目前,在被动锁模掺铒光纤激光器中,进行腔内色散补偿的方法主要包括:在激光谐振腔内熔接一段具有正常色散的光子晶体光纤、插入具有正常色散的光栅对，以及利用具有正常色散的啁啾光纤光栅等。针对目前腔内色散补偿方法存在的耦合效率低、环境稳定性差、色散量不易调节等不足，设计了一种由偏振合束器、色散补偿光纤和法拉第旋转镜构成的线形支路进行腔内色散精确补偿,采用透射式可饱和吸收体实现自启动锁模,并结合混合光器件,实验获得了重复频率为82.84 MHz、平均功率为10 mW、脉冲宽度为381 fs的飞秒脉冲保偏输出,作为种子源,可广泛应用于太赫兹产生、生物医学成像、超快光谱学等领域。

At present, the methods of intra cavity dispersion compensation in passive mode-locked erbium-doped fiber lasers mainly include: fusing a photonic crystal fiber with normal dispersion in the laser cavity, inserting the grating pairs with normal dispersion and using the normal chromatic dispersion chirped fiber gratings. Aiming at the shortcomings of current intra cavity dispersion compensation methods, such as low coupling efficiency, poor environmental stability and hard to adjust dispersion, a linear branch composed of polarization beam splitter, dispersion compensation fiber and Faraday rotating mirror is designed to compensate cavity dispersion precisely. In this experiment, femtosecond pulses with repetition rate of 82.84 MHz, average power of 10 mW and pulse width of 381 fs have been obtained by using a transmissive saturable absorber to achieve self-starting mode-locking, and using the hybrid optical device. As seed source, it can be widely used in terahertz generation, biomedical imaging, ultrafast spectroscopy and other fields.