DOCSLIB.ORG

Optical Properties of KTP Crystals and Their Potential for Terahertz Generation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Optical Properties of KTP Crystals and Their Potential for Terahertz Generation crystals Article Optical Properties of KTP Crystals and Their Potential for Terahertz Generation Alexander Mamrashev 1,* ID , Nazar Nikolaev 1 ID , Valery Antsygin 1, Yury Andreev 2,3, Grigory Lanskii 2,3 and Arkady Meshalkin 4 1 Institute of Automation & Electrometry, SB RAS, 1, Ac. Koptyug Ave., Novosibirsk 630090, Russia; [email protected] (N.N.); [email protected] (V.A.) 2 Institute of Monitoring of Climatic and Ecological Systems, SB RAS, 10/3, Akademicheskii Ave., Tomsk 634055, Russia; [email protected] (Y.A.); [email protected] (G.L.) 3 Siberian Physical Technical Institute of Tomsk State University, 1 Novosobornaya Sq., Tomsk 634050, Russia 4 Institute of Thermophysics, SB RAS, 1, Ac. Lavrent’ev Ave., Novosibirsk 630090, Russia; [email protected] * Correspondence: [email protected]; Tel.: +7-383-330-8378 Received: 30 June 2018; Accepted: 28 July 2018; Published: 31 July 2018 Abstract: High nonlinearity, wide transparency range and optical quality allowed potassium titanyl phosphate (KTiOPO4, KTP) crystals to be used in a wide range of nonlinear applications. The success of KTP usage in the visible and infrared (IR) ranges drives interest in applying it at longer wavelengths, that is, in the terahertz (THz) range. We use THz optical properties of KTP crystals measured by terahertz time-domain spectrometer (THz-TDS) and refractive index approximated in the form of Sellmeier equations to investigate KTP application possibilities for IR-to-THz and THz-to-THz wave conversion. As a result, phase matching for s − f ! f and s − f ! s types of difference frequency generation (DFG) of Ti:Sapphire laser (at the wavelengths of 0.65, 0.8 and 1.1 µm) is found possible, as well as second harmonic generation (SHG) of THz waves by f + s ! f type of interaction in the XZ principle plane of the crystal. Terahertz wave generation by phase-matched parametric processes in KTP demonstrates evident advantages in comparison with that of widely used MgO-doped LiNbO3 crystals. Keywords: KTP; nonlinear crystal; frequency conversion; SHG; DFG; THz radiation; THz wave 1. Introduction Potassium titanyl phosphate (KTiOPO4, KTP) is one of the most widely used nonlinear optical crystals [1]. KTP belongs to the mm2 point group symmetry and its dielectric and crystallographic axes are assigned as X, Y, Z ! a, b, c. Its structure consists of chains of connected rigid PO4 tetrahedra and TiO6 octahedra with alternating long and short Ti–O bonds that are responsible for its nonlinear properties [2]. KTP advantages are high nonlinear coefficients: d15 = 1.9 pm/V, d24 = 4.2 pm/V, d31 = 2.2 pm/V, d32 = 2.7 pm/V and d33 = 17.4 pm/V, wide ranges of angles and temperatures for the phase matching, low absorption in the range of 0.35 µm to 4.5 µm, excellent mechanical stability and optical quality. One of the few KTP disadvantages is its susceptibility to photochromic damage, that is, grey-tracking, that causes slow deterioration of light conversion efficiency. The abovementioned properties of KTP determine its wide range of nonlinear applications such as sum [3] and difference [4,5] frequency generation (SFG and DFG), second harmonic generation (SHG) [6], optical parametric oscillation/generation (OPO/OPG) and amplification (OPA) [7–9]. Parametric generation based on stimulated polariton scattering in KTP shows superior performance in terms of gain and laser damage resistance in comparison to lithium niobate and lithium tantalate [10,11]. Other KTP applications include modulators for the near- and the mid-IR ranges [12–14]. Crystals 2018, 8, 310; doi:10.3390/cryst8080310 www.mdpi.com/journal/crystals Crystals 2018, 8, 310 2 of 8 Crystals 2018, 8, x FOR PEER REVIEW 2 of 8 The successsuccess ofof KTP KTP nonlinear nonlinear applications applications in the in visiblethe visible and IR and ranges IR drivesranges interestdrives ininterest