Abstract

Photonic bandgap materials, often also called photonic crystals, are engineered materials with a periodicity in dielectric properties.¹ This periodicity results in a range of forbidden energies for a photon: Photons with the wavelength in the corresponding photonic bandgap cannot propagate through the material. Recently, second-harmonic generation has been realised in a photonic crystal.² In a nonlinear photonic crystal, the optical nonlinearity of the harmonic generating material (the hyperpolarisability) is decoupled from the linear optical properties (the refractive index). This has important consequences on phase-matching schemes for efficient nonlinear conversion in these materials.

© 2000 IEEE