Free spectral range variation of broadband, high finesse, multi-channel Fabry-Perot filter with chirped fiber Bragg gratings

In conclusion, the free spectral range (FSR) variation of a Fabry Perot (FP) filter with linearly chirped fiber gratings was determined by the relationship between the separated distance of two fiber gratings and the total transmitted phase change. By modeling of an all-fiber interferometric FP filter with linearly chirped fiber gratings we will be able to increase the channel number of WDM systems for telecommunication and also provide a sophisticated tool as a multi-channel high resolution filter for sensor applications.