顶部籽晶法生长大尺寸CsLiB6O10晶体

以高纯硼酸、碳酸锂和碳酸铯为原料,摩尔比硼酸:碳酸锂:碳酸铯=11:1:1,采用顶部籽晶法,生长出尺寸为65 mm×22 mm×12 mm CsLiB6O10(CLBO)单晶,探讨了影响CLBO晶体生长的因素.对生长出的CLBO晶体的相关光学性质进行了研究.CLBO晶体的光学均匀性为3.6×10-5/cm,透过光谱表明该晶体的透光范围为185 nm到2790 nm,其紫外吸收边低于185 nm;用Maker干涉条纹测定了CLBO晶体的非线性光学系数为:d36(CLBO)=1.8d36(KDP).     

非线性光学晶体CsB3O5研究进展

非线性光学晶体CsB3O5(CBO)具有大的非线性光学系数、优秀的紫外波段透过能力和高的抗光损伤阈值,在紫外高功率密度全固态激光系统的频率转换方面展现出良好的应用前景。本文综述了CBO晶体的研究概况,报道了高质量CBO晶体生长、折射率温度系数、热学性能及278 nm紫外激光输出的最新研究结果。     

CLBO单晶生长及性能研究

CsLiB₆O₁₀(简称CLBO)是一种性能优良的紫外非线性光学晶体,特别适用于四倍频(266 nm)和五倍频(210 nm)的紫外大功率激光。本文采用顶部籽晶法成功生长出尺寸为120 mm×112 mm×62 mm的CLBO晶体,晶体外观完整,无开裂、散射等宏观缺陷。由该晶体切出五倍频CLBO晶体元件,对其进行了紫外-可见-近红外透过率、光学均匀性、弱吸收性能表征,结果显示,210～1 800 nm的平均透过率超过90%,光学均匀性为3.8×10^-5,1 064 nm弱吸收为90×10^-6 cm^-1,表明该晶体紫外区透过率良好,光学均匀性高,弱吸收低,为后续相关激光应用研究奠定了基础。     

CLBO晶体生长与紫外倍频性能研究

CLBO晶体是一种性能优良的新型激光紫外倍频晶体材料,本文采用改进的顶部籽晶法生长出大尺寸、高光学质量的CLBO晶体.用尺寸为6mm×5mm×10mm的CLBO四倍频样品测量了晶体对Nd:YAG,1064nm四倍频的紫外倍频性能,266nm激光输出功率达到780mW.针对CLBO晶体的潮解开裂问题,在CLBO倍频器工作和存放时,采用恒温加热套管保护,有效地防止了晶体的潮解开裂.     

新疆理化所提出一种基于模拟的使非线性光学晶体材料相匹配区间蓝移的方案

非线性光学晶体是通过频率转换拓宽固态激光器输出波段的关键材料。随着激光微加工,激光通讯和现代科学仪器的持续发展,对紫外/深紫外非线性光学晶体的需求日益增加。但是,很多拥有宽的紫外透过范围和大的倍频效应的晶体因其双折射无法满足深紫外相匹配而无法输出深紫外激光。     

福建物构所在拓宽非线性光学晶体的相配匹配范围研究中获进展

正探索发现性能优异的深紫外非线性光学晶体一直是功能材料研究领域的热点。三硼酸锂(LBO)晶体是中国科学院福建物质结构研究所发现的一种优秀的紫外无机非线性光学晶体,具有生长晶体尺寸大、光学质量好、透光范围宽、倍频系数大和损伤阈值高等优点,是目前应用于高功率固体激光器件的最佳倍频晶体材料。但是由于LBO晶体的双折射率偏小,使之难以通过相位匹配技术直接倍频产生深紫外相干光源。尽管     

LBO晶体Ⅱ类相位匹配走离角及互作用长度的计算

从非线性光学理论出发,数值计算了LBO晶体Ⅱ类相位匹配1064 nm光波倍频的走离角及互作用长度.在全匹配角范围内,1064 nm慢、快两光间夹角的范围是0~1.0°,θ≈0°.φ≈90°时,夹角为0°;θ≈45°,φ≈55°时,最大夹角约为1.0°.慢、快两基频光光斑线度相同时,波矢沿θ≈0°,φ≈88°方向入射时,其互作用长度最大.     

