FREE SPECTRAL RANGE VARIATION OF A BROAD-BAND, HIGH-FINESSE, MULTICHANNEL FABRY-PEROT FILTER USING CHIRPED FIBER BRAGG GRATINGS

The free spectral range (FSR) variation of a broadband, high finesse, multi-channel Fabry-Perot (FP) filter using linearly chirped fiber gra tings has been studied theoretically. It is found that the FSR variati on of the FP filter using linearly chirped fiber gratings was determin ed by the relationship between the distance between two fiber gratings and the total transmitted phase change. The variation of the FSR of a FP filter using linearly chirped fiber gratings was explained by the equation obtained in this study. This simulation dealt with three type s of FP filters using linearly chirped fiber gratings of different gra ting lengths for 1.3 mu m single mode fibers. These were 4.47 mm, 6.67 mm and 7.50 mm in grating length, which are easily obtainable using r ecent inscription technologies. The different behaviors of the spectra l response of FP filters using fiber gratings and bulk FP etalon were also established.