论文部分内容阅读
提出了基于宽谱半导体激光器连续激光光腔衰荡法测量高反射率的方法,给出了方波调制连续激光光腔衰荡法理论。采用锁相技术记录光腔输出信号一次谐波的振幅和相位,由振幅和相位随调制频率的变化曲线分别拟合衰荡时间。给出了不同腔长下两种拟合方式分别得到的衰荡时间,最终确定腔镜反射率为99.70%,误差小于0.01%。由频域拟合方式得到反射率结果,使可靠性得到提高。与脉冲激光光腔衰荡法相比,采用连续半导体激光器作光源,大大降低了成本,且由于光束质量高,更有利于提高测量精度。
The method of measuring the high reflectivity based on continuous laser cavity ring-down method based on wide-spectrum semiconductor laser is proposed, and the theory of square-wave modulated CW laser cavity ring-down method is given. Phase-locked technique is used to record the amplitude and phase of the first harmonic of the output signal of the optical cavity, and the ring-down time is fitted by the curve of amplitude and phase with the modulation frequency. The ring-down time obtained by the two fitting methods with different cavity length is given, and the endoscopic reflectance is finally determined to be 99.70% and the error less than 0.01%. Reflectance results obtained by the frequency-domain fitting method, the reliability is improved. Compared with the pulse laser cavity ring-down method, the continuous semiconductor laser as the light source, greatly reducing the cost, and because of the high beam quality, more conducive to improving the measurement accuracy.