title: GaAs-based air-slot photonic crystal nanocavity for optomechanical oscillators.
abstract: We theoretically investigate an optomechanical structure consisting of two parallel GaAs membranes with an air-slot type photonic crystal nanocavity. The optical cavity has a quality factor of 4.8 × 106at 1.52 μm and an extremely small modal volume of 0.015 of a cubic wavelength for the fundamental mode in a vacuum. The localized electric field near the air/dielectric-object boundary provides a large optomechanical coupling factor of ~990 GHz/nm. The fundamental mechanical mode resonance is 95 MHz and a quality factor is 83,800 at room temperature, nearly seven times higher than that for a similar Si-based structure. This high mechanical quality factor of a GaAs-based structure stems from low thermoelastic loss and leads to more effective optical control of nanomechanical oscillators.
authors.affiliation: Institute of Industrial Science, The University of Tokyo, Tokyo 153-8505, Japan. nomura@iis.u-tokyo.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nomura
mesh_terms: D000388:Air; D001152:Arsenicals / Q000737:chemistry*; D003460:Crystallization / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005708:Gallium / Q000737:chemistry*; D055617:Micro-Electrical-Mechanical Systems / Q000295:instrumentation*; D036103:Nanotechnology / Q000295:instrumentation*; D009991:Oscillometry / Q000295:instrumentation*; D017785:Photons; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D001152:Arsenicals; C043055:gallium arsenide; D005708:Gallium