studying in itsstudying terahertz its dielectricterahertz anddielectric optical and (THz) optical properties (THz) topr substituteoperties to the substitute widely usedthe widely pure and used MgO-doped pure and lithiumMgO-doped niobate lithium crystals niobate (LiNbO crystals3, LN) (LiNbO in this3, LN) range in [this15]. range Previously, [15]. Previously, infrared reflectivity infrared reflectivity spectrum ofspectrum KTP was of studiedKTP was up studied to the wavenumberup to the wavenumber of 4000 cm of− 40001 (120 cm THz)−1 (120 at THz) the temperatures at the temperatures of 7 K, 80 of K7 andK, 80 293 K and K [16 293]. Later,K [16]. the Later, results the wereresults supplemented were supplemented by Raman by Raman spectroscopy spectroscopy measurements measurements at the wavenumbersat the wavenumbers below below 4000 cm 4000−1 [cm17].−1 Recently,[17]. Recently, THz refractiveTHz refractive index index and absorption and absorption coefficient coefficient were directlywere directly measured measured using using growingly growingly accessible accessible THz THz time-domain time-domain spectrometers spectrometers (THz-TDS) (THz-TDS) [18 –[18–21]. The21]. The most most comprehensive comprehensive study study of its of THz its THz optical optical properties properties for thefor the waves waves polarized polarized parallel parallel to allto threeall three optical optical axes axes of the of KTPthe KTP crystals crystals was was carried carrie outd inout [20 in]. [20]. The refractiveThe refractive index index components components at room at temperatureroom temperature were approximatedwere approximated in the in form the of form Sellmeier of Sellmeier equations equations [21]. [21]. In this paper, wewe reportreport terahertzterahertz optical propertiesproperties of KTP crystals at the room temperature of 293 K (RT)(RT) andand atat thethe liquid liquid nitrogen nitrogen temperature temperature of of 81 81 K andK and calculate calculate phase-matching phase-matching conditions conditions for nonlinearfor nonlinear frequency frequency conversion conversion into into and and within within the the THz THz range. range. 2. Materials and Methods KTP single-crystalsingle-crystal ingotsingots were were grown grown using using the the Czochralski Czochralski method method from from a Pt a crucible Pt crucible of 100 of mm100 inmm diameter. in diameter. The crucible The crucible closed closed with Pt with cover Pt with cover about with 1 about kg of charge1 kg of was charge disposed was indisposed the resistivity in the oven.resistivity After oven. heating, After the heating, melt was the homogenized melt was homogenized and cooled downand cooled to liquidus downtemperature. to liquidus temperature. The crystals wereThe crystals grown were using grown single-domain using single-domain seed in the directionseed in the of directionX-axis. Duringof X-axis. the During growth the period growth of ◦ ◦ 45–55period days, of 45–55 the meltdays, was the cooled melt was down cooled by 70–120 down C.by The70–120 cooling °С. rateThe ofcooling the crystal rate of was the 0.1–4 crystalC/day was while0.1–4 ° itsС/day rotation while speed its rotation varied from speed 30 tovaried 40 rpm. from In 30 parallel, to 40 therpm. pulling In parallel, speed changedthe pulling from speed 0 to 1.2changed mm/day. from By 0 selectingto 1.2 mm/day. optimal By growth selecting conditions optima high-qualityl growth conditions single-crystal high-quality ingots having single-crystal a weight 3 ofingots 260 ghaving and dimensions a weight of of 260X ×g andY × dimensionsZ = 40 × 60 of× X70 × mm Y × Zwere = 40 grown.× 60 × 70 mm3 were grown. 