Characteristics of heat flow in optical fiber devices that use integrated thin-film heaters

We describe the analysis of heat flow in a type of tunable optical fiber gr ating that uses thin-film resistive heaters microfabricated on the surface of the fiber. The high rate of heat loss from these microstructures and the relatively low thermal diffusivity of the glass yield unusual thermal prop erties. Approximate one-dimensional analytical calculations capture importa nt aspects of the thermal characteristics of these systems. Comparison with experimental results that we obtained from devices with established design s validates certain features of the computations. This modeling also establ ishes the suitability of integrated thin-film heaters for several new types of tunable fiber grating devices. (C) 2000 Optical Society of America OCIS codes: 060.2340, 060.4510, 230.1480, 230.3990.