US Patent 10101531 Polarization mode converter

A polarization mode converter includes a rectangular waveguide, a first tapered waveguide, and a second tapered waveguide. A height of the rectangular waveguide is a first height (H1). A side of the first tapered waveguide is coupled to the rectangular waveguide. A width of the first tapered waveguide changes gradually. A height of the first tapered waveguide is a second height (H2), and H2 is less than H1. The second tapered waveguide is detached from the rectangular waveguide and the first tapered waveguide. A width of the second tapered waveguide changes gradually. A height of the second tapered waveguide is H1. The first tapered waveguide is located between the rectangular waveguide and the second tapered waveguide.