Intermodal microwave-to-optical transduction using silicon-on-sapphire optomechanical ring resonator

Area of Science:

• Quantum optics
• Optomechanics
• Solid-state physics

Background:

• Optomechanical and electro-optomechanical systems are key for quantum transduction.
• Suspended designs limit efficiency due to poor heat dissipation.
• Interconnecting quantum modalities requires efficient microwave-to-optical conversion.

Purpose of the Study:

• To demonstrate an unsuspended optomechanical ring resonator (OMR) for microwave-to-optical frequency conversion.
• To address thermal limitations in suspended optomechanical systems.
• To present a silicon-on-sapphire (SOS) platform compatible with superconducting qubits.

Main Methods:

• Fabrication of an unsuspended optomechanical ring resonator on a silicon-on-sapphire platform.
• Utilizing triply resonant optical-to-optical conversion.
• Characterizing enhanced coupling rates and conversion efficiencies under microwave and optical drive powers.

Main Results:

• Achieved an enhanced coupling rate (Gb) of 3.6 GHz/√mW.
• Demonstrated a peak conversion efficiency of 1.2% with 3.6 mW microwave drive power.
• Obtained a microwave-to-optical conversion efficiency of 1.5 × 10⁻⁵ at 10 mW optical drive power.

Conclusions:

• The unsuspended SOS platform effectively mitigates thermal effects.
• This platform is compatible with superconducting qubits, crucial for quantum computing.
• The demonstrated OMR is a promising platform for optomechanical circuitry and quantum transduction.