通过1 064 nm激光泵浦KTP晶体光参量振荡(OPO)技术获得了高峰值功率2.7 μm波段激光输出, 对实验结果开展了详细的分析。泵浦源为电光调Q Nd:YAG激光器, 光参量振荡器谐振腔采用单谐振结构, 将两块相同的KTP晶体光轴相向放置以补偿走离效应, KTP晶体按?=0°, θ=62°切割以获得波长2.7 μm波段激光输出, 采用Ⅱ(B)类相位匹配(o→o+e)以利用较大的非线性系数。在泵浦能量为89 mJ, 脉宽10 ns的条件下, 获得脉冲能量7.5 mJ, 波长2.67 μm, 脉宽8.5 ns的激光输出。

The output of 2.7 μm wave band laser with high peak power is obtained by KTiOPO4 (KTP) crystal optical parametric oscillation (OPO) pumped by 1 064 nm laser. Experimental results are analyzed in detail. The pump source is an electro-optical Q switched Nd:YAG laser, and the OPO is singly resonated. Two identical KTP crystals are placed with opposite optical axis to compensate the walk off effect. The crystals are cut as ?=0°, θ=62° to generate 2.7 μm wave band laser. To utilize the larger effective nonlinear coefficient, the phase matching is based on type Ⅱ(B) (o→o+e). When the pump energy of the 1 064 nm laser is 89 mJ with a pulse width of 10 ns, an output energy of 7.5 mJ with a pulse width of 8.5 ns at 2.67 μm is obtained.