福建物构所深紫外非线性光学晶体材料研究获新进展

<正>深紫外激光具有波长短、光子能量高等优点,因而在高分辨率成像、光谱应用、微细加工等诸多领域具有重要的应用价值,利用深紫外非线性光学晶体进行变频是获得深紫外激光的主要手段。优良的深紫外非线性光学晶体既要具有大的非线性光学效应,又要具有短的紫外吸收边,而这两种性能在某种程度上是相互冲突的,这就需要在两者之间达到一个微妙的平衡。目前,已知的深紫外非线性光学晶体几乎都是硼酸盐,基     

红外非线性光学晶体材料AgGaGeS4激光实验参数的模拟计算

在小信号近似下,对红外非线性光学晶体AgGaGeS4的非线性性质进行研究.模拟计算了钛宝石0.8 μm,Nd:YAG 1.064 μm泵浦下,Ⅰ类AgGaGeS4-OPO在XZ调谐面上的相位匹配情况,晶体波长调谐范围可达0.90～11.4 μm,调谐角19.7～59.3°,有效非线性系数随匹配角增大而逐渐降低.另外也计算了晶体激光倍频波波长和相位匹配角的关系,晶体调谐角度范围0～62°,波长1.5～10.6 μm,同时对倍频允许角及非临界准相位匹配(NCPM)下的情况也进行了探讨.所得结果可预测其非线性性质,并对探索AgGaGeS4晶体用于特定波长激光器,设计新波段提供了理论依据.     

KBe2BO3F2晶体非共线匹配倍频研究

根据氟硼铍酸钾(KBe2BO3F2,简称KBBF)晶体最新的色散方程以及非共线匹配的条件,采用FORTAN语言变精度数值计算方法,以YAG激光器1064 nm波长入射为例,数值计算了KBBF晶体的Ⅰ类非共线倍频相位匹配角、有效非线性系数和允许角。计算结果显示:在第一象限内,存在两个匹配方向,第一个匹配方向对应的基频o光和倍频e光的匹配角范围为19.00°～89.50°,18.08°～55.20°,20.78°～72.60°;第二个匹配方向对应的基频o光和倍频e光匹配角范围分别为19.00°～55.00°,25.07°～89.75°,22.03°～72.38°。第一组匹配方向的相位匹配角范围和相应的有效非线性系数比第二组匹配方向的大,第一组匹配方向对应的允许角比第二组匹配方向小。因此非共线相位匹配结构下KBBF晶体的Ⅰ类倍频应该采用第一组匹配方向。     

新型中、远红外波段非线性光学晶体磷化锗锌

中、远红外波段黄铜矿类半导体晶体磷化锗锌(ZnGeP2,ZGP)非线性系数、热导率、光损伤阈值高,在中、远红外波段的频率转换方面有广阔的应用前景,特别是其非线性系数是KDP的160倍,是已知非线性光学晶体中最高者之一.该晶体的生长及其应用研究正在逐渐引起各国政府和科研人员的高度重视,并成为材料与光电子(激光)领域的研究热点之一.本文全面综述了该晶体的物性与电光性能,以及多晶原料的合成与单晶的生长方法和其应用前景.     

用DSC法测定BBO、LBO和CLBO晶体的恒压比热容

本文用差示扫描量热法(DSC)测定了非线性光学晶体BBO、LBO和CLBO的恒压比热容,计算了在220～420K温度范围内每间隔10K的焓差值和熵差值.有关误差分析表明,该测试方法是有效的,并可用于其它晶体的恒压比热容的测量.     

