四倍频Nd：YAG激光在高压氢气中的喇曼频移研究

利用Nd:YAG固体激光器四倍频输出(266nm)在高压H₂中的受激喇曼散射获得多波长的激光输出。当泵浦能量一定时,通过改变H₂压力得到了最佳的能量输出,299nm波长的激光能量为3mJ,341nm波长的激光能量输出为6.1mJ,398nm波长的激光能量输出为2.8mJ,239nm波长的激光能量输出为0.8mJ,同时在477nm,595nm,218nm,200nm波段也有能量输出。     

Stimulated rotational Raman conversion in H2, D2, and HD

Stimulated rotational Raman conversion has been efficiently demonstrated in all three molecular hydrogen isotopes with a 532-nm Q-switched pump source. Optimum gas pressures and pump focusing have been determined. Single pass conversion efficiencies of 80%, 75%, and 65% have been achieved at the first Stokes wavelengths with H₂ , D₂, and HD, respectively. The maximum efficiency is generally limited by further Raman conversion of the initially generated Stokes light. The thresholds were found to increase in the order H₂ 22. The relative thresholds of H₂ and D₂ are reasonably consistent with the calculated steady-state gains based on the population statistics and the linewidth data. Intermediate frequency shifts such as these may be useful by themselves, or in combination with other nonlinear techniques, as methods to achieve specific wavelengths for system applications     

Nd:YAG四倍频激光抽运D2和D2/He受激拉曼散射的实验研究

使用脉冲Nd:YAG四倍频激光抽运充有纯D2气体和D2/He混合气体的拉曼池.实验研究了受激拉曼散射的能量转换效率和能量稳定性与系统主要参量,包括抽运光能量、D2气体压强和加入惰性气体He的关系.实验表明,适量惰性气体He的加入在没有降低一阶斯托克斯散射光(S1,波长:289.04 nm)能量稳定性的前提下,有利于提高其能量转换效率,最大能量转换效率达到22.1%.通过实验分析,得到了受激拉曼散射一阶斯托克斯散射光的能量转化效率和能量稳定性的优化条件.     

KLu(WO4)2crystal as the Raman medium in a diode-pumped passively Q-switched Nd:YAG laser

A diode-pumped passively Q-switched Nd:YAG/KLu(WO 4 ) 2 (KLW) Raman laser is presented for the first time. As high as 1.89 W average output power is obtained at the pump power of 15.7 W with the pulse repetition frequency (PRF) of 27.2 kHz, and the corresponding diode-to-Stokes conversion efficiency is 12.0%. The highest pulse energy of 84.0 μJ is obtained. The obtained average output power and pulse energy are much higher than the previously reported results of diode-pumped passively Q-switched Raman lasers.     

Third harmonic generation of Nd:YAG laser light in periodicallypoled LiNbO3 waveguide

The authors propose and first demonstrate an LiNbO₃ waveguide device with cascading quasi-phase-matched second harmonic generation and quasi-phase-matched sum-frequency generation for generation of a third harmonic wave. Ultraviolet light of 355 nm wavelength, which was the shortest value ever reported for LiNbO₃ waveguide wavelength-convertors, was obtained with Nd:YAG laser light     

基于金纳米笼和MoS2的1 123 nm被动调Q Nd: YAG激光器

采用电流置换反应成功制备了金纳米笼溶液并首次验证了其在1123 nm处的非线性饱和吸收特性,作为对比,同样制备了MoS₂饱和吸收体。分别将金纳米笼和MoS₂作为饱和吸收体,实现了中心波长为1 123 nm的Nd: YAG激光器的调Q运转。在MoS₂为饱和吸收体的调Q激光器中,当泵浦功率为6.81 W时,得到的最大平均输出功率为208 mW,最短脉冲宽度为412 ns,最大脉冲重复率为233 kHz。在金纳米笼为饱和吸收体的调Q激光器中,当泵浦功率为6.04 W时,得到的最大平均输出功率为221 mW,最短脉冲宽度为253 ns,最大脉冲重复率为326 kHz。与MoS₂调Q激光器的实验结果相比,金纳米笼调Q激光器获得的输出功率和效率更高,脉冲宽度更窄,重复率更高。结果证明了金纳米笼在近红外波段激光器中用作饱和吸收体的巨大潜力。     

Half watt average power at 25 kHz from fourth harmonic of Nd:YAG

A half watt of 266 nm radiation has been generated at a pulse rate of 25 kHz by using KD*P and KTP crystals to frequency quadruple a CW-pumped, acoustoopticQ-switched Nd:YAG laser.     

