Based on the fact that dielectric film filter is minimum phase filter, this paper provided a method to reconstruct phase response from its amplitude response and then for the group velocity delay (GVD) and the chromatic dispersion.

The theoretical model of type-Ⅰ and type-Ⅱ phase matching conditions for second harmonic generation,group velocity delay of fundamental and second harmonic,and limitation of nonlinear crystal matching length by group velocity mismatch,was obtained by using energy conservation and three-wave coupled equations in optical parametric process of ultra-short pulses.

Realization of multichannel group delay based on thickness-tapered photonic crystals;

Study on signal group delay estimating methods

Photonic crystal superprism is the key device for the light deflection,filtering and so on,and the group delay is one of the most important parameters to judge light deflection and filtering performances.