Patent ID: 7206473

Claim:
An optical module comprising: a silica-based optical waveguide circuit comprising a 1×N thermo-optic effect optical switch with one input and N outputs, where N is an integer equal to or greater than three; and a driving electronic circuit for providing said optical waveguide circuit with a refractive index variation to modify an optical output characteristic, said driving electronic circuit being mounted on a silica-based substrate of said optical waveguide circuit together with said optical waveguide circuit, said 1×N thermo-optic effect optical switch comprising: one silica-based input waveguide placed on the substrate of said optical waveguide circuit; N silica-based output waveguides placed on the substrate of said optical waveguide circuit; N silica-based gate optical switches, each of which is connected to one of said N output waveguides on the substrate of said optical waveguide circuit, for controlling passing of light; and a plurality of 1×2 optical switches placed between said input waveguide and said gate optical switches, for continuously switching its path in response to a level of an electrical signal from driving power supply circuit in said driving electronic circuit, wherein said plurality of 1×2 optical switches are divided into a plurality of groups, each of which is assigned one of said driving power supply circuits, and said optical module further comprises electrical digital switches incorporated into integrated circuits (ICs) for controlling levels of electrical signals supplied from said driving power supply circuits to said plurality of 1×2 optical switches so as to energize only one group of the plurality of groups of optical switches.