Optical loss measurements on GaAs/GaAlAs single-mode waveguide Y-junctions and waveguide bends

The propagation losses in GaAs/GaAlAs double heterostructure single-mode waveguide symmetrical Y-junctions were measured as a function of the full angle α of the Y-junction. It was found that it was possible experimentally to identify whether the Y-junction waveguide was single mode. The bending loss in bent waveguides, due to the change in the axial direction of the waveguide, was measured as a function of the bending angle α/2. It was also experimentally confirmed that the bending loss was significantly reduced by increasing the lateral optical field confinement, i.e., by increasing the etch depth of the rib waveguide