High-Average-Power Third Harmonic Generation at 355 nm with CsB3O5 Crystal

A 17.7W average power output at 355nm by the third harmonic generation (THG) of 1064nm light has been obtained with the nonlinear optical crystal CsB305 (CBO). The fundamental light source is a diode-pumped Nd:YAG laser with a pulse duration of 70ns and a repetition rate of 7kHz. A CBO crystal cut for type-Ⅱ PM angles is used in the experiment. The THG energy conversion efficiency with CBO is twice as large as that with LBO. As a THG crystal, CBO has better performance than that of LiB305 crystal (LBO).     

参量自注入放大产生皮秒中红外脉冲

首次采用参量自注入放大方法产生了皮秒中红外超短脉冲．该方法的优点是仅使用１块红外非线性晶体，实验装置简单，成本低．入射光源是锁模皮秒Ｎｄ：ＹＡＧ激光器，用来泵浦ＡｇＧａＳ２单晶，经过参量过程辐射３—１０μｍ的皮秒脉冲激光．最大红外脉冲激光输出能量为１４μＪ．     

Beam divergence effects on high power optical parametric oscillation

The beam divergence effects of the input pump laser on a high power nanosecond optical parametric oscillator （OPO） have been numerically simulated. The OPO conversion efficiency is affected due to the angular deviation of real laser beams from ideal phase matching conditions. Our theoretical model is based on the decomposition of the Gaussian beam and assumes each component has a single deviation angle and thus a particular wave vector mismatch. We take into account the variable intensity profile in the spatial and temporal domains of the Gaussian beam, the pump depletion effects for large-signal processes as well as the oscillatory effects of the three waves. Two nonlinear crystals β-BaB2O4 （BBO） and LiB305 （LBO） have been investigated in detail. The results indicate that the degree of beam divergence strongly influences the maximum pump intensity, optimum crystal length and OPO conversion efficiency. The impact of beam divergence is much more severe in the case of critical phase-matching for BBO than in the case of non-critical phase-matching for LBO. The results provide a way to choose the optimum parameters for a high power ns OPO such as the nonlinear material, the crystal length and the pump intensity, etc. Good agreement is obtained with our experimental results.     

阶梯量子阱子带跃迁二次谐波产生的研究

本文理论上利用二能级近似下的传递矩阵法,给出了GaAs/Al_xGa_1-xAs二阶非线性光学系数X_2ω⁽²⁾的解析表达式,通过数值计算,设计了具有较大X_2ω⁽²⁾的阶梯多量子阱(SMQW)结构,其特点是单共振泵浦,实验上验证了该结构确实具有比体材料大3个量级的X_2ω⁽²⁾值,为了提高二次谐波(SHG)的转换效率,我们分别设计了两种新型的实验方案,分别使SHG转换效率较Brewster角入射下大10倍和100倍。     

Highly—Efficient Blue—Light Generation by Intracavity nFrequency Doubling with LiB3O5

We have investigated the generation of highly-efficient blue light in critically type-I phase-matched LiB3O5 (LBO) with intracavity frequency doubling of diode-pumped Nd:YAG laser.A maximum output power of 502 mW at 473 nm blue light was obtained and the overall optical-to-optical efficiency is up to 11.2%.To the best of our knowledge,this is the highest conversion efficiency for 473nm output using a diode pumped Nd:YAG laser through LBO.     

CO_2激光器用的气体发生器

我们在研制气体转换炉工作[1]的基础上,经过改进又制成气体发生器.将它分别用于波导 CO2激光器和 TEA CO2激光器,所得的结果表明,对于采取气体流动方式工作或需要更换工作气体的CO2激光器,如果配备一台气体发生器,就可以由空气,CO2,空气 CO2,N2 CO2等获得多种组分的工作气体     

大尺寸优质三硼酸铋晶体及其蓝光输出

从以顶端籽晶法生长的大尺寸优质三硼酸铋(BIBO)单晶体制备长为5mm的Ⅰ类倍频器件,在准连续Nd：YAG激光器中获得216mW的蓝光输出,转换效率约为三硼酸锂(LBO)晶体的2倍。     

2-μm singly resonant optical parameter oscillator

We experimentally realize a singly resonant optical parameter oscillator （OPO） which operates at the degenerate point of KTiOPOa （KTP） crystal. A thin film plate polarizer （TFP） is used as the output coupler to obtain linearly polarized 2.12 μm laser. A maximum output power of 2.2 W at 2.12 μm is obtained from a near-degenerate, type-II KTP OPO by utilizing a Q-switched diode-pumped Nd：YAG laser operating at 5 kHz.     

A Continuous-Wave Diode-Side-Pumped Tm:YAG Laser with Output 51W

A compact diode-side-pumped Tm：YAG laser is presented, which can output 51 W of cw power at 2.02 μm. The Tm：YAG rod is side pumped by nine diode arrays with the central wavelength of 783nm and the with bandwidth of about 2.5 nm at 25^o C. To decrease the thermal effect on the both ends and dissipate the heat effectively, one composite Tm：YAG rod with the undoped YAG end caps and the screw threads on the side surface of the rod is used as the laser crystal. The maximum optical-to-optical conversion efficiency of the 2.02-μm laser output is 14.2%, with a slope effciency of 26.8%     

High peak power laser-diode-pumped passively Q-switched Nd:YVO4/Cr4+:YAG laser

In this paper, we report a high peak power passively Q-switched laser-diode-end-pumped Nd:YVO4/Cr4+:YAG laser polarized along the C axis, generating 4.23-W average power and 18-kW peak power (144-μJ pulse power) with 8.0-ns time duration (29.4-kHz repetition rate) at 1064 nm while the pump power is 21.2 W.