3 At first,first, a large plateplate withwith dimensionsdimensions ofof XX × YY ×× ZZ == 11 11 × ×2828 × ×58 58mm mm3 waswas manufactured manufactured to toevaluate evaluate the the quality quality of ofthe the grown grown crystal crystal and and me measureasure its its transmission transmission spectrum spectrum in in the main transparency window. window. Then Then three three pairs pairs samples samples with with different different thickness thickness with dimensions with dimensions of 10 × 10 of 3 10× (0.28,× 10 0.35× (0.28 and, 0.351.08) and mm 1.08)3 were mm cut orthogonalwere cut orthogonal to the optical to the axes optical X (KTP axesx) andX (KTP Z (KTPx) andz) (FigureZ (KTP 1).z) (FigureSides of1 ).the Sides KTP ofx thesample KTP werex sample parallel were to parallel the Y toand the ZY axesand andZ axes sides and of sides the ofKTP thez KTPsamplez sample were wereparallel parallel to the to X the andX andY axes.Y axes. So, every So, every pair pair of samples of samples allowed allowed us usto tomeasure measure all all three three (x (x, ,yy andand zz)) components of the absorption coefficientcoefficient and refractiverefractive index for waves polarized parallel to the X, Y and Z axes, respectively and select the best-thickness crystalscrystals forfor thethe study.study. Figure 1. A pair of prepared KTP crystal samples cut orthogonal to the X and Z axes. Figure 1. A pair of prepared KTP crystal samples cut orthogonal to the X and Z axes. Transmission spectra in the transparency window were measured by UV-2101/3101 Transmission spectra in the transparency window were measured by UV-2101/3101 spectrophotometer (Shimadzu, Kyoto, Japan). Terahertz optical properties were studied using a spectrophotometer (Shimadzu, Kyoto, Japan). Terahertz optical properties were studied using THz-TDS (IA&E SB RAS, Novosibirsk, Russia) with a cryostat described elsewhere [20] at the temperatures of 293 K and 81 K. Crystals 2018, 8, 310 3 of 8 a THz-TDS (IA&E SB RAS, Novosibirsk, Russia) with a cryostat described elsewhere [20] at the temperaturesCrystals 2018, 8, x of FOR 293 PEER K and REVIEW 81 K. 3 of 8 3.3. Results TheThe resistivityresistivity ofof aa growngrown KTPKTP crystalcrystal isis oneone ofof indicatorsindicators ofof itsits quality.quality. HigherHigher valuesvalues ofof resistivityresistivity makemake the the crystals crystals applicable applicable for manufacturingfor manufacturing electro-optic electro-optic devices: devices: amplitude amplitude and phase and modulatorsphase modulators [12].
Load more

Recommended publications
  • Theories of Low Energy Nuclear Transmutations
    Theories of Low Energy Nuclear Transmutations Y. N. Srivastava Department of Physics & INFN, University of Perugia, Perugia, IT A. Widom and J. Swain Physics Department, Northeastern University, Boston MA, USA Employing concrete examples from nuclear physics it is shown that low energy nuclear reactions can and have been induced by all of the four fundamental interactions (i) (stellar) gravitational, (ii) strong, (iii) electromagnetic and (iv) weak. Differences are highlighted through the great diversity in the rates and similarity through the nature of the nuclear reactions initiated by each. PACS numbers: 26.65.+t, 96.60.Jw, 25.85.Ec, 29.25.Dz,24.75.+i, 25.85.-w, 28.41.Ak,24.75.+i I. INTRODUCTION We show below through physical examples that low energy nuclear reactions have been induced by all of the four fundamental interactions: gravitational, strong, electromagnetic and weak. Gravity: Gravitational interactions are well known to cause nuclear reactions and fusion in a star. Were it not for nuclear activity, a star would be dynamically unstable and undergo gravitational collapse[1, 2]. In fact, standard theory predicts the collapse of a star when the nuclear fuel is exhausted as the star can no longer counteract the inward compression due to gravitation. Nuclear: A laboratory example of low energy strong interaction fusion is provided by a fast discharge in fine deuterated polymer fibers. In such fibers, deuterons are accelerated to speeds high enough to overcome the barrier due to mutual Coulomb repulsion, giving rise to the production of 2:5 MeV neutrons through low energy reactions such as d + d ! n + 3He: (1) In the same set of experiments[3], also non deuterated fibers exhibit an \anomalous" production of neutrons, at a rate over 6 orders of magnitude larger than that expected through natural contamination of deuterons in a normal material.
