A fiber optic Fabry-Pérot accelerometer for low-frequency and weak vibration detection

Abstract

The detection of low‑frequency weak vibrations remains challenging due to the inadequate sensitivity of conventional accelerometers. To address this issue, this paper presents a fiber‑optic Fabry-Pérot (F‑P) MEMS accelerometer with ultra‑high sensitivity, designed for effective low‑frequency vibration measurement. The accelerometer features a novel double‑layer symmetric L‑shaped spring-mass structure integrated with a reflector‑enhanced film, which significantly improves sensitivity while suppressing cross‑axis interference. Experimental results show that the proposed accelerometer can detect vibrations down to 0.5  Hz, achieving a sensitivity of 1149.31  V/g and a noise floor of 20  ng/√Hz@100  Hz. These performance advances highlight its strong potential for short‑period seismic monitoring.