Lightwave circuit assembly having low deformation balanced sandwich substrate

摘要

A planar lightwave circuit assembly has an optical layer on a substrate. The substrate is attached to one face of a riser. A layer of a material having properties substantially the same as the substrate is attached to the other face of the riser. The layer of material counteracts the tendency of the assembly to bow as a result of differences in the coefficients of thermal expansion of the riser and substrate. This reduces stress-induced changes in performance characteristics of lightwave circuits in the optical layer.