In this paper we demonstrated a fiber sensing system using the method of wavelength locking of two nearly identical fiber Bragg gratings (FBG) to interrogate the wavelength shift by directly measuring the intensity of the reflection from the sampling FBG. The light source of the sensing system is based on a fiber ring laser structure in which a reference FBG is used for locking the wavelength of the fiber ring laser pumped by a 980 nm laser diode to achieve lasing at 1555.85 nm. The wavelength locking method is able to an effective way of interrogating the wavelength shifting of a FBG by the intensity of the reflection from the sampling FBG, and is able to achieve real time sensing of the physical perturbations. In addition, the characteristics of the fiber sensing system for dynamic vibration and the key factors to acquire stable sensing are discussed.

Date Published: 22 April 2006
PDF: 7 pages
Proc. SPIE 6189, Optical Sensing II, 61890C (22 April 2006); doi: 10.1117/12.662377

Published in SPIE Proceedings Vol. 6189:
Optical Sensing II
Brian Culshaw; Anna G. Mignani; Hartmut Bartelt; Leszek R. Jaroszewicz, Editor(s)