AHigh birefringence coherent fiber filter with selectable wavelengths

Filter is an indispensable component for optical fiber communication system, especially for filter with all-fiber structure and selectable wavelength spacing due to its unique characteristics. A novel periodic filter with interleaving wavelengths based on high birefringence fiber interferometer was proposed and theoretically analyzed. Simulation results indicate that this filter has unique features. By adjusting the combination of the polarization rotations in this comb filter, filtering channels can be chosen by suppressing interleaving channels. The efficiency of the birefringence fiber is enhanced, as using 12m high-birefringence fiber can obtain the same filtering results with using 16m birefringence fiber in the Sagnac filter. This filter has potential applications for multi-wavelength fiber laser and other optical fiber communication system.