A Nano-g Fabry–Pérot Damped Accelerometer Featuring All-Metal-Elastic Fiber Optics Technology With 112-dB Dynamic Range

In the critical applications of geological disaster prediction, aerospace, and other fields, the development of accelerometers is increasingly trending toward higher precision, larger dynamic range, and miniaturization. Although the existing MEMS or some optical devices already possess these advantages, the majority of devices reported typically require the difficulty and complex technology in the manufacturing process. Such as the creation of ultrathin cantilever beam structures to the pursuit of high sensitivity often results in devices are fragile and unreliable. This article presents a Fabry-Pérot (F-P) damped all-metal-elastic fiber-optic accelerometer that utilizes the optical interference detection method to convert the input acceleration into displacement. The all-metal hard friction design required careful consideration of friction-induced insensitivity. To mitigate this, high-precision laser cutting and polishing techniques were used to accurately process materials like brass. The results shown that the proposed accelerometer exhibits the overall noise floor of 21 ng/ $\surd $ Hz at 92 Hz, with a measurement range of 8.4 mg and a dynamic range of 112 dB, which is the superior level for this frequency band in the existing damped accelerometers as far as we know, and it maintains a small overall volume (about 25 cm3). Compared with reported devices, the device proposed uses all-metal-elastic materials can greatly reduce the material and manufacturing cost and enhance the durability and reliability of the device, overcoming the limitations of traditional MEMS and optical devices. Therefore, the proposed accelerometer is expected to be used in practical applications, such as earthquake monitoring, navigation and other complex environments.