为了实现高转化率3μm红外激光光参量振荡输出，采用外加脉冲电场法在厚度为1mm、掺摩尔分数为0.05的镁铌酸锂晶体上成功制备了周期为31.2μm的极化光栅，理论计算并模拟了1064nm激光抽运周期极化铌酸锂晶体时，闲频光波长随温度的对应关系，并进行了实验验证。利用1064nm声光调Q Nd∶YAG激光器作为抽运源对样品进行了光学参量振荡实验，其中，脉冲激光脉宽为200ns，重复频率是20kHz。在控制温度为80℃、输入抽运光功率为5567W时，光参量振荡输出波长3μm的闲频光功率为1.141W，光光转换效率达到20.1%。结果表明，通过此方法制备的周期性极化铌酸锂晶体光参量振荡，具有较高的光光转换效率。

In order to achieve high conversion rate of 3μm infrared laser output from an optical parametric oscillation, by using the applied pulse electric field method, periodically poled grating of 31.2μm was prepared on MgO-doped(mole fraction of 0.05) lithium niobate crystal with the thickness of 1mm. The relationship between idler wavelength and temperature when periodically poled MgO-doped LiNbO3 pumped by 1064nm pulsed laser was studied by theoretical calculation and simulation. Acousto-optic Q-switched Nd∶YAG laser with the wavelength of 1064nm was used as the fundamental source to operate optical parametric oscillation experiment with pulse width of 200ns and repetition rate of 20kHz. When pulse input power is 5.567W at the temperature of 80℃, idler output power of 1.141W was obtained with output wavelength of 3μm. The maximum conversion efficiency from incident pump power to idler output was 20.1%. The results show that this method of preparation by periodically poled lithium niobate optical parametric oscillation has high optical conversion efficiency.