基于体布拉格光栅的Nd:YAG/Cr^(4+):YAG激光器波长调谐特性

Wavelength Tuning Characteristics of Nd:YAG/Cr^(4+):YAG Laser Based on Volume Bragg Grating

通过建立包含体布拉格光栅波长特性的速率方程模型,模拟了不同泵浦功率、体布拉格光栅中心衍射效率和带宽情况下,激光器的波长调谐特性,包括波长调谐范围、激光光谱、能量和脉冲宽度。实验搭建了以体布拉格光栅作为输出镜的激光二极管泵浦Nd:YAG/Cr^(4+):YAG激光器,测试了不同体布拉格光栅温度和泵浦功率时的激光波长、线宽、能量和脉冲宽度,实验结果和理论分析结果基本相符。在重复频率为10 kHz,脉冲宽度为40μs,峰值功率为10.7 W的矩形脉冲泵浦下,通过调整中心衍射效率为70%,带宽为60 pm的体布拉格光栅温度,获得了1 063.77~1 064.48 nm的波长调谐。当体布拉格光栅为50℃时,获得了单脉冲能量为109.5μJ,脉冲宽度为1.71 ns,中心波长为1 064.432 nm,线宽为38.3 pm,光束质量M~2因子小于1.2的激光输出。研究结果可为体布拉格光栅的应用、激光器的光谱分析及设计提供参考。

In theory,the tuning characteristics including tunable range,spectrum,energy and pulse width were simulated under different pump power,volume Bragg grating central diffraction efficiencies and spectral widths by setting up a rating equation model including volume Bragg grating wavelength property.A laser diode pumped Nd:YAG/Cr^(4+):YAG laser with a volume Bragg grating as output coupler was set up.The laser wavelength,linewidth,energy and pulse width were measured at different volume Bragg grating temperatures and pump power.The experimental results and theoretical results are in agreement.At the repetition rate of 10 kHz,pump pulse width of 40μs,pump peak power of 10.7 W,tunable range from 1063.77 to 1064.48 nm is obtained.When the volume Bragg grating temperature is 50℃,output energy of 109.5μJ,pulse width of 1.71 ns,wavelength of 1064.432 nm,linewidth of 38.3 pm,M2 factor of less than 1.2 is achieved.The investigating results can be a reference of volume Bragg grating application,spectral analysis and design of laser.