环形腔2.05μm单谐振KTP晶体光参量振荡器研究

Investigation on Ring-Cavity 2.05μm Single Resonant KTP Crystal Optical Parametric Oscillator

针对大气CO_2浓度探测差分吸收激光雷达的应用需求,采用稳定环形腔和模式匹配设计,搭建了一套单纵模1 064nm激光泵浦的单谐振KTP晶体光参量振荡器,获得高斜率转换效率、基横模的2.05μm波长纳秒激光脉冲输出.在8字形环形行波稳定腔中,将2块II类相位匹配KTP晶体以走离补偿方式放置,在20Hz重复频率下,当泵浦单脉冲能量达到11mJ时,获得了单脉冲能量为2.4mJ的2.05μm信号光输出,脉宽约24ns,斜率效率达到53%.2.05μm信号光光束质量因子在x、y方向分别为1.3和1.2.

Based on the application requirements of differential absorption lidar for atmospheric CO2 concentration detection,a single-resonant KTP crystal optical parametric oscillator,pumped by a 1 064 nm single-longitudinal-mode laser,was built with stable ring-cavity and mode matching design,and nanosecond laser pulse output at 2.05μm wavelength was achieved with high slope conversion efficiency.In the stable ring cavity with a bow-tie configuration,two KTP crystals with type II phase-match condition cut were placed in walk-off-compensated arrangement.When the pump pulse energy reached 11 mJ at a repetition rate of 20 Hz,2.4mJ of laser pulse energy output at 2.05μm signal wavelength was obtained with pulse width of around 24 ns,and the corresponding slope efficiency was 53%.The 2.05μm signal laser beam quality factor in xand ydirections were 1.3 and 1.2respectively.