Low-Cost Fiber Optic Cantilever Accelerometer With a Spherical Tip Based on Gaussian Beam Focusing

Lianjin Hong,Mingze Wu,Yue Li,Yongyao Chen

doi:10.1109/jphot.2021.3099827

Lianjin Hong, Mingze Wu + Show 2 more

Open Access

https://doi.org/10.1109/jphot.2021.3099827

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Abstract

We propose and demonstrate a low-cost and simple fiber optic cantilever accelerometer with a spherical tip based on Gaussian beam focusing. The accelerometer consists of ceramic ferrule, ceramic sleeve, receiving fiber and emitting fiber, where both fibers are single mode fiber, the ferrule and sleeve have characteristics of high precision, which reduce the difficulty of optical alignment. The end of the emitting fiber is made into a spherical tip for focusing the Gaussian beam to improve sensitivity. When the accelerometer is in operation, the emitting fiber acts as a cantilever beam, the acceleration can be measured by detecting the transmission power. Further, our experimental results show that the spherical fiber tip can improve the acceleration sensitivity by 67% over 10 Hz-1000 Hz without reducing the working bandwidth. In addition, it is found that the fiber accelerometer has a high signal-to-noise ratio (SNR) up to 60 dB, and a low harmonic distortion of better than -30 dB, rendering a quasi-8-shaped directionality at the working frequency ranging from 10 Hz to 1200 Hz. This clever sensor structure may have potentials for developing high-performance and cost-effective accelerometers and hydrophones.

Highlights

A CCELEROMETERS play an important role in scientific research and various industrial fields such as robots, environmental surveillance, navigation systems and underwater acoustics [1]–[4]
We proposed a fiber optic cantilever accelerometer with a spherical tip based on Gaussian beam focusing
We demonstrated a fiber spherical tip accelerometer

Summary

INTRODUCTION

A CCELEROMETERS play an important role in scientific research and various industrial fields such as robots, environmental surveillance, navigation systems and underwater acoustics [1]–[4]. The accelerometer needs to set the initial operating point This fiber cantilever sensor has a simple structure but complex operation. Dass et al studied a high sensitivity fiber cantilever acoustic sensor based on direct light power measurement [9]. A vibration sensor with compact structure, low cost, high sensitivity and simple operation is desired. We proposed a fiber optic cantilever accelerometer with a spherical tip based on Gaussian beam focusing. The clever structural design enables it to have simple structure and low cost It consists of a receiving fiber and an emitting fiber, which are encapsulated with ceramic ferrule and sleeve (Fig. 1). An emitting fiber acts as a cantilever beam responding to the acceleration, and its free end has a spherical tip to focus Gaussian Beam. It is found that the fiber accelerometer has a high SNR up to 60 dB, and a low harmonic distortion of better than −30 dB, rendering a quasi-8-shaped directionality at the working frequency from 10 Hz to 1200 Hz

THEORY ANALYSIS

EXPERIMENT

Findings

CONCLUSION AND DISCUSSION