用于赝热光鬼成像双波长高分辨激光光源研制

Development on High Resolution Dual Wavelength Passive Q-switched Laser System for Pseudo-thermal Light Source

报道了一种基于Cr^(4+):YAG晶体被动调Q的Nd:YAG行倍频后获得稳定的532 nm激光输出。该激光器输出1 064 nm大于500 mJ,在不同重频下的输出能量分别为551 mJ@1 Hz,553 mJ@3Hz,546 mJ@5 Hz和518 mJ@10 Hz,脉冲能量RMS<6.2%。光源入射到直径为20 cm的毛玻璃上,CCD采集图像经计算得到,该赝热光源的二阶量子相关函数g(2)为1.963,接近理论值2。该激光系统为赝热光鬼成像提供了良好的光源。

A compact Nd:YAG nanosecond laser passively Q-switched by Cr4+:YAG crystal with the operation repetition tunable from 1 Hz to 10 Hz is reported. Type Ⅱ phase match crystal of KTP is adopted for the frequency doubling to obtain the stable output of 532 nm laser pulse. The single laser pulse energy of 1 064 nm is approxi?mately 800 mJ and the laser pulse width is around 7 ns. The output energy of 532 nm exceeds 500 mJ, and the average pulse energy at different operation repetition are given as 551 mJ@1 Hz, 553 mJ@3 Hz, 546 mJ@5 Hz and 518 mJ@10 Hz, respectively. The RMS of 532 nm laser pulse energy is less than 6.2%. When the laser beam is injected onto a ground glass of 20 cm, the spot image is measured by a scientific-level CCD. The result shows that the second-order quantum correlation function g(2)value of the pseudo-thermal light is 1.963, close to the theoretical value of 2. The laser system promises the improvement of Ghost imaging quality.