Monolithically integrated passive photonic silicon chip for nano-g level acceleration tri-axial detection

Area of Science:

• Photonics
• Microelectromechanical Systems (MEMS)
• Sensor Technology

Background:

• Accurate measurement of low-frequency acceleration vectors is crucial for various applications.
• Existing accelerometers often face limitations in sensitivity, size, or tri-axial consistency.
• Photonic sensing offers potential advantages due to its immunity to electromagnetic interference and high resolution.

Purpose of the Study:

• To propose and demonstrate a monolithically integrated tri-axial passive photonic accelerometer chip.
• To achieve nano-g level resolution for low-frequency acceleration measurements.
• To ensure tri-axial consistency and minimize transverse crosstalk.

Main Methods:

• Utilized uniform silicon-based micromachining for chip fabrication.
• Designed compact gradient-type and asymmetric S-type spring beams for enhanced sensitivity.
• Employed a fiber-based Fabry-Perot interferometer (FPI) for optical phase change demodulation.

Main Results:

• Achieved high sensitivity (>43.6 dB for X/Y, >42.8 dB for Z) within the 1-80 Hz bandwidth.
• Demonstrated average minimum detectable accelerations (MDAs) as low as 21.80 ng/Hz^1/2 (X-axis).
• Maintained low transverse crosstalk below 2.07% for all axes.

Conclusions:

• The proposed tri-axial photonic accelerometer chip exhibits excellent performance for low-frequency acceleration vector detection.
• The monolithic integration and silicon micromachining approach simplify fabrication and improve yield.
• This technology holds promise for applications requiring high-precision, low-frequency acceleration sensing.