    [Show full text]
  • In-Depth Analysis by Co-Imaging of Periodically-Poled X-Cut Lithium Niobate Thin Films
    crystals Article “Seeing Is Believing”—In-Depth Analysis by Co-Imaging of Periodically-Poled X-Cut Lithium Niobate Thin Films Sven Reitzig 1,* , Michael Rüsing 1, Jie Zhao 2,†, Benjamin Kirbus 1, Shayan Mookherjea 2 and Lukas M. Eng 1,3 1 Institut für Angewandte Physik, Technische Universität Dresden, 01062 Dresden, Germany; [email protected] (M.R.); [email protected] (B.K.); [email protected] (L.M.E.) 2 Department of Electrical and Computer Engineering, University of California, San Diego, CA 92161, USA; [email protected] (J.Z.); [email protected] (S.M.) 3 ct.qmat: Dresden-Würzburg Cluster of Excellence—EXC 2147, TU Dresden, 01062 Dresden, Germany * Correspondence: [email protected]; Tel.: +49-351-463-43354 † Since February 2021 affiliated with Nokia Bell Labs, Murray Hill, NJ 07974, USA. Abstract: Nonlinear and quantum optical devices based on periodically-poled thin film lithium niobate (PP-TFLN) have gained considerable interest lately, due to their significantly improved performance as compared to their bulk counterparts. Nevertheless, performance parameters such as conversion efficiency, minimum pump power, and spectral bandwidth strongly depend on the quality of the domain structure in these PP-TFLN samples, e.g., their homogeneity and duty cycle, as well as on the overlap and penetration depth of domains with the waveguide mode. Hence, in order to propose improved fabrication protocols, a profound quality control of domain structures is needed that allows quantifying and thoroughly analyzing these parameters. In this paper, we Citation: Reitzig, S.; Rüsing, M.; propose to combine a set of nanometer-to-micrometer-scale imaging techniques, i.e., piezoresponse Zhao, J.; Kirbus, B.; Mookherjea, S.; force microscopy (PFM), second-harmonic generation (SHG), and Raman spectroscopy (RS), to access Eng, L.M.
    [Show full text]
  • High Temperature Ultrasonic Transducers: a Review
    sensors Review High Temperature Ultrasonic Transducers: A Review Rymantas Kazys * and Vaida Vaskeliene Ultrasound Research Institute, Kaunas University of Technology, Barsausko st. 59, LT-51368 Kaunas, Lithuania; [email protected] * Correspondence: [email protected] Abstract: There are many fields such as online monitoring of manufacturing processes, non-destructive testing in nuclear plants, or corrosion rate monitoring techniques of steel pipes in which measure- ments must be performed at elevated temperatures. For that high temperature ultrasonic transducers are necessary. In the presented paper, a literature review on the main types of such transducers, piezoelectric materials, backings, and the bonding techniques of transducers elements suitable for high temperatures, is presented. In this review, the main focus is on ultrasonic transducers with piezoelectric elements suitable for operation at temperatures higher than of the most commercially available transducers, i.e., 150 ◦C. The main types of the ultrasonic transducers that are discussed are the transducers with thin protectors, which may serve as matching layers, transducers with high temperature delay lines, wedges, and waveguide type transducers. The piezoelectric materi- als suitable for high temperature applications such as aluminum nitride, lithium niobate, gallium orthophosphate, bismuth titanate, oxyborate crystals, lead metaniobate, and other piezoceramics are analyzed. Bonding techniques used for joining of the transducer elements such as joining with glue, soldering,
    [Show full text]
  • Arxiv:2002.06594V2 [Physics.Optics] 26 Oct 2020 Tives to the Metallic Nanostructures
