Narrow-Linewidth Compound Ring Fiber Laser Using HBF as a Feedback for Sensing and Communication Application

Abstract

AbstractNarrow-linewidth compound ring fiber laser using high birefringence fiber(HBF) as feedback is newly proposed to generate highly stable narrowband fiber laser and enhance the free spectral range. The laser is basically structured on a Compound ring resonator with end reflector by inserting a piece gain mediam EDF in the main cavity, it has two rings: a primary ring that serves as a resonator, and a secondary ring that serves as a filter. When an Er3+-doped fiber is properly pumped, linear polarizer is located at the input port, effective free spectral range (FSR) of the reflected linearly polarized light is dramatically enhanced in compound ring setup due to the vernier effect between the traveling orthogonally polarized lights along the fast and slow axes of the HBF as well as between the primary and secondary rings. What’s more, it alleviates the cavity-length problem. To sum up, these special properties Compound ring resonator with high birefringence fiber in one arm is used in our configuration. Theoretical and simulation results are presented. The optimum design relationships are obtained.KeywordsCompound ring resonator with end reflector (CRRER)High birefringence fiber (HBF)Vernier effectFree spectral range (FSR)and Linewidth