Modeling and fabrication of chirped moiré fiber grating

The chirped moiré fiber grating (CMFG) is numerically analyzed by taking in count of the factors of the initial exposure phase, the refractive index modulation strength and the grating period difference. And several CMFGs with different amounts of transmission peaks are fabricated by dual-exposure with a single chirped phase mask. The CMFG possesses excellent comb-like filtering characteristics including stable wavelength interval and ultra-narrow pass-bands, so it is suitable to serve as wavelength selective element. Moreover, its fabrication method is easy and flexible.