Silicon carbide double-microdisk resonator.

Area of Science:

• Optoelectronics
• Nanotechnology
• Materials Science

Background:

• Silicon carbide (SiC) is a promising material for optomechanical devices due to its excellent optical and mechanical properties.
• Microdisk resonators offer compact footprints and high optical quality factors, enabling strong light-matter interactions.

Purpose of the Study:

• To demonstrate the first silicon carbide double-microdisk resonator (SiC DMR).
• To investigate the optomechanical properties and thermal-Brownian motion of SiC DMRs at room temperature.
• To explore the potential of SiC DMRs for low-power optomechanical sensing in harsh environments.

Main Methods:

• Fabrication of a SiC double-microdisk resonator using a multi-layer nanofabrication process.
• Characterization of the optical quality (Q factor) of the SiC DMR.
• Direct observation of thermal-Brownian motion of mechanical modes at room temperature.
• Measurement of mechanical quality factors and investigation of optomechanical interactions.

Main Results:

• Successful fabrication of a SiC DMR with a radius of 24 μm operating in the ITU high frequency range.
• Achieved high optical quality factors (Q∼10⁵) for the SiC DMR.
• First direct observation of thermal-Brownian motion of mechanical modes in a SiC DMR at room temperature.
• Observed fundamental/second-order common modes and fundamental differential (D1) modes, with D1 modes showing high mechanical quality (>3800) at 18.4 MHz in vacuum.
• Demonstrated linear and nonlinear optomechanical spring effects at sub-milliwatt optical power.

Conclusions:

• The developed SiC DMR exhibits excellent optical and mechanical properties.
• SiC DMRs enable direct observation of thermal-Brownian motion and optomechanical effects at room temperature and low optical power.
• SiC DMRs hold significant potential for developing robust, low-power optomechanical sensors for demanding applications.