High temperature, stable fiber Bragg gratings

Optical fiber Bragg gratings (FBGs) have proven to be useful in many different applications, but particularly in telecommunications and as major components in optical sensor systems. One weakness of the fiber grating in sensor systems has been its thermal erasure at high temperatures. Fiber gratings stable at high temperatures could be used to monitor the curing of composite structures or in other high temperature sensing applications. We have developed a process to fabricate FBGs which show no decrease in performance over 10 days at 600/spl deg/C.