    Resonantly tunable second harmonic generation from lithium niobate metasurfaces Junjun Ma,1 Fei Xie,1 Weijin Chen,2 Jiaxin Chen,1 Wei Wu,1 Wei Liu,3 Yuntian Chen,2 Wei Cai,1 Mengxin Ren,1, 4, a) and Jingjun Xu1, b) 1)The Key Laboratory of Weak-Light Nonlinear Photonics, Ministry of Education, School of Physics and TEDA Applied Physics Institute, Nankai University, Tianjin 300071, P.R. China 2)School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan, Hubei 430074, P.R.China 3)College for Advanced Interdisciplinary Studies, National University of Defense Technology, Changsha, Hunan 410073, P.R.China 4)Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, P.R. China (Dated: 27 October 2020) Second harmonic generation (SHG) is a coherent nonlinear phenomenon that plays an important role in laser color conversion. Lithium niobate (LN), which features both a large band gap and outstanding second-order nonlinearities, acts as an important optical material for nonlinear frequency conversion covering a wide spectral range from ultraviolet to mid-infrared. Here we experimentally demonstrate LN metasurfaces with controllable SHG properties. Distinct enhancements for the SHG efficiency are observed at Mie-resonances. And by changing the geometric parameters thus the resonances of the metasurfaces, we manage to selectively boost the SHG efficiency at different wavelengths. Our results would pave a way for developing with high flexibility the novel compact nonlinear light sources for applications, such as biosensing and optical communications. Keywords: Lithium niobate, Metasurface, Second harmonic generation, Resonance Second harmonic generation (SHG) plays a key role diffraction limit.
    [Show full text]
  • Integrated Photonics on Thin-Film Lithium Niobate
    Integrated photonics on thin-film lithium niobate DI ZHU,1,* LINBO SHAO,1 MENGJIE YU,1 REBECCA CHENG,1 BORIS DESIATOV,1 C. J. XIN,1 YAOWEN HU,1 JEFFREY HOLZGRAFE,1 SOUMYA GHOSH,1 AMIRHASSAN SHAMS-ANSARI,1 ERIC PUMA,1 NEIL SINCLAIR,1,2 CHRISTIAN REIMER,3 MIAN ZHANG,3 AND MARKO LONČAR1,* 1John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA 2Division of Physics, Mathematics and Astronomy, and Alliance for Quantum Technologies (AQT), California Institute of Technology, 1200 E. California Boulevard, Pasadena, CA 91125, USA 3HyperLight Corporation, 501 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA [email protected], [email protected] Lithium niobate (LN), an outstanding and versatile material, has influenced our daily life for decades: from enabling high-speed optical communications that form the backbone of the Internet to realizing radio-frequency filtering used in our cell phones. This half-century-old material is currently embracing a revolution in thin-film LN integrated photonics. The success of manufacturing wafer-scale, high-quality, thin films of LN on insulator (LNOI), accompanied with breakthroughs in nanofabrication techniques, have made high-performance integrated nanophotonic components possible. With rapid development in the past few years, some of these thin-film LN devices, such as optical modulators and nonlinear wavelength converters, have already outperformed their legacy counterparts realized in bulk LN crystals. Furthermore, the nanophotonic integration enabled ultra-low-loss resonators in LN, which unlocked many novel applications such as optical frequency combs and quantum transducers. In this Review, we cover—from basic principles to the state of the art—the diverse aspects of integrated thin- film LN photonics, including the materials, basic passive components, and various active devices based on electro-optics, all-optical nonlinearities, and acousto-optics.
