We demonstrate a reflective fiber-optic sensor with a core-diameter-mismatched fiber section and cladding-mode recoupling in a tilted fiber Bragg grating (TFBG). High-order cladding modes are efficiently excited by either a multimode fiber or a thin-core fiber section and recoupled back to the core mode by the TFBG. A special reflection spectrum with recoupling of cladding mode is then obtained to exploit the applications of evanescent waves in an optical fiber. Experimental results of the sensor to measure the external refractive index are presented.
- fiber Bragg grating (FBG)
- Fiber optics
- fiber-optic sensor
- refractive index sensor
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering