Thermo-optical phase shifter

A thermo-optical phase shifter having a composite body including an optical waveguide that includes a core and clad and a heater that is attached to the optical waveguide, the thermo-optical phase shifter characterized in that

• the composite body has a bridge structure portion that is separated from a surface of a substrate by a gap and is arranged along the substrate surface, and a fixed portion that supports the bridge structure portion on the substrate and is continuous with both ends of the bridge structure portion;
• and
• the bridge structure portion has a curved shape in a plane along the surface of the substrate,
• wherein the optical waveguide reaches or exceeds 4% in a ratio of a difference between the refractive index of the core and the refractive index of the clad with respect to the refractive index of the core.

A thermo-optical phase shifter having a composite body including an optical waveguide that includes a core and clad and a heater that is attached to the optical waveguide, the thermo-optical phase shifter characterized in that

• the composite body has a bridge structure portion that is separated from a surface of a substrate by a gap and is arranged along the substrate surface, and a fixed portion that supports the bridge structure portion on the substrate and is continuous with both ends of the bridge structure portion;
• and
• the bridge structure portion has a curved shape in a plane along the surface of the substrate,
• wherein the thermo-optical phase shifter includes at least one support portion that supports the bridge structure portion on the substrate between both ends of the bridge structure portion;
• and
• wherein the optical waveguide has a length of 0.5 to 2 mm between the fixed portion and the support portion or between mutually adjoining two of the support portions.