基于迈克耳孙干涉仪的共线自相关超短光脉冲测量

Collinear Autocorrelation Measurement of Ultrashort Laser Pulse Based on Michelson Interferometer

基于迈克耳孙干涉仪的原理,采用共线自相关的测量方法,同时对强度自相关和二维电场自相关进行测量。对强度自相关的测量数据进行高斯拟合,得到所测脉冲时域内光强的半峰全宽约为96.2fs;由CMOS图像传感芯片所测得的二维电场自相关中干涉条纹的分布情况,可以得到脉冲光斑波前相位的倾斜信息;通过对干涉条纹随时间延迟变化的漂移以及持续时间,采用傅里叶级数拟合分析手段,在延迟位移平台精度限制内,得到脉冲光功率谱存在微弱的1090nm成分。

The collinear autocorrelation measurement method is adopted based on the principle of Michelson interferometer, in which the intensity autocorrelation and the two-dimensional electric field autocorrelation are simultaneously measured. A Gaussian function is used to fit the intensity autocorrelation data and the full width at half maximum of the measured laser pulse in time domain is about 96.2 fs. From the interference fringe distribution of two-dimensional electric field autocorrelation obtained by the CMOS imaging sensor, the tilt information of pulsed light spot wavefront phase can be obtained. Moreover, the Fourier series analysis tool is adopted to fit the interference fringes shifting with time delay. Within the restriction of delay stage accuracy, a weak component at 1090 nm is disclosed in the pulsed laser power spectrum.