Temperature insensitive long-period fibre gratings

Novel temperature insensitive long-period fibre gratings are presented. The temperature sensitivity of long-period gratings (LPGs) can be completely eliminated by manipulating the refractive index of the outer cladding. The blue shift of the LPGs combined with a red shift caused by the recoating material have resulted in a temperature sensitivity of 0.07 nm/100/spl deg/C.