Thermo-optic devices providing thermal recirculation

A thermal-optic device comprising:

• a waveguide comprising an input section, an output section, and a thermal tuning section having a path length between the input section and the output section, the waveguide having a surface area defined by the path length and a width of the thermal tuning section, the waveguide further including a cladding layer and a core layer provided on the cladding layer, the core layer having a first refractive index and the cladding layer having a second refractive index less than the first refractive index, a difference between the first refractive index and the second refractive index being greater than 0.5;
• and
• a thermal device in thermal communication with the thermal tuning section of the waveguide, the thermal device having a surface area, wherein a ratio of the surface area of the thermal device to the surface area of the waveguide is less than 5.

16-22. (canceled)

A waveguide optical device in accordance with claim 16, wherein the cladding layer is a first cladding layer, the waveguide optical device further including a second cladding layer provided on the core layer.

A waveguide optical device in accordance with claim 16, wherein the core layer includes a material selected from the group consisting of:

• silicon, silicon nitride, silicon oxynitride, silicon oxycarbide, germanium doped silicon, indium phosphide, and gallium arsenide.

A waveguide optical device in accordance with claim 16, wherein the cladding layer includes silica.