Optical frequency combs currently represent enabling components in a wide number of fast-growing research fields, from frequency metrology to precision spectroscopy, from synchronization of telecommunication systems to environmental and biomedical spectrometry. As recently demonstrated, quadratic nonlinear media are a promising platform for optical frequency combs generation, through the onset of an internally pumped optical parametric oscillator in cavity enhanced second-harmonic generation systems. We present here a proposal for quadratic frequency comb generation in AlGaAs waveguide resonators. Based on the crystal symmetry properties of the AlGaAs material, quasi-phase matching can be realized in curved geometries (directional quasi-phase matching), thus ensuring efficient optical frequency conversion. We propose a novel design of AlGaAs waveguide resonators with strongly reduced total losses, compatible with long-path, high-quality resonators. By means of a numerical study, we predict efficient frequency comb generation with threshold powers in the microwatt range, paving the way for the full integration of frequency comb synthesizers in photonic circuits.

Date Published: 27 January 2017
PDF: 9 pages
Proc. SPIE 10111, Quantum Sensing and Nano Electronics and Photonics XIV, 1011120 (27 January 2017); doi: 10.1117/12.2256290

Published in SPIE Proceedings Vol. 10111:
Quantum Sensing and Nano Electronics and Photonics XIV
Manijeh Razeghi, Editor(s)