频率分辨光学开关法测量飞秒脉冲

阐述了频率分辨光学开关法测量飞秒脉冲的原理，详细分析了模式尺寸效应和非线性效应对飞秒脉冲测量的影响。构建了一台用于飞秒脉冲测量的二次谐波-频率分辨光学开关装置，利用该装置对谐振腔输出的飞秒脉冲及压缩后的脉冲进行了测量。得到了飞秒脉冲的时间宽度及光谱宽度、电场及其相位在时域和频域的详细信息。谐振腔直接输出脉冲的时间宽度为56 fs，光谱宽度为27 nm，时间带宽积为0.686，算法中的最小误差为0.001792。脉冲压缩后的测量结果为27 fs，光谱宽度为92 nm，时间带宽积为1.27，算法误差为0.00

The basic concept underlying the frequency-resolved optical gating (FROG) pulse characterization technique is reviewed, and the influence of mode-size effect and nonlinear effect of second-harmonic generation medium on femtosecond pulse measurement are discussed in detail. A second harmonic FROG is set up to measure femtosecond laser pulses. The width, field and phase in temporal and spectral domains are retrieved. The temporal width of a femtosecond pulse coming from the resonant cavity directly is 56 fs, with spectral width 27 nm, time-bandwidth product 0.686, and the minimum error 0.001792. The femtosecond pulse is compressed by a prism pair, with pulse duration 27 fs, bandwidth 92 nm, time-bandwidth product 1.27, and the minimum error 0.0093289.