腔内倍频激光器中损耗对输出噪声的影响

在多纵模工作状态下,腔内倍频激光器往往存在很大的倍频光输出功率噪声.通过对描述倍频激光器噪声行为的耦合微分方程组的数值模拟,发现在腔内基频光两个或者三个纵模起振的情况下,腔内基频光的损耗对于激光倍频输出的噪声存在很重要的影响.该情况下,如果基频光受到较大损耗,倍频光抖动周期变小,尖峰个数明显增多,将极大地增加倍频光功率的抖动.通过对倍频光输出功率的频谱FFT分析发现,当腔内基频光经受的损耗增大时,倍频输出功率在很大的频段范围内都存在噪声分布,输出功率的频谱FFT分布包络上面叠加的尖峰变多变密,激光器的噪声变大并趋于高频化.

The Influence of Losses to Noise of Output Power in Intracavity-frequency-doubled Laser

When a doubled crystal is placed within a multimode solid-state laser cavity,large amplitude fluctuations(the noise of the intracavity-frequency-doubled solid-state lasers) are observed.Through numerical simulation of coupled differential equations which describe the noise dynamics of the intracavity-frequency-doubled laser found that the losses of fundamental longitudinal modes effect the properties of noise when two or three fundamental-frequency longitudinal modes are operated..The periods of power fluctuations of intracavity-frequency-doubled laser are decreased and the numbers of peaks are increased if the losses are larger.Through FFT translation of power fluctuations of frequency-doubled laser,the noise will distribute at larger frequency regions and the frequency-spectrum of noise will remove to high-frequency regions.