    [Show full text]
  • A Study of Lithium Precursors on Nanoparticle Quality
    Electronic Supplementary Material (ESI) for Nanoscale. This journal is © The Royal Society of Chemistry 2021 Electronic Supplementary Information Elucidating the role of precursors in synthesizing single crystalline lithium niobate nanomaterials: A study of lithium precursors on nanoparticle quality Rana Faryad Ali, Byron D. Gates* Department of Chemistry and 4D LABS, Simon Fraser University, 8888 University Drive Burnaby, BC, V5A 1S6, Canada * E-mail: [email protected] This work was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC; Grant No. RGPIN-2020-06522), and through the Collaborative Health Research Projects (CHRP) Partnership Program supported in part by the Canadian Institutes of Health Research (Grant No. 134742) and the Natural Science Engineering Research Council of Canada (Grant No. CHRP 462260), the Canada Research Chairs Program (B.D. Gates, Grant No. 950-215846), CMC Microsystems (MNT Grant No. 6345), and a Graduate Fellowship (Rana Faryad Ali) from Simon Fraser University. This work made use of 4D LABS (www.4dlabs.com) and the Center for Soft Materials shared facilities supported by the Canada Foundation for Innovation (CFI), British Columbia Knowledge Development Fund (BCKDF), Western Economic Diversification Canada, and Simon Fraser University. S1 Experimental Materials and supplies All chemicals were of analytical grade and were used as received without further purification. Niobium ethoxide [Nb(OC2H5)5, >90%] was obtained from Gelest Inc., and benzyl alcohol (C7H7OH, 99%) and triethylamine [N(C2H5)3, 99.0%] were purchased from Acros Organics and Anachemia, respectively. Lithium chloride (LiCl, ~99.0%) was obtained from BDH Chemicals, and lithium bromide (LiBr, ≥99.0%), lithium fluoride (LiF, ~99.9%), and lithium iodide (LiI, 99.0%) were purchased from Sigma Aldrich.
    [Show full text]
  • Unveiling the Defect Structure of Lithium Niobate with Nuclear Methods
    crystals Review Unveiling the Defect Structure of Lithium Niobate with Nuclear Methods Andreas Kling * and José G. Marques Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, km 139.7, P-2695-066 Bobadela, Portugal; [email protected] * Correspondence: [email protected]; Tel.: +351-219-946-154 Abstract: X-ray and neutron diffraction studies succeeded in the 1960s to determine the principal structural properties of congruent lithium niobate. However, the nature of the intrinsic defects related to the non-stoichiometry of this material remained an object of controversial discussion. In addition, the incorporation mechanism for dopants in the crystal lattice, showing a solubility range from about 0.1 mol% for rare earths to 9 mol% for some elements (e.g., Ti and Mg), stayed unresolved. Various different models for the formation of these defect structures were developed and required experimental verification. In this paper, we review the outstanding role of nuclear physics based methods in the process of unveiling the kind of intrinsic defects formed in congruent lithium niobate and the rules governing the incorporation of dopants. Complementary results in the isostructural compound lithium tantalate are reviewed for the case of the ferroelectric-paraelectric phase transition. We focus especially on the use of ion beam analysis under channeling conditions for the direct determination of dopant lattice sites and intrinsic defects and on Perturbed Angular Correlation measurements probing the local environment of dopants in the host lattice yielding independent and complementary information. Citation: Kling, A.; Marques, J.G. Unveiling the Defect Structure of Keywords: lithium niobate; intrinsic defects; extrinsic defects; lattice location; radiation damage; ion Lithium Niobate with Nuclear beam analysis; hyperfine interactions Methods.
    [Show full text]
  • And Nanoscale Domain Engineering in Lithium Niobate and Lithium Tantalate Vladimir Ya
    Micro- and nanoscale domain engineering in lithium niobate and lithium tantalate Vladimir Ya. Shur*a, Evgenii Rumyantsev a Ekaterina Nikolaeva a Eugene Shishkin a b Robert G. Batchko b Gregory D. Miller b Martin M. Fejerb Robert L.Byer alflSt of Phys. & App!. Math., Ural State Univ., Ekaterinburg 620083, Russia bEL Ginzton Laboratory, Stanford University, Stanford, CA 94305-4085 ABSTRACT We present detail investigation of the domain evolution in lithium niobate and lithium tantalate during backswitched electric field poling which allowed to produce micro- and nanoscale domain patterns by application of voltage to lithographically defined strip electrodes. In situ optical observation of the domain kinetics during poling and high-resolution visualization by SEM and SFM of the static domain patterns on polar surfaces and cross-sections have been used. We separated and studied the main stages of domain evolution. The important role of backswitching as a powerfiul tool for high-fidelity domain patterning in thick wafers and for production of quasi-periodic nanoscale domain patterns has been demonstrated. We have proposed several variants of domain manipulation during backswitched poling: the frequency multiplication of the domain patterns, domain "erasing" and "splitting", formation of oriented arrays of nanoscale domains. We have demonstrated the production of lamellar domain patterns with period down to 2.6 microns in 0.5-mm-thick wafers and strictly oriented quasi- periodic domain arrays consisting of the individual nanodomains with diameter down to 30 nm and density up to 100 per square micron. Keywords: domain patterning, backswitchmg, nanotechnology, electric field poling, domain manipulation. 1. INTRODUCTION In recent years rapid development of a new branch of technology named the microdomain engineering raised the questions of fabrication of ferroelectric domain patterns with periods about several microns.
