Optical fiber with distributed Bragg-type reflector

Optical fiber (OF) with a relatively high level of the backward signal at a certain wavelength is developed and studied. An increase in the backward signal is reached due to the recording of multiple weak fiber Bragg gratings (FBGs) in the course of fiber pulling. A scheme that is simpler than the direct FBG recording through a phase mask is proposed and implemented. Fibers with FBG recorded with different ratios of the region with recorded gratings to the total length of OF are fabricated. An increase in the level of the backward signal relative to the level of the Rayleigh scattering by more than 30 dB is reached. Results of experimental study of the proposed OFs and examples of practical application are presented.