Tilted Fiber Bragg Grating Sensors

Abstract

By inducing a tilted angle between the grating and the normal direction of optical fibers, tilted fiber Bragg grating (TFBG) provides an effective means to lead the forward-propagating input light to the backward-propagating cladding modes and the core mode. Taking advantage of novel configurations and functional material coating, TFBG can be used as a powerful lab-on-fiber component for various measurements of mechanical, electrical, magnetic, biological, medical, and chemical parameters. In this paper, we present a brief review of TFBG sensing technology, including TFBG fabrication, mode coupling theory, sensing principle properties (especially the surface plasmon sensing technology). Recent progresses in various applications are discussed. These applications include mechanical sensing (bending, vibration, micro-displacement), electromagnetic sensing (electric field, magnetic field), biological sensing (cell density, protein, glucose) and chemical sensing (gas, electroactive microbe). Thanks to the multidisciplinary cooperation, especially the great progress of functional materials and nanotechnologies, the future of TFBG is promising in advanced and practical sensing.