Research on Equivalent Phase-shifted Fiber Bragg Grating's Reflection Spectrum Characteristics

The principle of equal-phase shifted fiber Bragg grating is that by introducing a spatial shift at cer-tain position of sampling fiber Bragg grating, equivalent phase shift can be achieved in different frequency channelafter Fourier transformation. Firstly, the fiber Bragg grating Turan transmission matrix is used to perform numbersimulation, and all kinds of phase shifted fiber Bragg grating's properties are verified in equal-phase shifted fiberBragg grating. Secondly, according to the report that-2 grade fiber Bragg grating has low reflectivity and equalphase shifted state can't be realized, a method for realizing-2 grade equal-phase shifting is proposed and relativeverification is performed. Finally, the relationship curve of equal- phase shifted fiber Bragg grating reflectivitychanging with length is given.