Simultaneous measurement of strain and temperature using Bragg gratings written in germanosilicate and boron-codoped germanosilicate fibers

A new fiber Bragg grating sensor configuration is presented for simultaneou s measurement of strain and temperature. The sensor utilizes the effect of boron codoping on the temperature dependence of the refractive index in ger manosilicate fibers. By writing gratings with close wavelengths in undoped and boron doped fibers, different temperature sensitivities are obtained wh ile strain sensitivities remain the same. These gratings are then spliced t o obtain a simple sensor head suitable for applications in smart structures and composite materials.