重复频率连续可调谐的Cr4+:YAG被动调Q微片激光器

激光二极管泵浦的Cr4+:YAG被动调Q微片激光器因其高重复频率、短脉宽、高峰值功率等优点，在光通信、激光雷达、遥感监测、非线性频率变换、激光微加工等领域有着重要应用，然而目前Cr4+:YAG被动调Q激光器脉冲输出稳定性较差，而且重复频率调谐范围窄，限制了其在气溶胶的荧光分析、测距以及空间光通信等领域中的广泛应用。实验中采用预泵浦方式，在激光二极管泵浦的Cr4+:YAG被动调Q微片激光器中获得重复频率连续可调、稳定振荡的激光脉冲输出，重复频率连续可调谐范围为2 ~28 kHz，其单脉冲能量的不稳定性优于2.50%。其中，在重复频率为20 kHz时，获得脉冲宽度为2.431 ns，单脉冲能量17.6 J，消光比252:1的脉冲输出，其幅度不稳定度约为4.00%，重复频率不稳定度约为2.40%。此类宽频可调、稳定振荡的激光二极管泵浦的Cr4+:YAG被动调Q微片激光器有着广阔的应用前景。

Repetition rate continuously tunable microchip laser passively Q-switched by Cr4+:YAG

Laser diode pumped microchip lasers passively Q-switched by Cr4+:YAG, with high repetition rate, short pulse width and high peak power, have important applications in optical communication, lidar, remote sensing, nonlinear frequency conversion, laser micro-processing and so on. However, in these lasers, the output stability is poor and the repetition rate of output laser cannot be changed widely. This will restrict the applications of these lasers in fluorescence analysis of aerosols or ranging, space optical communication. In the experiment, output pulses with continuously tunable repetition rate from 2 kHz to 28 kHz and stable oscillation were obtained in the laser diode pumped microchip laser passively Q-switched by Cr4+:YAG. In the stability of single pulse energy from 2 kHz to 28 kHz was less than 2.50%. Stable 2.431 ns pulse at 20 kHz with single pulse energy of 17.6 J and extinction ratio of 252:1 and with amplitude instability of 4.00% and frequency instability of 2.40% was obtained. This laser diode pumped microchip laser passively Q-switched by Cr4+:YAG with wide continuously tunable repetition rate and stable oscillation will have broad application prospects.