CLBO晶体和频产生深紫外激光的理论计算与实验结果

Theoretical Calculation and Experimental Result of Deep-ultraviolet Laser Generated by Sum-frequency Generation in CLBO Crystal

本文介绍了深紫外非线性光学晶体CLBO的光学特性,推导出了CLBO晶体和频时的相位匹配角、有效非线性系数、走离角、允许角宽度和允许温度范围的公式,并进行了详细计算。根据计算结果可知,CLBO晶体和频可以实现深紫外激光的有效输出,并且具有大的有效非线性系数、小的走离角、大的允许角宽度和允许温度范围。由此设计了1064nm近红外激光和238.7nm紫外激光通过CLBO晶体和频产生195nm深紫外激光的系统方案,并在实验中实现了平均功率217μW、重复频率10Hz的195nm激光的稳定运转。

The optical properties of deep-ultraviolet nonlinear optical crystal CLBO were introduced.Formulae of phase-matching angle,efficient nonlinear coefficient,walk-off angle,and acceptance angle and temperature range were derived and relevant data were calculated in detail.According to these data,it is proved that deep-ultraviolet laser can be generated by sum-frequency generation in CLBO with large efficient nonlinear coefficient,small walk-off angle,and large acceptance angle and temperature range.A scheme of sum-frequency generation by mixing 1064 nm near-infrared laser and 238.7 nm ultraviolet laser in a CLBO crystal was designed,and steady operation at 195 nm was achieved with 217 μW average power at 10 Hz in experiment.