Lightwave circuit assembly having low deformation balanced sandwich substrate
AssigneeLightwave Microsystems Corporation
InventorsKenneth McGreer, Peter D. Ascanio, Maria Guardado, Randal E. Zugnoni
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Abstract
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.
Claims30
A planar lightwave circuit assembly comprising:
- a riser having a first coefficient of thermal expansion;
- a substrate affixed to a first face of the riser, the substrate having a second coefficient of thermal expansion different from the first coefficient of thermal expansion;
- an optical layer comprising a lightwave circuit on the substrate;
- and,
- a layer of material affixed to a second face of the riser opposed to the first face, the layer of material having a third coefficient of thermal expansion different from the first coefficient of thermal expansion;
- wherein the second and third coefficients of thermal expansion are either both greater than the first coefficient of thermal expansion or both less than the first coefficient of thermal expansion, and the third coefficient of thermal expansion is between the first and second coefficients of thermal expansion, and
- the layer of material is at least one of thicker than the substrate and stiffer than the substrate.
A planar lightwave circuit assembly comprising:
- a riser;
- a substrate having a coefficient of thermal expansion;
- an optical layer comprising a lightwave circuit on the substrate;
- first adhesive means for affixing the substrate to the riser;
- a layer of material having a coefficient of thermal expansion substantially the same as the coefficient of thermal expansion of the substrate;
- and,
- second adhesive means for affixing the layer of material to the riser.
Dependencies are inferred from the claim text.