Dual wavelength evanescent coupler for nonlinear GaP-based microdisk resonators

Abstract

Wavelength conversion is one of the most demanded features in integrated photonics. During the last decade, second harmonic generation (SHG) in III-V semiconductor microdisks has been demonstrated to be an efficient way to achieve such conversion with particularly compact devices. Optimized coupling of both wavelengths to these devices still remains as a challenge. Here we compare three different approaches for vertical coupling between integrated waveguides and a III-V microdisk resonator in which SHG occurs: two well-established schemes and a new one using a single slit waveguide as an evanescent coupler.