On-chip optical polarization controller

An optical polarization controller, comprising:

• a substantially planar substrate;
• and
• a waveguide unit cell formed on the substantially planar substrate, the waveguide unit cell comprising:
• a first out-of-plane waveguide portion, and
• a second out-of-plane waveguide portion coupled to the first out-of-plane waveguide portion, wherein each of the first and second out-of-plane waveguide portions respectively includes a core material layer arranged between a first optical cladding layer having a first stress-response property and a second optical cladding layer having a second stress-response property that is different than the first stress-response property such that each of the first and second out-of-plane waveguide portions is deflected by a deflection angle, wherein the deflection angle of at least one of the first out-of-plane waveguide portion or the second out-of-plane waveguide portion is configured to be adjustable in response to an electrical excitation, and wherein the at least one of the first out-of-plane waveguide portion or the second out-of-plane waveguide portion further comprises a piezoelectric actuator layer provided on the first or second optical cladding layers, the piezoelectric actuator layer being configured to expand or contract in response to an applied electric field.