Passive On-Chip Tri-Axial Fiber-Optic Accelerometer with Nano-g Level Noise Floor

Accelerometers have attracted significant attention for their versatile applications. Fiber-optic accelerometers demonstrate excellent potential for low noise and strong electromagnetic immunity due to their passive nature. They are generally classified as intensity-modulated [1], wavelength-modulated [2], or phase-modulated [3] based on operating principles. Currently, the demand for low-noise, high-consistency tri-axial accelerometers in the low-frequency band is increasing, but traditional manual assembly often leads to poor consistency and assembly errors. Integrated tri-axial accelerometers face low yields and performance limitations. This paper integrates tri-axial sensing units into a passive silicon chip and optimizes the structure to simplify fabrication and improve yield, resulting in a monolithically-integrated fiber-optic accelerometer with nano-g level noise floor.