    [Show full text]
  • Powder Synthesis and Properties of Litao3 Ceramics ⇑ Tao Yang, Yan-Gai Liu , Lei Zhang, Mei-Ling Hu, Qian Yang, Zhao-Hui Huang, Ming-Hao Fang
    Advanced Powder Technology 25 (2014) 933–936 Contents lists available at ScienceDirect Advanced Powder Technology journal homepage: www.elsevier.com/locate/apt Original Research Paper Powder synthesis and properties of LiTaO3 ceramics ⇑ Tao Yang, Yan-gai Liu , Lei Zhang, Mei-ling Hu, Qian Yang, Zhao-hui Huang, Ming-hao Fang School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083, PR China article info abstract Article history: The LiTaO3 powders with sub micrometer grade grain size have been synthesized successfully using a Received 26 April 2013 molten salt method. Lithium tantalate began to form at 400 °C reaction temperature and transformed Received in revised form 8 January 2014 to pure phase without residual reactants when it was processed at 500 °C for 4 h in static air. The Accepted 17 January 2014 undoped LiTaO ceramics with a Curie temperature about 663 °C were obtained by pressureless sintering Available online 28 January 2014 3 at 1300 °C for 3 h. The relative dielectric constant (er) increases from 50 to 375 at temperature ranging from 30 to 663 °C and then decreases quickly as the temperature increases above 663 °C. The ceramics Keywords: shows a relative dielectric constant of 49.4, a dielectric loss factor (tand) of 0.007, a coercive field (Ec) Lithium tantalite ceramics of 28.66 kV/cm and a remnant polarization (Pr) of 32.48 C/cm2 at room temperature. Molten salt method l Sintering Ó 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Ferroelectric properties Technology Japan.
    [Show full text]
  • Tourmalines and Relaxor Ferroelectrics of The
    Correlations between Crystal Structure and Elastic Properties of Piezoelectric Crystals: Tourmalines and Relaxor Ferroelectrics of the type CaxBa1-xNb2O6 and Ce:CaxBa1-xNb2O6 DISSERTATION zur Erlangung des akademischen Grades eines “Doktor der Naturwissenschaften” an der Fakultät für Geowissenschaften der Ruhr-Universität Bochum Germany von Chandra Shekhar Pandey aus Bareilly (India) Bochum, 2010 1. Gutachter Prof. Dr. Jürgen Schreuer 2. Gutachter Prof. Dr. Ladislav Bohatý Datum der Vorlage 20.10.2010 Datum der Disputation 17.12.2010 “If we knew what we were doing, it wouldn't be research” Albert Einstein This thesis is dedicated to My Love Arti & My sweet ‘n’ cute loving daughter Aditi Abstract In this thesis the elastic properties of two distinct groups of piezoelectric crystals are presented: one is natural tourmaline occurring with a vast variability in chemical compositions with a stable phase over a wide temperature range and hence allowing to examine the influence of chemical composition on its physical properties; while the other is synthetically grown relaxor ferroelectric calcium barium niobate (CBN) exhibiting a ferroelectric-paraelectric phase transition and thus invoking the interest to investigate the variation of elastic properties in both phases as well as in the vicinity of the phase transition. To this end the non-destructive innovative method of resonant ultrasound spectroscopy (RUS) was employed. The full sets of elastic, piezoelectric, dielectric constants and coefficients of thermal expansion of five natural single crystal tourmalines of gem quality have been determined between 100 K and 903 K. The main influence of Li and Fe on elastic, piezoelectric and dielectric properties of tourmalines was studied.
