Open AccessGermanium-on-silicon waveguides for long-wave integrated photonics: ring resonance and thermo-optics
Author(s) -
Dmitry A. Kozak,
Nathan F. Tyndall,
Marcel W. Pruessner,
William S. Rabinovich,
Todd H. Stievater
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.420687
Subject(s) - germanium , optics , optoelectronics , silicon photonics , materials science , photonic integrated circuit , resonator , photonics , silicon , waveguide , infrared , broadband , resonance (particle physics) , physics , particle physics
Germanium-on-silicon (GOS) represents the leading platform for foundry-based long-wave infrared photonic integrated circuits (LWIR PICs), due to its CMOS compatibility and absence of oxides. We describe ring resonance (Q-factors between 2×10 3 and 1×10 4 ) and thermo-optic tunability in germanium-on-silicon waveguides throughout the long-wave-infrared. The ring resonances are characterized by Q-factors and couplings that agree with measurements of propagation loss (as low as 6 dB/cm) and simulations and are enabled by broadband edge coupling (12dB/facet over a 3 dB bandwidth of over 4 microns). We demonstrate the furthest into the infrared that ring resonators have been measured and show the potential of this platform for photonic integration and waveguide spectroscopy at wavelengths from 7 microns to beyond 11 microns.