Very low loss GaAs/AlGaAs miniature bending waveguide with curvature radii less than 1 mm

Very low loss GaAs/AlGaAs miniature bending waveguides with curvature radii less than 1 mm have been fabricated. Their propagation characteristics have been measured at wavelengths of 1.30 and 1.55 μm. Total loss of the fabricated S-bending waveguide shows no increase due to radiation loss even at small radii less than 1 mm. The measured total loss at a radius of 500 μm, for example, is 0.55 and 1.4 dB at wavelengths of 1.30 and 1.55 μm, respectively. These very low loss bending waveguides with small radii prove to be suitable for compact optical integrated circuits.