Abstract

The Ti diffusion method is well known for making low-loss waveguides. However, the coupling and bending loss must be reduced for small-scale integration. These losses are mainly attributed to the asymmetric spot of waveguide.¹ A symmetric waveguide spot is appropriate for reducing both the coupling and the bending loss. To achieve this, several proposals such as MgO/Ti double diffusion have been made.² However, there is a trade off between reduction of loss and other switching performances.²

© 1990 Optical Society of America