Analysis and Applications of Phase Shifts for Multichannel Fiber Bragg Grating

摘要

A novel phase compensation method to improve comb filters performance by increasing DC refractive index of linearly chirped fiber Bragg grating (LCFBG) is proposed. Nonlinear chirp introduced by linearly chirped mask is discussed, and then DC phase shift compensate method is proposed. Two kinds of DC phase shift LCFBGs are analyzed, which shows a good agreement with traditional discrete phase shift method. A DC phase shift comb filter is realized with the help of a micrometer-precision translation stage, which shows the feasibility to introduce DC phase shift in LCFBG. A high flattened comb filter with precise 0.8 nm channel spacing is realized with the help of a micrometer precision translation stage.