基于改进的单次自相关测量飞秒激光脉冲的时空特性

摘要

To overcome the shortcomings of the single-shot autocorrelation SSA where only one pulse width is obtained when the SSA is applied to measure the pulse width of ultrashort laser pulses a modified SSA for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions is proposed. The spatiotemporal characteristics of femtosecond laser pulses output from the Ti sapphire regenerative amplifier system are experimentally measured by the proposed method. It was found that the complex spatial characteristics are measured accurately.The pulse widths at different spatial positions are various which obey the Gaussian distribution.The pulse width at the same spatial position becomes narrow with the increase in input average power when femtosecond laser pulses pass through a carbon disulfide CS2 nonlinear medium.The experimental results verify that the proposed method is valid for measuring the spatiotemporal characteristics of ultrashort laser pulses at different spatial positions.%针对单次自相关方法只能测量一个脉宽的缺点，提出一种改进的单次相关方法测量超短激光脉冲全空域中不同空间位置的时空特性。通过实验测量了钛宝石激光器输出飞秒激光脉冲的时空特性，结果表明飞秒激光脉冲全空域中不同位置的复杂空间特性得以精密测量；不同空间位置的时间脉宽不同，它们服从高斯分布；当飞秒激光脉冲经过二硫化碳非线性介质传输后，随着输入平均功率的增加，同一空间位置的时间脉宽呈现慢慢变窄的趋势。实验结果验证了所提方法可以有效地测量超短激光脉冲全空域中不同空间位置的时空特性。