Single polarization output of erbium-doped DFB fiber laser by self-injection locking

A simple self-injection locking (SIL) configuration of DFB fiber laser is presented, which is composed of an optical circulator, a isolator and a polarization controller. By injecting the feedback laser into the DFB fiber laser, it can realize the stable single-polarization lasing with a degree of polarization larger than 0.98. And a high resolution phase-shift fiber grating transmission spectrum, output power, and optical spectrum characteristics of the laser are also measured. The results have potential application in optical communication and high sensitive fiber sensors.