absorption.

  11. Slotted antenna waveguide plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor)

    2007-01-01

    A high density plasma generated by microwave injection using a windowless electrodeless rectangular slotted antenna waveguide plasma source has been demonstrated. Plasma probe measurements indicate that the source could be applicable for low power ion thruster applications, ion implantation, and related applications. This slotted antenna plasma source invention operates on the principle of electron cyclotron resonance (ECR). It employs no window and it is completely electrodeless and therefore its operation lifetime is long, being limited only by either the microwave generator itself or charged particle extraction grids if used. The high density plasma source can also be used to extract an electron beam that can be used as a plasma cathode neutralizer for ion source beam neutralization applications.

  12. Waveguides having patterned, flattened modes

    SciTech Connect

    Messerly, Michael J.; Pax, Paul H.; Dawson, Jay W.

    2015-10-27

    Field-flattening strands may be added to and arbitrarily positioned within a field-flattening shell to create a waveguide that supports a patterned, flattened mode. Patterning does not alter the effective index or flattened nature of the mode, but does alter the characteristics of other modes. Compared to a telecom fiber, a hexagonal pattern of strands allows for a three-fold increase in the flattened mode's area without reducing the separation between its effective index and that of its bend-coupled mode. Hexagonal strand and shell elements prove to be a reasonable approximation, and, thus, to be of practical benefit vis-a-vis fabrication, to those of circular cross section. Patterned flattened modes offer a new and valuable path to power scaling.

  13. Multimode waveguide based directional coupler

    NASA Astrophysics Data System (ADS)

    Ahmed, Rajib; Rifat, Ahmmed A.; Sabouri, Aydin; Al-Qattan, Bader; Essa, Khamis; Butt, Haider

    2016-07-01

    The Silicon-on-Insulator (SOI) based platform overcomes limitations of the previous copper and fiber based technologies. Due to its high index difference, SOI waveguide (WG) and directional couplers (DC) are widely used for high speed optical networks and hybrid Electro-Optical inter-connections; TE00-TE01, TE00-TE00 and TM00-TM00 SOI direction couplers are designed with symmetrical and asymmetrical configurations to couple with TE00, TE01 and TM00 in a multi-mode semi-triangular ring-resonator configuration which will be applicable for multi-analyte sensing. Couplers are designed with effective index method and their structural parameters are optimized with consideration to coupler length, wavelength and polarization dependence. Lastly, performance of the couplers are analyzed in terms of cross-talk, mode overlap factor, coupling length and coupling efficiency.

  14. Photo-induced morphological winding and unwinding motion of nanoscrolls composed of niobate nanosheets with a polyfluoroalkyl azobenzene derivative

    NASA Astrophysics Data System (ADS)

    Nabetani, Yu; Takamura, Hazuki; Uchikoshi, Akino; Hassan, Syed Zahid; Shimada, Tetsuya; Takagi, Shinsuke; Tachibana, Hiroshi; Masui, Dai; Tong, Zhiwei; Inoue, Haruo

    2016-06-01

    Photo-responsive nanoscrolls can be successfully fabricated by mixing a polyfluoroalkyl azobenzene derivative and a niobate nanosheet, which is exfoliated from potassium hexaniobate. In this study, we have found that the photo-responsive nanoscroll shows a morphological motion of winding and unwinding, which is basically due to the nanosheet sliding within the nanoscroll, by efficient photo-isomerization reactions of the intercalated azobenzene in addition to the interlayer distance change of the nanoscrolls. The relative nanosheet sliding of the nanoscroll is estimated to be ca. 280 nm from the AFM morphology analysis. The distance of the sliding motion is over 20 times that of the averaged nanosheet sliding in the azobenzene/niobate hybrid film reported previously. Photo-responsive nanoscrolls can be expected to be novel photo-activated actuators and artificial muscle model materials.Photo-responsive nanoscrolls can be successfully fabricated by mixing a polyfluoroalkyl azobenzene derivative and a niobate nanosheet, which is exfoliated from potassium hexaniobate. In this study, we have found that the photo-responsive nanoscroll shows a morphological motion of winding and unwinding, which is basically due to the nanosheet sliding within the nanoscroll, by efficient photo-isomerization reactions of the intercalated azobenzene in addition to the interlayer distance change of the nanoscrolls. The relative nanosheet sliding of the nanoscroll is estimated to be ca. 280 nm from the AFM morphology analysis. The distance of the sliding motion is over 20 times that of the averaged nanosheet sliding in the azobenzene/niobate hybrid film reported previously. Photo-responsive nanoscrolls can be expected to be novel photo-activated actuators and artificial muscle model materials. Electronic supplementary information (ESI) available: Fig. S1. Photo-isomerization reaction of nanoscrolls. See DOI: 10.1039/c6nr02177h