B3O7基团型硼酸盐非线性光学晶体研究进展

以B3O7基团为基本结构单元的硼酸盐非线性光学晶体LiB3O5,CsB3O5,CsLiB6O10具有紫外透过波段宽,非线性光学系数较大,光损伤阈值高的共同特性,有利于紫外波段激光频率变换,本文综合叙述了B3O7基团型硼酸盐非线性光学晶体的研究进展。     

Water diffusion into a silica glass optical fiber

The diffusion coefficient and solubility of water in silica glass optical fiber cladding were measured in the temperature range of 600-800 °C and were compared with the corresponding values of bulk silica glasses. It was found that the diffusion coefficient was slightly lower and the solubility was appreciably higher in optical fiber, especially at low temperatures, compared with those in bulk silica glasses. The observed trend was consistent with the expected effect of fictive temperature.     

Substrate temperature effect on the optical properties of amorphous Sb2S3 thin films

Sb₂S₃ amorphous thin films were prepared by thermal evaporation of corresponding powder on thoroughly cleaned glass substrates held at temperature in the range 300‐473 K. X‐ray diffraction and atomic force microscopy have been used to order to identify the structure and morphology of surface thin films. The optical constants of the deposition films were obtained from the analysis of the experimental recorded transmission data over the wavelength range 400‐1400 nm. An analysis of the absorption coefficient values revealed an optical indirect transition with the estimation of the corresponding band gap values. It was found that the optical band gap energy decrease with substrate temperature from 1.67 eV at 300 K to 1.48 eV at 473K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

A Study of a Ferroelectric Liquid Crystal Using Second Optical Harmonic Generation

The phase-matched generation of the optical second harmonic was investigated in the chiral smectic C* phase of a classical ferroelectric liquid crystal (DOBAMBC). The phase-matching was achieved either by incidence angle or by temperature tuning. The temperature behaviour of the second order nonlinear susceptibility was studied.     

Growth,optical and thermal studies of nonlinear optical L‐arginine perchlorate single crystals

A potentially useful semiorganic nonlinear optical (NLO) material, L‐arginine perchlorate, has been synthesized and bulk crystals have been grown by slow cooling technique. The grown crystals were characterized by single crystal X‐ray diffraction, UV‐Vis‐NIR spectroscopy, FT‐IR, thermal analysis and SHG measurements. The grown crystals were thermally stable upto 153°C and exhibit SHG efficiency of about 0.17 with respect of Urea. The etching studies have been carried out on the grown crystal. LAPC has good optical transmission not only in the visible range, however, also in the near UV part of the spectra and hence it is a potential material for nonlinear frequency conversion. The refractive index was measured by the Brewster's angle method. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Thermal lens and Z-scan measurements: Thermal and optical properties of laser glasses – A review

In this paper, the application of thermal lens and Z-scan techniques to the study of the thermo-optical and spectroscopic properties of solid-state laser glasses is described. The theoretical basis for quantitative measurements of thermal diffusivity and conductivity, temperature coefficient of the optical path length change, heat efficiency, fluorescence quantum efficiency, losses mechanisms (Auger upconversion and concentration quenching) and the line shape of the nonlinear refractive index are presented and discussed. The electronic contribution to the nonlinearity was investigated using the Z-scan technique in the time-resolved mode. The measurements were performed spectroscopically, allowing the determination of the line shapes of real and imaginary parts of the nonlinear refractive index, n₂, in resonance with laser transitions. The results were interpreted by considering resonant and nonresonant contribution to n₂. The magnitude of electronic and thermal contributions to the refractive index changes in solid-state laser glasses were also compared, and the thermal properties as a function of the temperature in the range of 20 up to 600 K are presented.     

Effektive Masse und Beweglichkeit der Löcher in p-ZnSiAs2

The density of states effective mass of the valence band and impurity parameters in p-ZnSiAs₂ were determined from the temperature dependence of the Hall coefficient. The density of states effective mass of holes in ZnSiAs₂ is (0.21 ± 0.03) m₀. Three acceptor levels located at 15 meV, 40 meV and 200 meV upper the valence band edge were found. A mobility analysis was carried out taking into account the interaction of the current carriers with the large number of longitudinal optical branches existing in chalcopyrite structure. The experimental values are in good accordance with the theoretical mobility curves in the temperature range from 77 K up to 600 K.