Simulating Transmission Characteristics of Phase-Shifted Fiber Bragg Gratings (FBG)

This document focuses on simulating the transmission characteristics of phase-shifted fiber Bragg gratings (FBG), including multiple phase-shift gratings. FBGs are essential optical fiber components used for selectively reflecting light signals at specific wavelengths. Transmission characteristics represent one of the key performance indicators for FBGs. Phase-shifted FBGs constitute a special category of FBGs whose transmission properties can be investigated through simulation. Multiple phase-shift gratings represent a variant of phase-shifted gratings that can enhance FBG bandwidth and flexibility, making them highly promising for optical communication and sensing applications. The simulation typically involves implementing the transfer matrix method or solving coupled-mode equations to model light propagation through the grating structure. Key parameters include grating period, phase-shift location, refractive index modulation, and number of phase shifts. This document will provide detailed analysis of multiple phase-shift grating transmission characteristics and their simulation methodologies, including code implementation approaches for calculating transmission spectra and phase responses, to better understand FBG performance and applications.