Photonic integrated circuit structure with polarization device for high power applications

A structure comprising:

• a first waveguide with first end sections and a first coupling section between the first end sections, wherein the first waveguide comprises a first core;
• and
• a second waveguide having second end sections and a second coupling section between the second end sections and adjacent to the first coupling section, wherein the second waveguide comprises:
• a second core positioned laterally adjacent to the first core;
• and
• multiple additional second cores stacked vertically with the second core.

A structure comprising:

• a first waveguide having first end sections and a first coupling section between the first end sections, wherein the first waveguide comprises a first core;
• and
• a second waveguide having second end sections and a second coupling section between the second end sections and adjacent to the first coupling section, wherein the second waveguide comprises:
• a second core positioned laterally adjacent to the first core;
• and
• an additional second core stacked vertically with the second core, wherein, within the second coupling section, the second core and the additional second core are tapered and wherein at least one input/output port of at least one of the first core and the additional second core is tapered.