Novel multi-channel fiber-optic filters based on step-chirped sampled Bragg grating

► In this study we model a kind of fiber filter. ► The filter is based on a strongly discretely chirped sampled Bragg grating. ► Fabrication of corresponding phase mask is easy and cheap by e-beam lithography. ► The channel performance of high transmittance, flat-top and steep edge is obtained. ► A small variance of group delay in the passbands leads to a small dispersion.