腔内有双折射滤光片的激光实际线宽

在研制高效宽带增益激光非线性频率转化的实验中发现,由双折射滤光片透过率计算出的激光输出频谱宽度比激光器实际频谱宽度要大一个数量级左右.考虑到激光模式竞争和均匀增宽效应,理论上提出了一个精确计算激光器实际频谱线宽的模型.用该模型模拟的带不同厚度双折射滤光片的调Q运转钛宝石激光器的光谱宽度与实验结果一致,这为优化设计双折射滤光片及该类激光器提供了依据.

The Actual Linewidth of Laser with Birefringence Filter in Oscillator

It is efficient way to improve the efficiency of the nonlinear frequency conversion by birefringent filter to narrow the operation linewidth of fundamental laser. But an order of departure of bandwidth of laser with birefringent filter from that of single-pass transmission of birefringent filter is observed in experiment. Considering gain saturation and homogeneous broadening effects in the laser gain medium, a precision way to calculate the linewidth of laser with birefringent filter is developed. And a good agreement between theory and the output performance of a test Ti∶sapphire laser has been demonstrated. In experiment, the linewidth of Q-switch and femtosecond chirped pulse regenerative amplifier of Ti∶sapphire are investigated with different thickness birefringent filter.