短脉冲在色散平坦光纤中传输前后波形、相位和啁啾测量的实验研究

二次谐波频率分辨光学门(SHG-FROG)是能够准确测量短脉冲多项特性参量的新技术。利用二次谐波频率分辨光学门脉冲分析仪对在色散平坦光纤中传输前后的短脉冲进行了测量,得到了待测光脉冲的频率分辨光学门(FROG)图、自相关曲线、自相关频谱曲线、波形和相位曲线以及脉宽、谱宽、啁啾等反映短脉冲特性的信息,对实验结果进行了分析,并与高斯脉冲在单模光纤中的线性传输理论进行了比较。结果表明,激光器输出的短脉冲是具有负线性啁啾的近变换极限高斯脉冲,经过12.7 km色散平坦光纤传输后仍然为具有负线性啁啾的高斯脉冲,其谱宽在传输过程中基本保持不变,脉宽展宽了3.1倍,啁啾增大了4倍。实验测量结果和理论预期一致。

Experimental Research on the Characteristic Measurement of the Short Pulses before and after Propagating in Dispersion-Flattened Fiber

The second-harmonic generation frequency-resolved optical gating(SHG-FROG) is a new measurement technique of short optical pulses developed in recent years.It can be used to exactly measure more characteristic parameters of the pulses than the other measurement techniques.Recently,the experimental research on the characteristic measurement of the short pulses before and after propagating in dispersion-flattened fiber(DFF) is completed by use of SHG-FROG analyzer,obtained the FROG trace,autocorrelation curve,autocorrelation spectral curve,waveform and phase curve,temporal width,spectral width,chirp and other parameters,compared with the propagation theory of Gauss pulse in a single-mode fiber.The results show that the measured parameters are consistent with the predictions of the theory.The pulses from the laser are near transform-limited Gauss pulses with negative linear chirp.After the pulses propagate over 12.7 km of DFF,the spectral width is almost unchanged,the temporal width is about three times as wide as that of input pulse,the chirp is about four times as large as that of input pulses.FROG technology is an effective means of measuring short optical pulses.