Linearization processing of a novel short time-delay WDM superposed fiber Bragg grating

A new analytical method for short time-delay profile linearization of wavelength division multiplexing superposed fiber Bragg grating is presented. This can obtain a new index profile for the gratings that results in a highly linear time-delay step profile. An optimum apodization using a cos/sup 4/ function is described for suppressing grating sidelobe interaction. Results demonstrate a highly linear time-delay step profile for a 32-superposed grating, with only a 1.7% standard deviation from linearity, 1-ps delay steps, and more than 99% reflectivity.