We present reflective phase shifters based on high contrast gratings resting on a low-index spacer backed by a metallic mirror. The guided resonance of the grating combined with the reflection from the metallic mirror leads to an all-pass filter with 2π phase shift variation and unity reflectivity across the resonance. We present simulations, fabrication and measurement of passive devices fabricated in silicon over gold using a polymer as the spacer layer. Active control at high modulation speeds can be achieved by shifting the guided resonance wavelength using carrier injection or thermo-optic effect in silicon.

Date Published: 27 February 2015
PDF: 6 pages
Proc. SPIE 9372, High Contrast Metastructures IV, 93720W (27 February 2015); doi: 10.1117/12.2077744

Published in SPIE Proceedings Vol. 9372:
High Contrast Metastructures IV
Connie J. Chang-Hasnain; David Fattal; Fumio Koyama; Weimin Zhou, Editor(s)