670 nm Nd:YAlO3/LBO腔内倍频激光器

报道了670nmNd:YAlO3/LBO腔内倍频激光器。通过计算分析光学谐振腔参数,设计了较佳的谐振腔参数,在抽运平均功率为1664W时获得了1.2W的670nm激光输出。     

Internally folded Nd:YAG and Nd:YVO4 lasers pumped bylaser diodes

An efficient, scalable, diode-pumped Nd laser design is reported. The gain element can be longitudinally pumped along five separate axes and is relatively simple to fabricate. Both Nd:YAG and Nd:YVO₄ gain media were evaluated. Using five single-stripe laser diodes to pump the Nd:YAG, 3.94 W of absorbed power produced 2.1 W CW at 1.06 μm. The slope efficiency was 54 percent and the output was TEM₀₀. The threshold power was 40 mW. No evidence of thermal saturation was observed up to the maximum pump power. Repetitively Q-switched operation is also reported. The maximum output power for Nd:YVO₄ obtained with 2.9 W of pump power was 1.3 W. The slope efficiency was 47 percent     

Nd:YAG四倍频激光抽运氘后的拉曼效应及其在激光雷达中的应用

利用 Nd:YAG四倍频激光抽运氘气 (D2 )的受激拉曼效应 ,获得一阶斯托克斯 (Stokes)波长2 89nm。通过改变拉曼介质 D2 气压与抽运光能量 ,获得了一阶斯托克斯输出的较佳条件。该波长与 Xe Cl准分子激光波长 30 8nm采用差分吸收方法 ,建立了用于对流层臭氧探测的激光雷达 ,并初步获得了对流层大气臭氧的垂直分布及其时间变化特征。     

High power, CW single-frequency, TEM00,diode-laser-pumped Nd:YAG laser

255 mW of 1.06 μm, CW, single-longitudinal-mode, TEM₀₀ output has been obtained by end-pumping a twisted-mode cavity Nd:YAG laser with a 1 W diode laser. The key elements of the laser are two λ/4 waveplates (zero-order) placed at both ends of the laser crystal (Nd:YAG, φ3×8 mm). The fast axes of the waveplates are rotated by 90° with respect to each other and rotated by 45° with respect to an intercavity Brewster polariser. In addition, one of the waveplates acts as a resonator and mirror and input coupler for the pump radiation     

高功率BNN倍频连续YAG激光器

以铌酸钡钠置于Nd:YAG腔内,采用温度匹配,进行了连续倍频激光的研究,获得0.53微米输出功率达瓦级水平,最高可达2.5瓦以上。     

LD泵铺Nd：YVO4／Cr：YAG被动调Q绿光激光器

报道了一种LD近贴泵浦、KTP晶体腔内倍频的Nd:YVO4/Cr:YAG结构高重复频率被动调Q绿光激光器。在注入泵浦功率为750mW时,得到平均功率86mW、脉冲宽度26.6ns、重复频率79.2kHz、峰值功率41.1W的被动调Q脉冲绿光输出。     

Nd: YVO44与Nd: YAG主动调Q脉冲参数模拟

利用调Q速率方程, 确定了最优输出耦合反射率, 最大脉冲能量, 最大峰值功率和脉冲宽度与无量纲变量z的关系, 并分析了谐振腔往返损耗、谐振腔增益和反转衰减因子分别对Nd:YVO44与Nd:YAG调Q脉冲参数的影响。结果表明: 最优输出耦合反射率和脉冲宽度随谐振腔往返损耗的增大而减小, 最大脉冲能量和最大峰值功率受反转衰减因子的影响很大, 并随反转衰减因子的增大而减小。通过确定z值可以将调Q脉冲参数具体化。     

