针对混沌光相干性差以及偏振态随机起伏的问题,提出了一种基于高非线性光纤中的四波混频效应对混沌激光偏振不敏感的采样方案,并通过数值的方法对波长为1550nm,功率范围为0~10mw的混沌光进行了采样。经研究发现,当抽运光功率为2w,波长为1557nm,光纤长度取60m时,可使四波混频采样达到最佳。采用上述参数,数值实现了对混沌光的偏振不敏感采样,采样速率为5GHz,采样的同时也起到了光放大的作用,增益系数约为10.8dB。该结果可为实验上进一步实现混沌光的四波混频采样提供一定的理论依据。
Based on four-wave mixing in highly nonlinear fiber, a scheme to chaotic laser sampling independent of polarization is proposed due to poor coherence of chaotic laser, and random fluctuations of polarization state. And the chaotic laser with wavelength of 1550 nm and power range from 0-10 mW is sampled by numerical method. It can be found that the four-wave mixing sampling can be optimal for the pump light with wavelength of 1557 nm and power of 2 W when the fiber length is 60 m. Using the above parameters, polarization insensitive sampling for chaotic laser is implemented with sample rate of 5 GHz. The peak power of the chaotic pulse is amplified. The gain coefficient is approximately 10.8 dB. The results can provide a theoretical basis for the further experiment.