Optical phase shifter with one or more integrated thermoelectric devices

A method comprising:

• forming an optical phase shifter including a waveguide core having a first arm and a second arm laterally spaced from the first arm, wherein the first arm has a first side and a second side opposite from the first side, and the second arm has a third side adjacent to the first side of the first arm and a fourth side opposite from the third side;
• forming a first thermoelectric device including a first plurality of pillars and a second plurality of pillars that alternate with the first plurality of pillars in a series circuit, wherein the first plurality of pillars and the second plurality of pillars are disposed in the series circuit on the first side and the second side of the first arm of the waveguide core, the first plurality of pillars comprise an n-type semiconductor material, and the second plurality of pillars comprise a p-type semiconductor material;
• and
• forming a second thermoelectric device including a third plurality of pillars and a fourth plurality of pillars that alternate with the third plurality of pillars in a second series circuit, wherein the third plurality of pillars and the fourth plurality of pillars of the second thermoelectric device are disposed in the second series circuit on the third side and the fourth side of the second arm of the waveguide core, the third plurality of pillars comprise the n-type semiconductor material, and the fourth plurality of pillars comprise the p-type semiconductor material.