Microdisplacement Sensor Based on Tilted Fiber Bragg Grating Transversal Load Effect

In this paper, a simple and novel micro-displacement sensor based on tilted fiber Bragg grating (TFBG) is proposed and studied. The transversal compression imposed on TFBG causes the changes of grating angle, index, and length, resulting in a considerable spectrum change of the cladding modes. The spectrum amplitude, extinction ratio, and central wavelength are analyzed with the change of the transversal compression. These three parameters are found to have repeatable linear relationship with the transversal load. Moreover, the extinction ratio exhibits a high displacement sensitivity of 18 dB/mm.