  15. Sputter deposition of lithium silicate - lithium phosphate amorphous electrolytes

    SciTech Connect

    Dudney, N.J.; Bates, J.B.; Luck, C.F. ); Robertson, J.D. . Dept. of Chemistry)

    1991-01-01

    Thin films of an amorphous lithium-conducting electrolyte were deposited by rf magnetron sputtering of ceramic targets containing Li{sub 4}SiO{sub 4} and Li{sub 3}PO{sub 4}. The lithium content of the films was found to depend more strongly on the nature and composition of the targets than on many other sputtering parameters. For targets containing Li{sub 4}SiO{sub 4}, most of the lithium was found to segregate away from the sputtered area of the target. Codeposition using two sputter sources achieves a high lithium content in a controlled and reproducible film growth. 10 refs., 4 figs.

  16. Polymer and composite polymer slot waveguides

    NASA Astrophysics Data System (ADS)

    Hiltunen, Marianne; Fegadolli, William S.; Lira, Hugo L. R.; Vahimaa, Pasi; Hiltunen, Jussi; Aikio, Sanna; Almeida, Vilson R.; Karioja, Pentti

    2014-05-01

    A fully polymer slot Young interferometer operating at 633 nm wavelength was fabricated by using nanoimprint molding method. The phase response of the interference pattern was measured with several concentrations of glucose-water solutions, utilizing both TE and TM polarization states. The sensor was experimentally found to detect a bulk refractive index change of 6.4×10-6 RIU. Temperature dependency of silicon slot waveguide has been demonstrated to be reduced with composite slot waveguide structure. The slot filled with thermally stable polymer having negative thermo-optic coefficient showed nearly an athermal operation of silicon slot waveguide. Experimental results show that the slot waveguide geometry covered with Ormocomp has thermo-optical coefficient of 6 pm/K.

  17. Electro-optic Waveguide Beam Deflector.

    DTIC Science & Technology

    beam deflection by variation in the electro - optic effect produced within the waveguide region in response to known or determinable magnitude variations in the electrical potential of an applied signal source.

  18. Multistaged stokes injected Raman capillary waveguide amplifier

    DOEpatents

    Kurnit, Norman A.

    1980-01-01

    A multistaged Stokes injected Raman capillary waveguide amplifier for providing a high gain Stokes output signal. The amplifier uses a plurality of optically coupled capillary waveguide amplifiers and one or more regenerative amplifiers to increase Stokes gain to a level sufficient for power amplification. Power amplification is provided by a multifocused Raman gain cell or a large diameter capillary waveguide. An external source of CO.sub.2 laser radiation can be injected into each of the capillary waveguide amplifier stages to increase Raman gain. Devices for injecting external sources of CO.sub.2 radiation include: dichroic mirrors, prisms, gratings and Ge Brewster plates. Alternatively, the CO.sub.2 input radiation to the first stage can be coupled and amplified between successive stages.

  19. Photoreceptor waveguides and effective retinal image quality

    NASA Astrophysics Data System (ADS)

    Vohnsen, Brian

    2007-03-01

    Individual photoreceptor waveguiding suggests that the entire retina can be considered as a composite fiber-optic element relating a retinal image to a corresponding waveguided image. In such a scheme, a visual sensation is produced only when the latter interacts with the pigments of the outer photoreceptor segments. Here the possible consequences of photoreceptor waveguiding on vision are studied with important implications for the pupil-apodization method commonly used to incorporate directional effects of the retina. In the absence of aberrations, it is found that the two approaches give identical predictions for an effective retinal image only when the pupil apodization is chosen twice as narrow as suggested by the traditional Stiles-Crawford effect. In addition, phase variations in the retinal field due to ocular aberrations can delicately alter a waveguided image, and this may provide plausible justification for an improved visual sensation as compared with what should be expected on the grounds of a retinal image only.

