(1) Key Laboratory of Fiber Optic Sensing Technology and Information Processing, Ministry of Education of China, Wuhan University of Technology, Wuhan, 430070, China
Abstract:
The effects of linear and quadratic strain on the reflective spectrum of FBG and the transmission spectrum of LPFG have been numerically investigated based on the coupled -mode equations. The results show that for the FBG or LPFG undergo-ing only linear strain, the reflection or transmission spectrum is symmetrical about its central wavelength, the dependence relationships of the central wavelength shift, full-width-at-half-maximum, peak intensity upon the strain gradient have been obtained.