High-frequency GaAs optomechanical bullseye resonator

The integration of optomechanics and optoelectronics in a single device opens new possibilities for developing information technology and exploring fundamental phenomena. Gallium arsenide is a well-known material that can bridge the gap between the functionalities of optomechanical devices and optical gain media. Here, we experimentally demonstrate a high-frequency GaAs optomechanical resonator with a ring-type bullseye geometry that is unprecedented in this platform. We measured mechanical modes up to 3.4 GHz with quality factors of 4000 (at 77 K) and reached optomechanical coupling rates up to 39 kHz at telecom wavelengths. The temperature dependence of mechanical losses was assessed and demonstrate the efficiency and anisotropy resilience of the bullseye anchor loss suppression. Such characteristics are valuable for active optomechanics, coherent microwave-to-optics conversion via piezo-mechanics and other implementations of high-frequency oscillators in III-V materials.