  20. Wideband waveguide polarizer development for SETI

    NASA Technical Reports Server (NTRS)

    Lee, P.; Stanton, P.

    1991-01-01

    A wideband polarizer for the Deep Space Network (DSN) 34 meter beam waveguide antenna is needed for the Search for Extraterrestrial Intelligence (SETI) project. The results of a computer analysis of a wideband polarizer are presented.

  1. Radiation from Axisymmetric Waveguide Fed Horns

    NASA Technical Reports Server (NTRS)

    Chinn, G. C.; Hoppe, D. J.; Epp, L. W.

    1995-01-01

    Return losses and radiation patterns for axisymmetric waveguide fed horns are calculated with the finite element method (FEM) in conjunction with the method of moments (MoM) and the mode matching technique (MM).

  2. Flexible parylene-film optical waveguide arrays

    NASA Astrophysics Data System (ADS)

    Yamagiwa, S.; Ishida, M.; Kawano, T.

    2015-08-01

    Modulation of neuronal activities by light [e.g., laser or light-emitting diode] using optogenetics is a powerful tool for studies on neuronal functions in a brain. Herein, flexible thin-film optical waveguide arrays based on a highly biocompatible material of parylene are reported. Parylene-C and -N thin layers with the different refractive indices form the clad and the core of the waveguide, respectively, and neural recording microelectrodes are integrated to record optical stimuli and electrical recordings simultaneously using the same alignment. Both theoretical and experimental investigations confirm that light intensities of more than 90% can propagate in a bent waveguide with a curvature radius of >5 mm. The proposed flexible thin-film waveguide arrays with microelectrodes can be used for numerous spherical bio-tissues, including brain and spinal cord samples.

  3. Low-index discontinuity terahertz waveguides

    NASA Astrophysics Data System (ADS)

    Nagel, Michael; Marchewka, Astrid; Kurz, Heinrich

    2006-10-01

    A new type of dielectric THz waveguide based on recent approaches in the field of integrated optics is presented with theoretical and experimental results. Although the guiding mechanism of the low-index discontinuity (LID) THz waveguide is total internal reflection, the THz wave is predominantly confined in the virtually lossless low-index air gap within a high-index dielectric waveguide due to the continuity of electric flux density at the dielectric interface. Attenuation, dispersion and single-mode confinement properties of two LID structures are discussed and compared with other THz waveguide solutions. The new approach provides an outstanding combination of high mode confinement and low transmission losses currently not realizable with any other metal-based or photonic crystal approach. These exceptional properties might enable the breakthrough of novel integrated THz systems or endoscopy applications with sub-wavelength resolution.

  4. Optical Waveguide Output Couplers Fabricated in Polymers

    NASA Technical Reports Server (NTRS)

    Watson, Michael D.; Abushagur, Mustafa A. G.; Ashley, Paul R.; Johnson-Cole, Helen

    1998-01-01

    Waveguide output couplers fabricated in Norland Optical Adhesive (NOA) #81 and AMOCO Ultradel 9020D polyimide are investigated. The output couplers are implemented using periodic relief gratings on a planar waveguide. Design theory of the couplers is based on the perturbation approach. Coupling of light from waveguide propagation modes to output radiation modes is described by coupled mode theory and the transmission line approximation of the perturbed area (grating structure). Using these concepts, gratings can be accurately designed to output a minimum number of modes at desired output angles. Waveguide couplers were designed using these concepts. These couplers were fabricated and analyzed for structural accuracy, output beam accuracy, and output efficiency. The results for the two different materials are compared.

