Abstract

Second harmonic generation in a centrosymmetric photonic crystal, was recently demonstrated in an ordered suspension of dielectric microspheres of optical dimensions, coated with a nonlinear dye molecule.¹ Later, it was shown, using a theoretical analysis based on Rayleigh- Debye scattering, that the non vanishing field observed, is a result of the coherent addition of the scattered field from each portion of the sphere surface.² In the second harmonic generation process considered in references 1 and 2, the phase matching mechanism is provided by the bending of the photon dispersion curve at the edge of the Bragg reflection band for a given set of lattice planes. Maximum second harmonic light is obtained when the wavelength of the second harmonic field is generated at the high frequency edge of the Bragg stop band of the corresponding set of lattice planes.

© 1996 IEEE