LaAlO_3/SrTiO_3界面增强光伏效应

探索LaAlO_3/SrTiO_3(LAO/STO)界面产生的新奇物理特性对理解关联电子系统中多自由度耦合和设计功能材料器件具有重要的价值.本文通过脉冲激光沉积方法在SrTiO_3基底上制备了LAO/STO薄膜,研究了正面照射LAO/STO膜面和侧面照射LAO/STO界面时的光伏效应,探讨了LAO/STO界面对光伏效应的影响.研究结果表明,在同样光照能量下侧面照射LAO/STO界面产生的光电压远高于正面照射LAO/STO膜面产生的光电压,说明LAO/STO界面对光伏效应有明显的增强作用.通过偏压调控可以进一步增强照射LAO/STO界面产生的光电压,当偏压为60 V时, LAO/STO样品的位置探测灵敏度达到了36.8 mV/mm.这些研究结果为设计场调控位置敏感探测器等新型光电子器件提供了新的思路.     

High Beam Quality Green Generation with Output 140W Based on a Thermally-Near-Unstable Flat-Flat Resonator

By using a diode-side-pumped Q-switched Nd:YAG rod laser based on a thermally-near-unstable fiat-fiat resonator, an intracavity-frequency-doubled green beam generation is investigated. Output power 140 W is obtained at a repetition rate of 10kHz and a pulse width of 110ns. The green beam quality factors Mx^2 and My^2, which are measured by a laser beam analyser, are 10.65 and 10.85, respectively, at output power of 124W.     

Highly efficient diode-pumped seven-rod resonator with a 3.79-kW output

Thermally stable region of a seven-rod resonator is theoretically investigated. A plane-plane symmetric resonator, where the distance between two neighbor rods is two times of that between the rods and the mirrors, is adopted because of its large stable range. Based on the investigation, a seven-rod resonator with an average output power of 3.79 kW and an optical-to-optical efficiency of 53% is developed.     

高效率激光二极管泵浦100 Hz 3.5 J Nd∶YAG MOPA激光器

研制了结构简单、高效率激光二极管泵浦Nd∶YAGM0PA激光器.振荡级输出单脉冲能量1.13 J,重复频率为100HZ.MOPA系统输出最大单脉冲能量2.35 J,光-光转换效率为39%.实验结果和理论计算符合较好.     

Generation of 2.1 W Continuous Wave Blue Light by Intracavity Doubling of a Diode-End-Pumped Nd：YAG Laser in a 30 mm LBO

A folded four-mirror cavity with a composite Nd：YAG rod is optimized to obtain high efficient cw 473nm blue output. The laser could operate stably in the region of the thermal-lens focal length from 20mm to 70mm. LBO is used for intracavity frequency doubling of the 946nm transition of Nd：YAG and the optimum LBO length is investigated. A maximum output power of 2.1 Win the blue spectral range at 473nm is achieved with 30-mm-long LBO, corresponding to an optical conversion efficiency of 9.1%.     

应用干涉原理检测激光晶体夹具的应力

详细介绍了激光干涉原理,在此基础上,引入了一种简单实用的板条激光器夹具应力检测方法,从而减小了应力对板条激光器带来的不利影响。实验结果表明：夹具对板条各个方向产生的应力均匀,通过初步实验得到了6.94 W的1 064 nm连续光输出。     

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).     

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.     

高效率激光二极管泵浦100 Hz 3.5 J Nd：YAG MOPA激光器

研制了结构简单、高效率激光二极管泵浦Nd:YAG MOPA激光器.振荡级输出单脉冲能量1.13J,重复频率为100 HZ.MOPA系统输出最大单脉冲能量2.35 J,光-光转换效率为39％.实验结果和理论计算符合较好.     

1.15 kW连续波全固态Nd:YAG激光器

研制了五组双线二极管列阵侧面泵浦Nd: YAG棒的高效率、高功率激光头。将一块90° 石英旋光片插入两个这样的激光头中间并置入热近非稳对称平平腔，产生了1157 W高光束质量（M2 ~ 39）1064 nm连续波输出，据我们所知，这是侧面泵浦双棒Nd: YAG激光器产生的最高功率。