Ultrasmall waveguide bends: the corner mirrors of the future?

Curved waveguides with strong lateral modal confinement have been fabricated on InGaAsP/InP by etching through the waveguide core. This has resulted in extremely sharp bends (radii as small as 30 Im) with negligible bend loss, enabling fabrication of very low loss 90" turns on a chip area as small as that of a corner mirror.