Coarse-to-fine optical MEMS accelerometer design and simulation.

Area of Science:

• Physics
• Electrical Engineering
• Materials Science

Background:

• Microelectromechanical systems (MEMS) accelerometers are crucial for motion sensing.
• Fabry-Pérot (FP) interferometers offer high sensitivity for optical measurements.
• Existing MEMS accelerometers face limitations in sensitivity and linear range.

Purpose of the Study:

• To propose a novel coarse-to-fine optical MEMS accelerometer.
• To enhance accelerometer sensitivity and linear measurement range.
• To reduce cross-axis sensitivity in MEMS accelerometers.

Main Methods:

• Design of a MEMS accelerometer utilizing two Fabry-Pérot cavities.
• Implementation of a coarse-to-fine measurement strategy.
• Application of the dual wavelength method for enhanced performance.
• Optical simulation for performance evaluation.

Main Results:

• Achieved a 10x increase in sensitivity compared to single FP cavity designs.
• Demonstrated reduced cross-axis sensitivity due to insensitivity to orthogonal displacements.
• Simulated mechanical sensitivity of 190 nm/g and optical sensitivity of 8 nm/g.
• Obtained a linear measurement range of ±5g with a first resonance frequency of 1141 Hz.

Conclusions:

• The proposed optical MEMS accelerometer design significantly improves sensitivity and linear range.
• The dual wavelength and coarse-to-fine methods effectively enhance accelerometer performance.
• The fiber-coupled optical system facilitates fabrication and reduces cross-axis sensitivity.