Ultra-compact high transmittance photonic wire bends for monolithic integration on III/V-semiconductors

Using deeply etched photonic wires on gallium arsenide, ultra-small bent waveguides with radii of curvature below 1 mm were fabricated. The maximum transmittance of a 90 degrees bend with radius of 2 μm can be enhanced to almost 99% at a wavelength of 1.55 μm, which corresponds to an attenuation factor of 0.05 dB per bend.