Temperature stabilised operation of tunable fibre grating devices that use distributed on-fibre thin film heaters

An approach to achieving active electrical control and stabilisation of thermally tuned fibre grating devices that integrate thin film resistive heaters is introduced. In technique, the temperature dependence of the resistance of the heaters enables their simultaneous use as sensors to measure the temperature of the fibre. Supplying the devices with enough current to maintain a fixed resistance eliminates variations in the optical characteristics that can be caused by changes in the ambient temperature