    [Show full text]
  • Global Lithium Sources—Industrial Use and Future in the Electric Vehicle Industry: a Review
    resources Review Global Lithium Sources—Industrial Use and Future in the Electric Vehicle Industry: A Review Laurence Kavanagh * , Jerome Keohane, Guiomar Garcia Cabellos, Andrew Lloyd and John Cleary EnviroCORE, Department of Science and Health, Institute of Technology Carlow, Kilkenny, Road, Co., R93-V960 Carlow, Ireland; [email protected] (J.K.); [email protected] (G.G.C.); [email protected] (A.L.); [email protected] (J.C.) * Correspondence: [email protected] Received: 28 July 2018; Accepted: 11 September 2018; Published: 17 September 2018 Abstract: Lithium is a key component in green energy storage technologies and is rapidly becoming a metal of crucial importance to the European Union. The different industrial uses of lithium are discussed in this review along with a compilation of the locations of the main geological sources of lithium. An emphasis is placed on lithium’s use in lithium ion batteries and their use in the electric vehicle industry. The electric vehicle market is driving new demand for lithium resources. The expected scale-up in this sector will put pressure on current lithium supplies. The European Union has a burgeoning demand for lithium and is the second largest consumer of lithium resources. Currently, only 1–2% of worldwide lithium is produced in the European Union (Portugal). There are several lithium mineralisations scattered across Europe, the majority of which are currently undergoing mining feasibility studies. The increasing cost of lithium is driving a new global mining boom and should see many of Europe’s mineralisation’s becoming economic. The information given in this paper is a source of contextual information that can be used to support the European Union’s drive towards a low carbon economy and to develop the field of research.
    [Show full text]
  • Highly Efficient Generation of Pulsed Photon Pair Using a Bulk Periodically Poled Potassium Titanyl Phosphate
    Highly efficient generation of pulsed photon pair using a bulk Periodically Poled Potassium Titanyl Phosphate Bao-Sen Shi and Akihisa Tomita Imai Quantum Computation and Information Project, NEC Tsukuba Laboratories, ERATO, Japan Science and Technology Corporation (JST) Fundamental Research Laboratories, NEC, 34 Miyukigaoka, Tsukuba, Ibaraki, 305-8501, Japan Abstract In this paper, we demonstrate efficient generation of collinearly propagating, degenerate pulsed photon pairs based on a bulk Periodically Poled Potassium Titanyl Phosphate pumped by an ultrashort pulse laser. Using a single-mode fiber as a spatial mode filter, we detect about 3200 coincidence counts per second per milliwatt pump power. After we consider main losses in our experiment, the inferred coincidence counts are about 1.09×105 per second per milliwatt pump power. This is the very promising for realization of sources for quantum communication and metrology. Keywords: PPKTP, Parametric Down Conversion, Quantum Communication Sources creating the entangled photon pairs are an essential tool for a variety of fundamental quantum mechanical and quantum information experiments. [1-7] At present, the most accessible and controllable source of entanglement is the process of Spontaneous Parametric Down-Conversion (SPDC) in a nonlinear crystal [8,9]. Although a lot of important results have been obtained, but still many experiments like teleportation, swapping suffer from the lower photon-pair production leading to low signal-to-noise ratio and long measurement times. More recently, periodically poled bulk crystals or waveguides were used to generate the photon pair, and experimentally were shown to be very efficient compared to bulk crystals [10-17]. A periodically-poled crystal, like a Periodical-Poled Lithium Niobate (PPLN) or a Periodically-poled Titanyl Phosphate (PPKTP), with an appropriate grating period, permit efficient three-wave mixing at user-selectable wavelengths by the technique of quasi-phase matching (QPM).
    [Show full text]