Linewidth narrowing and polarization control of erbium-doped fiber laser by self-injection locking

摘要

A novel and simple self-injection locking (SIL) configuration of distributed feedback (DFB) fiber laser is presented. By injecting the feedback light into the cavity of the fiber laser, it can realize that the linewidth can be narrowed by half compared with the same system without SIL. Meanwhile the stable singlepolarization lasing is achieved and the degree of polarization is improved from 0.165 to 0.989. Then the selfpulsation behavior of the DFB fiber laser is investigated in the injection-locked and unlocked system respectively and the output power fluctuation is reduced from about 4 to 0.1 dBm by injection locking. And the power output characteristics of the DFB fiber laser are also researched by changing the pump current. With increasing the pump current from 30 to 275 mA, the output power of the DFB fiber laser increases linearly and the injection-locked output increases slightly more quickly than the unlocked output. The results have a great potential application in optical communication and high sensitive fiber sensors.