激光二极管端面抽运的1.34μm Nd:YVO4平凹腔型激光器

理论上分析了端面抽运的1.34μm Nd:YVO₄平凹腔型激光器的各项参数；实验 上实现了LD端面抽运的1.34μm Nd:YVO₄平凹腔型激光器的运转. 关键词： 固体激光 4晶体')" href="#">Nd:YVO₄晶体 平凹腔     

BBO四倍频全固态Nd:YVO4紫外激光器

报道了用BBO晶体对激光二极管抽运Nd:YVO₄晶体声光调Q产生的1.064μm激光 进行四倍频,实现平均功率为63mW准连续波266nm紫外激光运转,重复频率为12.5kHz、单 脉冲能量5μJ、峰值功率达252W,绿光-紫外光转换效率达11%. 关键词： 266nm紫外激光 四倍频 全固态     

高效率LD端面抽运准连续355 nm激光器

报道了一台激光二极管（LD）端面抽运Nd：YVO₄晶体腔内倍频和腔外和频相结合的声光调Q准连续355 nm 紫外激光器。采用LD端面抽运双侧翼键合YVO₄基质的Nd：YVO₄晶体,在腔内置入Ⅰ类相位匹配的LiB₃O₅（LBO）晶体进行倍频实现1 064 nm和532 nm双波长准连续激光输出,通过消色差透镜将双波长激光聚焦耦合到Ⅱ类相位匹配的LBO 晶体中进行和频,并采用双向和频光路,获得了高效率、高光束质量、高重复频率的准连续355 nm 紫外激光输出。在抽运功率为28.6 W、重复频率为20 kHz时,355 nm激光最大输出功率4.2 W,脉宽为20.6 ns,光-光转换效率为14.7%,激光器光束质量因子M_x²和M_y²分别为1.29和1.23。     

端抽运Yb3+:YVO4激光准三能级理论模型研究

立足于Yb离子能级结构、谐振腔增益损耗和布居数分配情况, 利用爱因斯坦辐射理论和速率方程理论, 建立了适合Yb³⁺离子激光的准三能级理论模型. 该模型引入有效腔长增益贡献因子对腔内光强进行了从头计算, 获得了阈值方程. 利用此模型与Yb激光的实验结果相比较, 发现有效腔长对增益的贡献可以改变腔内损耗和粒子数反转的概率, 也继而影响激光阈值和输出功率效率. 应用于LD端抽运Yb³⁺:YVO₄激光实验中, 在971 nm LD抽运, 有效晶体长度 L=1 mm, 输出镜透过率对激光波长1016 nm为1%条件下, 获得阈值为1.1 W; 有效晶体长度L=2 mm, 输出镜透过率为10%条件下, 阈值获得为3.9 W. 关键词： 3+:YVO₄')" href="#">Yb³⁺:YVO₄ 准三能级模型 有效腔长增益贡献因子     

紧凑型激光二极管抽运全固态355 nm连续波紫外激光器

报道了一台激光二极管端面抽运Nd:YVO₄晶体内腔三倍频355 nm激光连续输出的全固态紫外激光器.激光腔采用紧凑型简单凹平直腔,腔长仅为70 mm.利用两块LBO晶体进行腔内倍频、和频,当注入抽运功率为2527 W时,获得最大功率为306 mW的355 nm连续波输出,光光转换效率为012％,输出功率短期不稳定性为53%,355 nm激光输出光束质量良好.通过采用内腔倍频技术和设计合理的腔参数,实现了中小功率连续输出的全固态紫外激光器的小型化、便携化,进一步拓宽了紫外激光器 关键词： 激光二极管端面抽运 内腔三倍频 连续波 355 nm激光     

激光二极管端面抽运Nd∶YVO4晶体连续输出板条激光器研究

报道了利用激光二极管列阵端面抽运Nd∶YVO₄混合腔板条激光器连续波输出的实验结果,获得近衍射极限的60 W连续激光输出. 实验证明两种晶体输出功率相当,低掺杂浓度的Nd∶YVO₄晶体更有利于得到近衍射极限的高功率输出,但同时对冷却水温度的变化也较敏感. 关键词： 激光二极管端面抽运 板条激光器 混合腔     

LD抽运Nd:YVO4晶体中的上转换及其影响

对激光二极管抽运下Nd:YVO₄晶体中的上转换发光做了测量与分析,发现对应⁴G_7/2能级向下跃迁的上转换发光的主导机制为能量传递上转换.接着,对上转换对LD抽运Nd:YVO₄激光器运转的影响进行了理论分析,并特别讨论了上转换对热效应的影响. 关键词： 上转换 固体激光器 热效应     

