基于延时自外差法的窄线宽激光谱宽测量

Measurement of the Narrow Line Width Laser Spectrum Based on the Delayed Self-heterodyne

详细介绍了延时自外差法测激光线宽的理论模型与测量原理,得到了光电流的功率谱密度函数,并进行了软件仿真,分析并讨论了延时光纤长短对测量结果的影响,提出了在延时光纤长度不足条件下求解超窄激光线宽数值解的新方法,并在特定条件下给出了解析解,实验结果证明了算法的正确性。给出了在光纤长度300m时,对10kHz以下以及10kHz以上激光谱宽的不同求解方法并通过实验进行了验证。

Theoretical analysis and working principle of the delay self-heterodyne method for measuring laser line width are presented in detail.Based on the deduced power spectral density function,different lengths of fiber delay line are simulated and the influence on measuring results is analyzed.A new method is proposed to solve the arithmetic solution of the ultranarrow laser line width when the fiber delay line is too long for practical application.After that,a typical analytical solution under certain conditions is given.When laser length is 300 m,the different methods to solve laser spectrum are given and proved by experiment.