计算啁啾，均匀，取样光栅透射谱。可以改变周期，占空比，长度等各种参数-Calculated chirp, evenly sampled grating transmission spectrum. Can change the various parameters of the period, duty cycle, length, etc.

用于matlab仿真任意切趾的均匀光栅或者切趾光栅，主程序stepchirp.m(Numerically simulation for chirp or uniform fiber Bragg grating by Matlab. Main proceedings: stepchirp.m)