高稳定输出功率的全固态激光器

介绍了一种高稳定性输出功率的连续LD抽运Nd∶YVO₄全固态532 nm激光器,输出功率为144 mW,采用LD抽运Nd∶YVO₄晶体,KTP晶体腔内倍频方式工作。该激光器采用热电制冷器(TEC)实现对LD、KTP晶体的高精度温控,其温控精度达到±0.1 ℃。建立了LD电流与输出功率的非线性曲线,通过硅光电池检测激光输出功率实现激光功率实时光反馈,采用阈值式PI控制算法进一步降低稳态误差,通过对抽运驱动电流实施反馈控制获得了波动小于±1%的长时间高稳定功率输出。     

Nd:Ca4ReO(BO3)3(Re=Gd,Y)晶体最佳激光、最佳倍频及最佳自倍频方向的确定

介绍了Nd:Ca4ReO(BO3)3(Re=Gd,Y)晶体最佳激光方向、最佳倍频方向的确定.综合考虑激光受激发射截面、抽运光吸收系数、有效非线性系数的各向异性,分析了自倍频性质的空间分布,并就此确定出最佳自倍频方向 关键词： Nd:Ca4ReO(BO3)3(Re=Gd Y)晶体 激光发射 倍频 自倍频     

LD泵浦全固态608.1nm和频激光器

本文报道了一种全固态腔内和频608.1 nm激光器。在激光谐振腔两个分臂中,两支激光二极管分别泵浦Nd: YVO₄和Nd: YAG晶体,分别选择1 342 nm波长(Nd: YVO₄晶体的⁴F_3/2-⁴I_13/2谱线)与1 112 nm波长(Nd: YAG晶体的⁴F_3/2-⁴I_11/2谱线)振荡并进行腔内和频。通过优化谐振腔设计,腔内两个波长获得了较好的模式匹配。在两个分臂的交叠部分,利用LBO I类相位匹配进行和频,获得和频608.1 nm激光输出。实验表明,当Nd: YVO₄与Nd: YAG晶体泵浦功率分别为600和740 mW时,获得了功率为23.8 mW、波长为608.1 nm激光输出,激光输出稳定、噪声低。利用本文提出的和频结构是获得608.1 nm激光输出较为有效的方法。     

A novel orthogonally linearly polarized Nd:YVO4 laser

We presented a novel orthogonally linearly polarized Nd:YVO₄ laser. Two pieces of a-cut grown-together composite YVO₄/Nd:YVO₄ crystals were placed in the resonant cavity with the c-axis of the two crystals orthogonally. The polarization and power performance of the orthogonally polarized laser were investigated. A 26.2-W orthogonally linearly polarized laser was obtained. The power ratio between the two orthogonally polarized lasers was varied with the pump power caused by the polarized mode coupling. The longitudinal modes competition and the corresponding variable optical beats were also observed from the orthogonally polarized laser. We also adjusted the crystals with their c-axis parallele to each other, and a 40.7-W linearly polarized TEM₀₀ laser was obtained, and the beam quality factors were M²_x=1.37 and M²_y=1.25.     

1097 nm Nd:YVO4 self-Raman laser

An acousto-optically Q-switched self-Raman laser emitting at 1097 nm is demonstrated with a c-cut Nd:YVO₄ crystal, using a fiber-coupled 880 nm diode laser as the pumping source. Raman laser performances in concave-plane and plane-plane oscillating cavities are studied and compared. With an absorbed diode power of 12.4 W and a pulse repetition rate of 50 kHz, the highest output power of 1.45 W is obtained from the plane-plane cavity, corresponding to an optical-to-optical conversion efficiency of 11.7%.     

800 mW/1484 nm highly efficient two-cascaded phosphosilicate Raman fiber laser pumped by Nd:YVO4 solid-state laser

Using 1064 nm CW Nd:YVO₄ solid-state laser as a pump, 1-km phosphosilicate fiber and cascaded cavities with two pairs of fiber Bragg grating mirrors for 1239 and 1484 nm, we obtained a CW 800 mW/1484 nm Raman fiber laser (RFL) for an actual incident pump power of about 2 W (Nd:YVO₄ power of 6.90 W). The conversion efficiency is as high as 40%. To the best of our knowledge, this is the highest conversion efficiency of RFL pumped by solid-state laser. The output power instability at 1484 nm in half an hour is less than 3%. In addition, the numerical simulations are also performed. Good agreement between the results of numerical simulation and the results of the experiment has been demonstrated.     

High-efficiency longitudinally-pumped miniature Nd:YVO4 laser

We report on fundamental and intracavity frequency-doubled emission in a miniature Nd:YVO₄ (3×3×1 mm) laser. A maximum slope efficiency of η_s=58.6%, with optical efficiency of η₀=53.0% at 780 mW pump power was realized in a TEM₀₀ output beam. To obtain the optimum pump-beam focusing conditions we applied a new formalism in which the pump-beam propagation in the active medium was described by its M² factor. A good agreement between theoretical predictions and experimental results was observed. In second-harmonic regime, obtained by a KTP crystal, 230 mW green power that corresponds to 54% nonlinear conversion efficiency was reached.     

