Efficient second harmonic generation in low-loss planar GaN waveguides
Description | |
Date | |
Authors | Gromovyi M., Brault J., Courville A., Rennesson S., Semond F., Feuillet G., Baldi P., Boucaud P., Duboz J.-Y., De Micheli M.P. |
Year | 2017-0446 |
Source-Title | Optics Express |
Affiliations | Université Côte d’Azur, CNRS, CRHEA, rue Bernard Grégory, Valbonne, France, Université Côte d’Azur, CNRS, IN?NI, Parc Valrose, Nice, France, Centre de Nanosciences et de Nanotechnologies, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Bâtiment 220, Rue André Ampère, Orsay, France, Université Grenoble Alpes, CEA, LETI, MINATEC Campus, Grenoble, France |
Abstract | We demonstrate low-loss GaN/AlGaN planar waveguides grown by molecular beam epitaxy on sapphire substrates. By using a proper AlGaN cladding layer and reducing surface roughness we reach <,1dB/cm propagation losses at 633nm. These low propagation losses allow an efficient second harmonic generation using modal phase matching between a TM0 pump at 1260nm and a TM2 second harmonic at 630nm. A maximal power conversion of 2% is realized with an efficiency of 0.15%·W?1cm?2. We provide a modelling that demonstrates broadband features of GaN/AlGaN platform by showing second harmonic wavelengths tunability from the visible up to the near-infrared spectral region. We discuss drawbacks of modal phase matching and propose a novel solution which allows a drastic improvement of modal overlaps with the help of a planar polarity inversion. This new approach is compatible with low propagation losses and may allow as high as 100%·W?1cm?2 conversion efficiencies in the future. © 2017 Optical Society of America. |
Author-Keywords | |
Index-Keywords | Aluminum alloys, Efficiency, Gallium nitride, Harmonic analysis, Harmonic generation, Infrared devices, Molecular beam epitaxy, Nonlinear optics, Phase matching, Photosensitivity, Sapphire, Surface roughness, Waveguides, Low propagation loss, Modal phase matching, Near-infrared spectral regions, Polarity inversion, Power conversion, Propagation loss, Sapphire substrates, Second harmonics, Gallium alloys |
ISSN | 10944087 |
Link | Link |