Magnetization-induced second- and third-harmonic generation in magnetophotonic crystals

Abstract

The results of our recent studies of magnetization-induced nonlinear-optical second- and third-order effects in magnetophotonic crystals and magnetophotonic microcavities are surveyed. Magnetophotonic crystals (MPCs) are fabricated from a stack of four repetitions of lambda/4-thick layers of Bi-substituted yttrium iron garnet (Bi:YIG) and lambda/4-thick SiO2 layers. Magnetophotonic microcavities (MMCs) are formed from two dielectric (nonmagnetic) Bragg reflectors and ferromagnetic cavity spacers that are lambda/2-thick Bi:YIG layers. The nonlinear magneto-optical Kerr effect (NOMOKE), both in magnetization-induced second-harmonic generation (MSHG) and magnetization-induced third-harmonic generation (MTHG), is observed in MMCs at wavelengths of the resonant microcavity modes. Magnetization-induced variations of MSHG and MTHG intensities, as well as magnetization-induced shift of phase and rotation of polarization of second and third-harmonic waves, are observed in proper - transversal, longitudinal, or polar - NOMOKE configurations. Manyfold enhancement of the absolute values of both the MSHG and MTHG intensities are attributed to the localization of the resonant fundamental radiation in Bi:YIG microcavity spacers. The NOMOKE in MSHG intensity is observed in MPCs in the spectral range of photonic bandgap (PBG) edges. The MSHG intensity reveals enhancement by a factor of more than 10^2 if the fundamental wavelength is tuned in the vicinity of the PBG edge. This enhancement is attributed to the fulfillment of the phase-matching conditions for MSHG effect in layered structures with periodic modulation of both optical (magneto-optical) and nonlinear optical parameters.