High-efficiency Nd:YVO4 laser emission under direct pumping at 880 nm

We report a high-efficiency Nd:YVO₄ laser pumped by an all-solid-state Q-switched Ti:Sapphire laser at 880 nm in this paper. Output power at 1064 nm with different-doped Nd:YVO₄ crystals of 0.4-, 1.0- and 3.0-at.% under the 880 nm pumping was measured, respectively. Comparative results obtained by the traditional pumping at 808 nm into the highly absorbing ⁴F_5/2 level were presented, showing that the slope efficiency and the threshold with respect to the absorbed pump power of the 1.0-at.% Nd:YVO₄ laser under the 880 nm pumping was 17.5% higher and 11.5% lower than those of 808 nm pumping. In a 4-mm-thick, 1.0-at.% Nd:YVO₄ crystal, a high slope efficiency of 75% was achieved under the 880 nm pumping, with an optical-to-optical conversion efficiency of 52.4%.     

Continuous-wave intracavity Raman laser at 1179.5 nm with SrWO<Subscript>4</Subscript> Raman crystal in diode-end-pumped Nd:YVO<Subscript>4</Subscript> laser

We report a continuous-wave intracavity Raman laser at 1179.5 nm with a SrWO₄ Raman crystal in a diode-end-pumped Nd:YVO₄ laser. The highest output power of 2.23 W is obtained at the laser diode power of 21.2 W corresponding to the slope efficiency of 17.3% and a diode-to-stokes optical conversion efficiency of 10.5%. The dependence of the Raman laser performance on the pump polarization is also studied. The measured Raman thresholds are about 9.3 and 8.3 W in the diode pump laser power for the a- and b-polarized configurations, respectively. The Raman gain coefficients of the c-cut SrWO₄ crystal for a- and b-polarized pumps are estimated to be about 4.9 and 4.7 cm/GW, respectively.     

Compact efficient 1.5 W continuous wave Nd:YVO4/LBO blue laser at 457 nm

A compact folded three-mirror cavity with length of 100 mm is optimized to obtain high efficient 457 nm laser. When the incident pump power into Nd:YVO₄ is 16.3 W, as high as 1.52 W continuous wave 457 nm blue laser is achieved by LBO intracavity frequency doubled. The optical-to-optical conversion efficiency is greater than 9.3%.     

A comparative study of continuous laser operation on the F3/2-I9/2 transitions of Nd:GdVO4 and Nd:YVO4 crystals

A comparative study of Nd:GdVO₄ and Nd:YVO₄ crystal lasers pumped by a fiber-coupled diode array has been conducted at the ⁴F_3/2-⁴I_9/2 transitions wavelengths of 912 nm and 914 nm, as well as when intracavity frequency-doubled to 456 nm and 457 nm, respectively. At the fundamental wavelength of 912 nm and second harmonic wavelength of 456 nm, maximum output powers from the Nd:GdVO₄ crystal laser were 7.85 W and 4.6 W at a pump power of 29 W. All the results obtained from Nd:GdVO₄ were superior to those of Nd:YVO₄, indicating that Nd:GdVO₄ is a more efficient laser crystal than Nd:YVO₄ for laser operation on the ⁴F_3/2-⁴I_9/2 transitions.     

Efficient and compact intracavity-frequency-doubled YVO4/Nd:YVO4/KTP laser through analysis of the interaction length

In this paper, a stable end-pumped intracavity-frequency-doubled green laser was demonstrated. The interaction length of different pump systems before setting up the experiment was analyzed in order to find out an effective pump system. The experimental results indicate that the pump system in our configuration is beneficial to the efficient CW Nd lasers. A continue-grown composite crystal YVO₄/Nd:YVO₄, with Nd³⁺ concentration doping of 0.3 at.%, is used as laser medium. With an incident pump power of 27.5 W, as high as 7.2 W of CW output power at 532 nm was achieved. The optical-to-optical conversion efficiency of 26.2% was obtained in CW modes with a flat-flat cavity design.     

Continuous-wave diode-laser end-pumped Nd:YVO4/KTP high-power solid-state green laser

A simple folded-cavity used for intracavity frequency-doubled Nd:YVO₄ laser was analyzed by transmission matrix and numerical calculation. We have selected a set of proper cavity parameters which can be used readily by operating at high power levels with low threshold, high efficiency, and wide dynamic operating range. 5.6-W TEM₀₀ green laser has been obtained at a 22-W pumping power and with an optical–optical conversion efficiency of 25.5%.