  5. Antiviral effect of lithium chloride.

    PubMed

    Cernescu, C; Popescu, L; Constantinescu, S; Cernescu, S

    1988-01-01

    Studies in human embryo fibroblasts infected with measles or herpes simplex virus showed a reduction in virus yield when cultures were pretreated with 1-10 mM lithium chloride doses. Maximum effect was obtained by a 1 h treatment with 10 mM lithium chloride, preceding viral infection by 19-24 hours. A specific antiviral effect against measles virus was manifest immediately after culture pretreatment. Intermittent treatment with 10 mM lithium chloride of cultures persistently infected with measles or herpes virus obtained from human myeloid K-562 cell line shows a reduction in the extracellular virus yield. In the K-562/herpes virus system, the culture treatment with lithium chloride and acyclovir (10 microM) has an additive inhibitory effect on virus production. The paper is focused on the mechanism of lithium chloride antiviral action and the expediency of lithium therapy in SSPE (subacute sclerosing panencephalitis).

  6. Experimental lithium system. Final report

    SciTech Connect

    Kolowith, R.; Berg, J.D.; Miller, W.C.

    1985-04-01

    A full-scale mockup of the Fusion Materials Irradiation Test (FMIT) Facility lithium system was built at the Hanford Engineering Development Laboratory (HEDL). This isothermal mockup, called the Experimental Lithium System (ELS), was prototypic of FMIT, excluding the accelerator and dump heat exchanger. This 3.8 m/sup 3/ lithium test loop achieved over 16,000 hours of safe and reliable operation. An extensive test program demonstrated satisfactory performance of the system components, including the HEDL-supplied electromagnetic lithium pump, the lithium jet target, the purification and characterization hardware, as well as the auxiliary argon and vacuum systems. Experience with the test loop provided important information on system operation, performance, and reliability. This report presents a complete overview of the entire Experimental Lithium System test program and also includes a summary of such areas as instrumentation, coolant chemistry, vapor/aerosol transport, and corrosion.

  7. Optical waveguide device with an adiabatically-varying width

    DOEpatents

    Watts; Michael R. , Nielson; Gregory N.

    2011-05-10

    Optical waveguide devices are disclosed which utilize an optical waveguide having a waveguide bend therein with a width that varies adiabatically between a minimum value and a maximum value of the width. One or more connecting members can be attached to the waveguide bend near the maximum value of the width thereof to support the waveguide bend or to supply electrical power to an impurity-doped region located within the waveguide bend near the maximum value of the width. The impurity-doped region can form an electrical heater or a semiconductor junction which can be activated with a voltage to provide a variable optical path length in the optical waveguide. The optical waveguide devices can be used to form a tunable interferometer (e.g. a Mach-Zehnder interferometer) which can be used for optical modulation or switching. The optical waveguide devices can also be used to form an optical delay line.

  8. An Investigation of Dielectric Loaded Ridged Waveguide.

    DTIC Science & Technology

    1986-03-31

    propagation in any waveguide may be characterized by its field distribution. For homogeneous waveguides, modes are usually classified as TE (transverse...modes other than TE,,,.0 are characterized as LSE or LSM. Introduction of the ridge will cause distortion of the fields from true LSE or LSM nature...specify each of the LSE and LSM modes with any given mode characterized as the LSEm, mode or the LSM ,, mode. The first index m refers to the

  9. Broadband waveguide QED system on a chip

    SciTech Connect

    Quan Qimin; Bulu, Irfan; Loncar, Marko

    2009-07-15

    We demonstrate that a slot waveguide provides a broadband loss-free platform suitable for applications in quantum optics. We find that strong coupling between light quanta and a single quantum emitter placed in the waveguide slot can be achieved with efficiency higher than 96% and Purcell factor (spontaneous emission factor) larger than 200. The proposed system is a promising platform for quantum information processing and can be used to realize an efficient single photon source and optically addressable photon register.

  10. Membranes in lithium ion batteries.

    PubMed

    Yang, Min; Hou, Junbo

    2012-07-04

    Lithium ion batteries have proven themselves the main choice of power sources for portable electronics. Besides consumer electronics, lithium ion batteries are also growing in popularity for military, electric vehicle, and aerospace applications. The present review attempts to summarize the knowledge about some selected membranes in lithium ion batteries. Based on the type of electrolyte used, literature concerning ceramic-glass and polymer solid ion conductors, microporous filter type separators and polymer gel based membranes is reviewed.

