A dual-wavelength fiber Bragg grating sensing system by the use of a gain switched Fabry-Perot laser diode

摘要

The dual-wavelength-fiber-Bragg-gratings (DWFBGs) fabricated by writing two FBGs with different Bragg wavelengths at the same location of the fiber have been used as strain sensing elements in this work. In order to get high sensitivity, a dual-wavelength pulsed laser source is employed. An accuracy of 2% within /spl plusmn/50 /spl mu//spl epsiv/ range has been achieved.