We theoretically analyze the nonlinear phase shifts induced by cascaded χ<sup>(2)</sup>:χ<sup>(2)</sup> processes in one-dimensional photonic bandgap structures. We find that the enhancement of the density of modes near the band edge, coupled with a suitable choice of relative phase mismatch, leads to a remarkable new effect: The relative phase shift of the fundamental field on transmission can be of the order of π over a distance of 7μm , with input intensities of the order of only 10 MW/cm<sup>2</sup>.
© 1999 Optical Society of America
(050.5080) Diffraction and gratings : Phase shift
(060.5060) Fiber optics and optical communications : Phase modulation
(070.4340) Fourier optics and signal processing : Nonlinear optical signal processing
(190.0190) Nonlinear optics : Nonlinear optics
G. D'Aguanno, M. Centini, C. Sibilia, M. Bertolotti, M. Scalora, M. J. Bloemer, and C. M. Bowden, "Enhancement of χ(2) cascading processes in one-dimensional photonic bandgap structures," Opt. Lett. 24, 1663-1665 (1999)