  11. Sealed Lithium Inorganic Electrolyte Cell

    DTIC Science & Technology

    1976-03-01

    revere side it necoeery and idM,1117 "~ bfoh numiber) Inorganic Electrolyte Battery Carbon Cathode Evaluation Thionyl Chloride Gas Generation Lithium ...hardware corrosion in cold rolled steel cans, due to cathodic protection of the cans by the lithium . Recent data 4 showed that thionyl chloride is reduced...very slowly on the surface of nickel and stainless steel, when these materials were in contact with a lithium anode in the thionyl chloride

  12. Light transmission loss in liquid crystal waveguides

    NASA Astrophysics Data System (ADS)

    Nowinowski-Kruszelnicki, Edward; Walczak, Andrzej; Kiezun, Aleksander; Jaroszewicz, Leszek R.

    1998-02-01

    The investigation results of the propagation loss due to light scattering in electrically induced channel in planar waveguides are presented. The channel structure was obtained by means of electric driven stripe electrode made by photolithographic process. Planar waveguiding cell has been fabricated using ITO/SiO2/polyimide-coated glass plates and LC film 20 micrometers thick. A nematic liquid crystal layer with 90 degrees-twisted nematic orientation was studied. The He-Ne light beam was endfire coupled into an input edge of a waveguide using an objective lens. The propagation loss have been evaluated from the spatial variation intensity of light scattered out perpendicularly to the waveguide surface along the light propagation direction measured with CCD camera. Loss measurements have been made in room temperature. Waveguiding channel effect has been observed above 2.5 Vrms of applied voltage with the loss of about 17 +/- 1 dB. Increased driving voltage up to 100 Vrms reduces the loss to minimum value of 12 +/- 1 dB/cm. As a result of the experiments one may conclude that transmission loss in thick nematic waveguide have bulk character caused by imperfection of molecular alignment.

  13. Towards new applications using capillary waveguides

    PubMed Central

    Stasio, Nicolino; Shibukawa, Atsushi; Papadopoulos, Ioannis N.; Farahi, Salma; Simandoux, Olivier; Huignard, Jean-Pierre; Bossy, Emmanuel; Moser, Christophe; Psaltis, Demetri

    2015-01-01

    In this paper we demonstrate the enhancement of the sensing capabilities of glass capillaries. We exploit their properties as optical and acoustic waveguides to transform them potentially into high resolution minimally invasive endoscopic devices. We show two possible applications of silica capillary waveguides demonstrating fluorescence and optical-resolution photoacoustic imaging using a single 330 μm-thick silica capillary. A nanosecond pulsed laser is focused and scanned in front of a capillary by digital phase conjugation through the silica annular ring of the capillary, used as an optical waveguide. We demonstrate optical-resolution photoacoustic images of a 30 μm-thick nylon thread using the water-filled core of the same capillary as an acoustic waveguide, resulting in a fully passive endoscopic device. Moreover, fluorescence images of 1.5 μm beads are obtained collecting the fluorescence signal through the optical waveguide. This kind of silica-capillary waveguide together with wavefront shaping techniques such as digital phase conjugation, paves the way to minimally invasive multi-modal endoscopy. PMID:26713182

  14. Advanced lithium ion battery charger

    SciTech Connect

    Teofilo, V.L.; Merritt, L.V.; Hollandsworth, R.P.

    1997-12-01

    A lithium ion battery charger has been developed for four and eight cell batteries or multiples thereof. This charger has the advantage over those using commercial lithium ion charging chips in that the individual cells are allowed to be taper charged at their upper charging voltage rather than be cutoff when all cells of the string have reached the upper charging voltage limit. Since 30--60% of the capacity of lithium ion cells maybe restored during the taper charge, this charger has a distinct benefit of fully charging lithium ion batteries by restoring all of the available capacity to all of its cells.

  15. Lithium-Inorganic Electrolyte Batteries.

    DTIC Science & Technology

    PRIMARY BATTERIES , TEMPERATURE, LITHIUM , CATHODES, ELECTRODES, PROTECTIVE COATINGS, PLATINUM, NICKEL, SULFUR, STORAGE, GOLD, RELIABILITY(ELECTRONICS...CHEMICAL ANALYSIS, CARBON BLACK, GAS CHROMATOGRAPHY, THIONYL CHLORIDE , REDUCTION(CHEMISTRY).

