飞秒激光脉冲的腔外压缩

为了获得更高的时间分辨率,更短的飞秒脉冲,采用双棱镜和一个平面镜结构对飞秒激光脉冲进行腔外压缩,构建了一台二次谐波频率分辨光学开关装置,对谐振腔输出的飞秒脉冲及压缩后的脉冲进行了测量,取得了脉冲压缩前和压缩后的实验数据,压缩前脉冲的宽度为89fs,脉冲的时间带宽积为0.9096,误差为2.4‰,输入脉冲的平均功率约为480mW;脉冲压缩后的测量结果为22fs,光谱宽度为43nm,时间带宽积为0.44203,误差为1.1‰,压缩脉冲的平均功率约为250mW.压缩比为4:1,高于有关文献的报道.结果表明,该装置实现了飞秒脉冲腔外压缩,对获得更短的飞秒脉冲是有帮助的.

Compressing femtosecond pulse in outer cavity

In order to get shorter pulse width to improve time resolution,femtosecond pulse was compressed by using two prisms and a reflective mirror. Femtosecond pulse was measured with a home-made second-harmonic generation frequencyresolved optical gating. The temporal width of input pulse was 89fs,the time-bandwidth product was 0.9096,the minimum error was 2.4‰ and the average power of the input light was about 480mW. The width of compressed pulse was 22fs,the timebandwidth product was 0.44203,the minimum error was 1.1 ‰ and the average power of the output light was about 250mW. The compression ratio was 4∶1,which was higher than that in the related report. The experimental results indicate that the compressing device is valid and the result is useful for getting shorter pulses.