Fabry Perot Accelerometor Produced By 193nm Laser

Acceleration sensor is very important, which is broad applied in aerospace, geological prospecting, civil structure vibration measurement fields. Meanwhile, fiber Fabry-Perot sensors could offer a series of advantages, such as free from electromagnetic interference, corrosion resistance, small size, high sensitivity etc. Based on Fabry-Perot strain sensors made of laser manufacturing, a fiber Fabry-Perot accelerometer is designed and implemented in this paper, which meet the needs of aircraft structure vibration monitoring and the monitoring of the generator of the power station.The fabrication process of F-P air cavity using 193 nm laser micromachining is investigated. Single cavity and double cavity F-P sensors are developed in this paper and the sensors characteristics are also tested. The results show that the thermal coefficient and the static strain sensitivity of single F-P cavity are 1.1°pm C and 1.61 pm με, respectively. And the thermal coefficient of a double F-P cavity structure is 9.7°pm C.Based on the two-end fixed beam structure, an optical fiber F-P accelerometer is proposed in this paper. From the perspective of structural mechanics, a two-end fixed beam structure mechanical property is researched in theory. The structure modal analysis and static analysis are simulated using ANSYS software. Strain sensitivity in different directions and resonant characteristics, the mass centre of gravity position on the influence of natural frequency are simulated. Finally, an optical fiber F-P sensing head and a two-end fixed beam are encapsulated. Then an insensitive to temperature accelerometer is assembled, which can be applied to low frequency acceleration measurement and the range measurement is ?8 ?8 g. The frequency response and sensitivity of the accelerometer are tested. The test results show that the sensitivity is 0.13 rad/g and the frequency is 0 70 Hz, which is basically unchanged in the frequency range of 0-60 Hz.