LiNbO3：Cr：Cu晶体吸收特性及非挥发全息存储研究

研究了LiNbO3：Cr：Cu晶体的吸收特性，发现LiNbO3：Cr：Cu（含0．14wt．％Cr2O3和0．011wt．％CuO）晶体存在两个明显的吸收峰，中心波长分别位于480nm和660nm；随着Cr的含量逐渐减小，Cu的含量逐渐增大，短波段不存在明显吸收峰，掺Cr的含量越大，中心波长在660nm处的吸收越大；633nm红光虽然位于中心波长为660nm的吸收峰内，但它无助于光折变过程．分别采用390nm紫外光和488nm蓝光作为敏化光，514nm绿光作为记录光的记录方案，实现了非挥发全息记录，掺入适

Ultrafast double pulses ablation of Cr film on glass

Ultrafast lasers ablation of Cr film was investigated by using double-pulse method. Experimental results show that there exists a temporal ablation window effect with each of the double pulses adjusted just smaller than the threshold. When the delay between the double pulses is within the order of 400 ps, the ablation of Cr film could happen. When the delay between the double pulses is beyond the order of 400 ps, the ablation of Cr film would not happen, and the reflectivity from the surface of the Cr film shows a sharp rise at the same time. The two-temperature model was developed into the form of double pulses to explain the experimental phenomena. Furthermore, microbump structures were formed on the surface of Cr film after ablation by ultrafast double pulses. Their heights exhibit an obvious drop between 1 and 10 ps double pulses delay, which is involved with the electron-phonon coupling process according to the numerical simulation. These results should be helpful for understanding the dynamic processes during ultrafast lasers ablation of metal films. (C) 2008 Elsevier B.V. All rights reserved.

Laser diode array side-pumped acousto-optic induced unidirectional operation Q-switched Nd : YAG slab ring laser

A laser-diode array (LDA) side-pumped Nd:YAG slab ring laser is described that incorporates a prism-shaped acousto-optic modulator to enforce unidirectional operation and Q-switching. When pumped by the maximum power of 50 W, Q-switched energies of 3.6 mJ and 50 ns duration, corresponding to a peak power of 72 kW, are obtained. (C) 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99)01306-9].

钕玻璃、Nd：YAG和Nd：GGG热容激光特性比较

考虑固体热容激光器对工作介质的要求，对比分析了掺钕的玻璃、YAG和GGG的多种材料性能。并对三者在激光工作周期内的瞬态温度场及热应力进行了数值模拟。结果表明：在给定的边界及工作条件下，当钕玻璃激光器以热容方式工作，时间为5S时，介质最高升温超过400K，最大热致应力为25MPa，接近其断裂极限的50％。在此条件下进行冷却，当水温为283K时，需经过约120S才基本恢复到初始工作状态。而Nd：YAG和Nd：GGG两种介质在相同输入工作条件下，工作时间可达10S，且温度分布相对平坦，温差和热应力较小，经水冷约

Cr~(2+):ZnSe的激光输出和调谐性能

Cr~(2+):ZnSe具有很宽的吸收带和发射带,是中红外波段优秀的可调谐激光材料。从吸收光谱、发射光谱以及角度调谐输出对Cr~(2+):ZnSe晶体的激光输出性能进行了研究。采用真空高温扩散法制备Cr~(2+):ZnSe晶体.获得了高浓度的Cr~(2+)离子掺杂的厚1.7 mm,直径10 mm的薄片ZnSe晶体。使用中心波长2.05μm,最大输出功率8 W的Tm离子掺杂的光纤激光器抽运,使用平凹腔结构搭建谐振腔,获得了最大平均功率1.034 W,中心波长2.367μm,线宽10 nm的连续激光输出。利用角度调谐的方法,对Cr:ZnSe晶体的调谐性能进行了研究,在100 nm范围内获得了调谐输出。