Abstract

The insertion loss and size of semiconductor integrated optic circuits are major impediments to their use in optoelectronics. Insertion loss results from waveguide propagation, excess bend, and coupling losses. For many applications the device size is limited by the bend radius required for low radiation loss. Recent progress has focused on developing waveguides with large index differences Δn for compact low loss bends.^1-3 These structures, however, require small guide dimensions (<2.5 μm for 0.3-mm radii at λ = 1.5 μm) for singlemode operation, which increase the difficulty of fabrication and coupling to singlemode fibers. Here we introduce a novel waveguide structure to overcome these limitations.

© 1990 Optical Society of America