Packaging to reduce thermal gradients along the length of long fiber gratings

We have reduced the effect of thermal gradients across a fiber grating-based dispersion compensation module by embedding the grating in a thermal conductor surrounded by a thermal insulator, which keeps the grating length at a nearly uniform temperature. We modeled the package performance with finite-element methods and confirmed the results experimentally. We have found no measurable perturbation in the device dispersion during thermal testing, even as 80/spl deg/C thermal gradients were imposed across the module.