High-sensitivity on-chip accelerometer based on a coupling-modulation whispering gallery mode microcavity.

Area of Science:

• Photonics
• Microelectromechanical systems (MEMS)
• Optical sensing

Background:

• High-quality factor whispering-gallery-mode (WGM) optical microcavities are suitable for accelerometers.
• Existing WGM accelerometers have limitations like large footprints and poor stability due to off-chip components and coupling methods.

Purpose of the Study:

• To develop a novel on-chip accelerometer.
• To overcome the limitations of conventional WGM accelerometers.
• To leverage a coupling-modulation WGM microring resonator on a standard SOI platform.

Main Methods:

• Fabrication of an on-chip accelerometer using a coupling-modulation WGM microring resonator on a Silicon-on-Insulator (SOI) platform.
• Utilizing an integrated cantilever beam whose vibration, induced by acceleration, modulates a Mach-Zehnder interferometer (MZI) phase shift.
• Translating the MZI phase shift into output intensity variations by modulating the coupling condition.

Main Results:

• Achieved a noise-equivalent acceleration of 10 ng/√Hz.
• Demonstrated a compact footprint of 10.5 mm × 15 mm.
• The on-chip design provides precise and stable control of the spectral response.

Conclusions:

• The proposed on-chip accelerometer overcomes limitations of existing devices.
• The CMOS-compatible monolithic architecture ensures robustness and scalability.
• The device shows strong potential for large-scale integrated optical sensing applications.