Optimization of refractive index sampling for multichannel fiber Bragg gratings

A comprehensive analysis of multichannel grating optimization strategies is presented. The central idea is in dephasing of partial gratings with respect to each other. This dephasing allows the utilization of ultraviolet-induced refractive index changes with maximum efficiency. The dependence of group delay ripple on optimization strategy, number of channels, and other grating characteristics is also briefly discussed. Finally, we discuss further generalization of the dephasing approach to the case of multichannel gratings with nonidentical spectral characteristics.