低对称晶体GdCa_4O(BO_3)_3电光系数的测量

用干涉法测量了低对称晶体 Gd Ca4 O(BO3) 3的全部电光系数。为了分离测量交叉电光系数 γ51 ,γ53,γ4 2和γ6 2 ,采用了新的样品趋向。测量结果为 :γ1 1 =0 .4 pm / V ,γ2 1 =0 .5 pm/ V,γ31 =0 .6 pm / V,γ1 3=0 .1pm/ V,γ2 3=0 .4 pm / V,γ33=2 .0 pm/ V,γ51 =0 .7pm / V ,γ53=1.5 pm / V,γ4 2 =0 .5 pm/ V,γ6 2 =0 .8pm / V .     

低对称晶体YCa_4O(BO_3)_3电光系数的测量

用于涉法测量了低对称晶体YCa4O(BO3)3的全部电光系数,为了分离测量交叉电光系数γ51, γ53, γ42,和 γ62,采用了新的样品趋向,测量结果为:γ11=0.6, γ21=0.4, γ31=0.3, γ13=0.3, γ23=0.2, γ33=2.26, γ51=0.9, γ11=0.6, γ11=0.6, γ53=4.1, γ42=0.8, γ62=0.4×10-12m/V。     

泰曼干涉法测量晶体的电光系数

本文报道用泰曼干涉仪通过同时记录干涉光强度和分束前光强度的方法来测量晶体的电光系数的测量结果.     

一种简单和高灵敏度测量晶体电光系数的方法——比较法

在正交偏光干涉实验装置中,用DKDP晶体的电光效应补偿其它晶体电光效应所引起的光程变化,测量晶体电光系数相对于DKDP晶体γ63的数值,提出了一种简单和高灵敏度测量晶体电光系数的方法。     

干涉法测量Zn(SCN)_2·2H_2O晶体的压电系数和电光系数

用干涉法首次测量了Zn(SCN)_2·2H_2O晶体的全部压电系数和电光系数。结果为:d_(14)=-8.8,d_(25)=-15.8,d_(36)=1.2(×10~(-12)C/N);γ41=4.5,γ52=6.4,γ63=0.8(×10~(-12)m/V)。     

RbTiOAsO4(RTA)晶体的电光性能

测量了ＲｂＴｉＯＡｓＯ４（ＲＴＡ）晶体的电光系数、介电常数和交流电导率,结果为：电光系数γ１３＝１０．８,γ２３＝１７．３,γ３３＝４０．０,γ５１＝１２．３,γ４２＝１４．６ｐｍ／Ｖ;介电常数ε１１＝ε２２＝１２,ε３３＝２１;交流电导率σｃ＝３．６×１０－８ｓ／ｃｍ。结果表明ＲＴＡ晶体波导调制器的品质因子ｎ７γ２／ε比ＫＴＰ晶体高１５％,但是其交流电导率比ＫＴＰ晶体小了两个数量级。这些性能使ＲＴＡ晶体有希望应用于波导调制器和其它电光器件。     

Hg（C4H8N2S）3Cl2晶体压电系数的测量

本文测量了Hg(C_4H_8N_2S)_3Cl_2晶体的压电系数,结果为:d_(33)=3.2,d_(31)=-0.2, d_(22)=2.9,d_(15)=3.3×10~(-12)C/N.     

β—BBO晶体的电光性能

用干涉法测量了β－ＢＢＯ晶体的电光系数：γ２２＝２．６，γ３３＝０．２３，γ３１＝０．２５，γ５１＝－３．５×１０－１２ｍ／Ｖ。结果表明如果在Ｙ方向加电场，Ｚ方向通光，β—ＢＢＯ晶体可能制作成有应用价值的光开关。     

GdCa4O(BO3)3晶体电弹常数的测量

首次测量了GdCa 4O(BO3)3晶体的全部介电常数、压电应变常数和部分机电耦合系数.     

Improved second-harmonic generation by selective Yb ion doping in anew nonlinear optical crystal YCa4O(BO3)3

We describe experiments characterizing a new nonlinear optical crystal, YCa₄O(BO₃)₃ (YCOB). This crystal has a number of advantages over other commonly available nonlinear optical crystals. It has a higher nonlinear coefficient than KDP, can be fabricated to large sizes (~3-in diameter, 8-in length), and has a high damage threshold. Moreover, this new nonlinear optical crystal is nonhygroscopic, has good optical quality and mechanical properties, allowing easy optical polishing. This crystal, YCa₄ O(BO₃)₃, commonly termed YCOB, is one of a family of new nonlinear crystals, the oxyborates, that include RECa₄O(BO₃)₃ (RE=La³⁺, La ³⁺, Y³⁺, Sm³⁺, Gd³⁺, Er³⁺, and Nd³⁺). In this paper, we also successfully demonstrate a technique for improving the nonlinear optical properties of this crystal. This technique, ion substitution, has previously had limited success with other crystal hosts. However, the inclusion of yttrium in YCOB provides the opportunity to exploit this technique. Yb³⁺, which has larger mass, but approximately the same atomic size as Y³⁺ can be substituted into the crystal structure without introducing stress and nonuniformities. A systematic investigation of the linear and nonlinear characteristics of several crystals doped with various levels of Yb demonstrate that selective substitution of Yb in YCa₄O(BO₃)₃ improves the second-harmonic conversion efficiency by increasing the optical nonlinearity     

