Giant third-harmonic generation in porous silicon photonic crystals and microcavities

Summary form only given. The control of optical field localization and effective dispersion relations in optical microcavities (MC) fabricated from photonic band gap structures allows to enhance their nonlinear-optical response. Recently the giant enhancement of the second-harmonic generation (SHG) is experimentally observed in spectral vicinity of MC model and at the edges of photonic band gap. At MC mode the fundamental field is strongly localized in the vicinity of cavity layer leading to giant enhancement of nonlinear-optical response of MC. Thus the microcavity-induced enhancement of the nonlinear-optical effects depending on higher power of fundamental radiation such as third-harmonic generation is expected to be even larger than for SHG. In this paper we report the fabrication of the specially designed porous silicon MC with the cavity mode located inside the photonic band gap and the experimental observation of the enhancement of the third-harmonic response of such microstructures in the vicinity of the MC mode and at the edges of photonic band gap.