稳定腔偏振抽取单横模Nd:YAG激光器

将振荡与放大光束分离,使其分别抽取工作物质不同部位的贮能,可以获得较高功率和效率,也降低了对工作物质光学均匀性的要求。     

波长锁定878.6 nm LD调制泵浦Nd: YVO4自拉曼激光器

报道了一款基于调制共振泵浦技术的Nd:YVO₄自拉曼激光器。针对全固态自拉曼激光器中热效应严重导致的激光器输出功率及光光效率普遍偏低的问题,合理地将共振泵浦技术和调制泵浦技术相结合,实现了激光器的有效热管控,缓解了激光器的热效应,提高了泵浦上限,从而实现了激光器输出功率和光光效率的大幅提高。当泵浦源的调制频率为10 kHz、占空比为40%、平均泵浦功率为30 W、声光Q开关的调制频率为100 kHz时,获得了最大平均功率为8.57 W的1176 nm斯托克斯光输出,相应光光转换效率28.6%。相较于相同泵浦功率的连续泵浦机制下的实验结果,斯托克斯光平均输出功率提高了42%,光光效率提高了8.5%。实验结果表明:共振泵浦和调制泵浦技术相结合的方式可以有效缓解热效应,提高泵浦功率上限,从而提高自拉曼激光器的输出功率和光光效率。     

End-pumped Nd:LaF3 and Nd:LaMgAl11O19 lasers

Nd:LaF₃ and Nd:LaMgAl₁₁O₁₉ (LMA) are promising candidates for pulsed diode-laser-pumped lasers because they have relatively long upper state lifetimes and large absorption bandwidths compared to other Nd³⁺ doped materials. Crystal growth of LMA and the spectroscopic properties of both materials are described. Continuous-wave (CW) end-pumped lasers have been demonstrated in these materials using a Ti:Al₂O₃ laser to simulate the diode-laser pump source. Slope efficiencies of 47% for Nd:LaF₃ and 32% for Nd:LMA were obtained. The results for Nd:LaF₃ are typical for end-pumped, CW, Nd³⁺ lasers; the lower slope efficiency for Nd:LMA is attributed to excited-state absorption     

LDA侧面泵浦1319nm/1338nm双波长激光器的研究

使用最大泵浦功率为600 W的LDA侧面泵浦组件,并采用布儒斯特偏振片以及同时优化全反镜和输出镜透过率两种方法,获得了功率基本相等的1319 nm/1338 nm双波长激光输出。在连续输出时,获得30 W的输出功率,利用声-光Q开关调Q输出,在重复频率为4 kHz时,单脉冲能量为6 mJ,脉冲宽度为237 ns,峰值功率为25 kW。     

Reliability of a connected-(r1, s1)-or-(r2, s2)-or-..-or-(rk, sk)-out-of-(m,n): F lattice system

A (linear or circular) connected-(r₁, s₁)-or-(r₂, s₂)-or-^{. .}-or-(r_k, s_k)-out-of-(m, n): F lattice system is the (linear or circular) (m, n)-lattice system if the system fails whenever all components in a connected-(r₁, s₁)-submatrix or all components in a connected-(r₂, s₂)-submatrix or ^{. .} or all components in a connected-(r_k, s_k)-submatrix fail. This paper presents a recursive algorithm for the reliability of the (linear or circular) connected-(r₁, s₁)-or-(r₂, s₂)or-^{. .}-or-(r_k,s_k)-out- of-(m, n):F lattice system. The recursive algorithm requires time and time in the linear case and the circular case, respectively Furthermore, we can reduce the more computing time in the statistically independent and identically distributed case or considering some special systems. Especially, the closed formula is given for the reliability of the linear connected-(2, 1)-or-(1, 2)-out-of-(m, 2): F lattice system in the statistically independent and identically distributed case.     

长脉冲非偏振准分子激光在H_2中的受激喇曼散射

实验研究了X射线预电离XeCl准分子激光器在氢气中的受激喇曼散射。用光电管观察到S_1、S_2和S_3斯托克斯线输出。对受激喇曼散射导致光束发散角减小和脉宽变窄进行了理论分析。