Er_xY_(1-x)Al_3(BO_3)_4晶体的生长及性质

研究了助熔剂法合成Er_xY_(1-x)Al_3(BO_3)_4(EYAB)晶体的工艺;对该体系的物相进行了差热和X-射线分析,确定了K_2Mo_3O_(12)及EYAB相的生成温度得到不同组成的EYAB晶体;观察了晶体缺陷,测定了晶体学参数及热稳定性。     

低对称晶体YCa4O(BO3)3电光系数的测量

用于涉法测量了低对称晶体YCa     

硼酸铝钕[NdAl_3(BO_3)_4](NAB)的脉冲激光特性

本文报道了我所生长的大尺寸硼酸铝钕晶体的脉冲激光特性。当用氙闪光灯泵浦时,φ3.2mm×23.7mm的NAB激光棒,最大激光输出为每个脉冲422mJ。对于φ1.8mm×2.4mm的激光棒,激光阈值为67mJ。激光输出为线性偏振光,波长1.063μm。用BDN染料片调Q时,φ1.2mm×8.4mm的NAB棒激光单脉冲宽度为8ns,光束发散度为2mrad。     

High-Power Laser Performance of Yb:YAl3(BO3)4 Crystals Cut Along the Crystallographic Axes

High-power continuous-wave laser operation near 1 mum was demonstrated at room temperature with c-cut and a-cut Yb:YAl₃(BO₃)₄ crystals end-pumped by a fiber-coupled diode laser. Using a 2-mm-thick c-cut crystal, 10.6 W of output power was generated with an optical-to-optical efficiency of 65% and a slope efficiency of 72%. The complex polarization state of the generated laser radiation was also studied. With a 2-mm-thick a-cut crystal, sigma-polarized laser oscillation was obtained, producing a maximum output power of 8.1 W; the optical-to-optical and slope efficiencies were 56% and 61%, respectively. Complete absorption and emission cross section spectra of the Yb:YAl₃(BO₃) ₄ crystal were also derived, revealing very strong anisotropy of the spectroscopic properties     

Luminescence properties of Ca4GdO(BO3)3:Eu in ultraviolet and vacuum ultraviolet regions

The luminescent properties of Ca₄GdO(BO₃)₃:Eu³⁺ were investigated under excitation of UV and VUV light. Separate two broad bands at around 259 and 184 nm were observed in the excitation spectrum of Ca₄GdO(BO₃)₃:Eu³⁺. These peaks were assigned to the charge transfer transition of Eu³⁺-O²⁻ and Gd³⁺-O²⁻, respectively. Owing to the favorable spectral position in their broad intense excitation band, Eu³⁺ ions show a intense emission under 258 nm excitation in Ca₄GdO(BO₃)₃:Eu³⁺. This spectral position was determined by the free oxygen ions O (1). Ca₄GdO(BO₃)₃ doped with Eu³⁺ ion seems to be a preferable candidate as red lamp phosphor. On the other hand, a weak band with a maximum at about 184 nm was observed below 200 nm in the excitation spectrum of Ca₄GdO(BO₃)₃:Eu³⁺. This phosphor do not emit effectively under the 147 nm excitation. This unfavorable profile was also due to the O (1) ions, which played a role to the shifting towards the lower energy sides. The luminescence of Eu³⁺ ions in Ca₄GdO(BO₃)₃ was somewhat different from that observed in the other borates phosphors, but resembled to those observed in the oxide phosphors (e.g. Gd₂O₃, Y₂O₃ and Gd₂SiO₅). Such behavior was recognized by the detailed analysis of crystallographical surroundings around activator.     

Theoretical and experimental investigations of a diode-pumpedquasi-three-level laser: the Yb3+-doped Ca4GdO(BO3)3 (Yb:GdCOB) laser

We present a theoretical and experimental analysis of a diode-pumped Yb³⁺-doped Ca₄GdO(BO₃)₃ (Yb:GdCOB) laser. A new model for a diode-pumped quasi-three-level laser is described. The effects of absorption saturation, temperature profile, and the beam quality M² factor of the pump diode have been taken into account, for the first time to our knowledge. We have obtained a good agreement between experimental measurements and theoretical calculations with two different pump wavelengths, 902 and 976 nm. Our model has given good predictions of the laser performances for different crystal temperatures and different M² factors of the pump beam. As much as 440 mW of output power (at 1082 nm) have been achieved for 640 mW of absorbed pump power at 976 nm, corresponding to one of the highest slope efficiencies (81%) ever obtained with Yb-doped lasers     

Nonlinear optical properties ofK2La(NO3)5.2H2O and K2Ce(NO3)5.2H2O

The harmonic generating properties of potassium lanthanum nitrate (KLN) and potassium cerium nitrate (KCN) are described. These crystals have much larger nonlinear coefficients than potassium dihydrogen phosphate (KDP) and are nearly noncritically phase matched at room temperature for Type I frequency doubling of 1.064-μm light, and for Type II doubling of light near 0.95 μm. Thus, these crystals are useful for generating blue-green light by frequency doubling high-power near-infrared lasers. The crystal growth of KLN and KCN are described by the three component phase diagrams. Crystallographic data for KCN that confirms its structural similarity to KLN are presented. The optical absorption spectra of the two materials are discussed, and the linear refractive indexes are given