Accelerometer Employing a Side-Hole Fiber in a Sagnac Interferometer

An optical accelerometer realized with a new side-hole fiber in a Sagnac interferometric scheme, was developed by utilizing the birefringent and stiffness properties of the optical fiber to achieve a high sensitivity, a broad frequency range, a wide acceleration range, and an excellent linearity. The proposed accelerometer exhibits a resonant frequency of 2300 Hz and an average sensitivity of 44.3 (+/- 3.0) pm/g over a broad frequency range from 4 to 900 Hz. The linearity of the signal response exceeds 99.9% and its transverse sensitivity is less than 11% of the main axis. It exhibits a dynamic acceleration range of 62.5 dB which is related to the applied acceleration from 0.03 to 40 g, making the side-hole fiber a good candidate for acceleration/vibration sensing applications. Furthermore, the tradeoff relationship between the sensitivity and the resonant frequency was significantly improved when compared to that of fiber Bragg grating-based accelerometers.