  16. Light wheel confined in a purely dielectric composite waveguide.

    PubMed

    Ye, Yu Qian; Jin, Yi; He, Sailing

    2009-03-16

    A properly designed composite waveguide consisting of a one-dimensional photonic crystal waveguide and a conventional dielectric waveguide is proposed for the realization of a localized "light wheel". Light confinedly rotating between the two waveguides is numerically demonstrated and explained physically in detail. A delocalized "light wheel" is found at the band gap edge caused by contra-directional coupling between the two waveguides. Because of this delocalized "light wheel" , the composite waveguide can be used to trap light as a cavity, and a quality factor of 9 x 10(3) is achieved as an example. The present structure is completely dielectric and thus easy to realize with a low loss.

  17. Ion-exchanged glass waveguide technology: a review

    NASA Astrophysics Data System (ADS)

    Tervonen, Ari; West, Brian R.; Honkanen, Seppo

    2011-07-01

    We review the history and current status of ion exchanged glass waveguide technology. The background of ion exchange in glass and key developments in the first years of research are briefly described. An overview of fabrication, characterization and modeling of waveguides is given and the most important waveguide devices and their applications are discussed. Ion exchanged waveguide technology has served as an available platform for studies of general waveguide properties, integrated optics structures and devices, as well as applications. It is also a commercial fabrication technology for both passive and active wave-guide components.

  18. Optimized lithium oxyhalide cells

    NASA Astrophysics Data System (ADS)

    Kilroy, W. P.; Schlaikjer, C.; Polsonetti, P.; Jones, M.

    1993-04-01

    Lithium thionyl chloride cells were optimized with respect to electrolyte and carbon cathode composition. Wound 'C-size' cells with various mixtures of Chevron acetylene black with Ketjenblack EC-300J and containing various concentrations of LiAlCl4 and derivatives, LiGaCl4, and mixtures of SOCl2 and SO2Cl2 were evaluated as a function of discharge rate, temperature, and storage condition.

  19. Ultralow-loss waveguide crossings for the integration of microfluidics and optical waveguide sensors

    NASA Astrophysics Data System (ADS)

    Wang, Zheng; Yan, Hai; Wang, Zongxing; Zou, Yi; Yang, Chun-Ju; Chakravarty, Swapnajit; Subbaraman, Harish; Tang, Naimei; Xu, Xiaochuan; Fan, D. L.; Wang, Alan X.; Chen, Ray T.

    2015-03-01

    Integrating photonic waveguide sensors with microfluidics is promising in achieving high-sensitivity and cost-effective biological and chemical sensing applications. One challenge in the integration is that an air gap would exist between the microfluidic channel and the photonic waveguide when the micro-channel and the waveguide intersect. The air gap creates a path for the fluid to leak out of the micro-channel. Potential solutions, such as oxide deposition followed by surface planarization, would introduce additional fabrication steps and thus are ineffective in cost. Here we propose a reliable and efficient approach for achieving closed microfluidic channels on a waveguide sensing chip. The core of the employed technique is to add waveguide crossings, i.e., perpendicularly intersecting waveguides, to block the etched trenches and prevent the fluid from leaking through the air gap. The waveguide crossings offer a smooth interface for microfluidic channel bonding while bring negligible additional propagation loss (0.024 dB/crossing based on simulation). They are also efficient in fabrication, which are patterned and fabricated in the same step with waveguides. We experimentally integrated microfluidic channels with photonic crystal (PC) microcavity sensor chips on silicon-on-insulator substrate and demonstrated leak-free sensing measurement with waveguide crossings. The microfluidic channel was made from polydimethylsiloxane (PDMS) and pressure bonded to the silicon chip. The tested flow rates can be varied from 0.2 μL/min to 200 μL/min. Strong resonances from the PC cavity were observed from the transmission spectra. The spectra also show that the waveguide crossings did not induce any significant additional loss or alter the resonances.

  20. Solid lithium-ion electrolyte

    DOEpatents

    Zhang, J.G.; Benson, D.K.; Tracy, C.E.

    1998-02-10

    The present invention relates to the composition of a solid lithium-ion electrolyte based on the Li{sub 2}O--CeO{sub 2}--SiO{sub 2} system having good transparent characteristics and high ion conductivity suitable for uses in lithium batteries, electrochromic devices and other electrochemical applications. 12 figs.