Low-loss spiral waveguides with ultra-small footprint on a micron scale SOI platform

Abstract

We have recently characterized spirals waveguides based on 4 μm thick strip waveguides with suitably designed lowloss micron scale bends. Different bends and different lengths have been tested to extrapolate propagation losses and bending losses. In particular lowest bending losses have been found to be smaller than 0.01 dB per turn, while propagation losses are about 0.15 dB/cm. Very small footprint is achieved thanks to a novel bend concept combined to waveguide pitches of a few microns. The unique properties of our waveguides make our platform the ideal one for low loss long spiral waveguides with very small footprint.