Low-loss, high-δ, single-mode channel waveguides for high-density integrated optical devices

Low-loss, high-δ, single-mode channel waveguides having cores of SiO2-Ta2O5 mixture film are successfully fabricated using sputtering and reactive ion-beam etching. Propagation loss is less than 0.6dB/cm, and no bending loss for 500μm curvature radius at 1.3μm wavelength is achieved for an optical waveguide having a relative index difference of 5.6%.