Title :
Surface-Grating-Coupled Low-Loss Ge-on-Si Rib Waveguides and Multimode Interferometers
Author :
Nedeljkovic, Milos ; Penades, Jordi Soler ; Mitchell, Colin J. ; Khokhar, Ali Z. ; Stankovic, Stevan ; Dominguez Bucio, Thalia ; Littlejohns, Callum G. ; Gardes, Frederic Y. ; Mashanovich, Goran Z.
Author_Institution :
Optoelectron. Res. Centre, Univ. of Southampton, Southampton, UK
Abstract :
Germanium-on-silicon is a highly promising platform for planar photonics for the midinfrared, due to germanium´s wide transparency range. In this letter, we report Ge-on-Si waveguides with record low losses of only 0.6 dB/cm, which is achieved using a 2.9-μm thick germanium layer, thus minimizing mode interaction with dislocations at the germanium/silicon interface. Using these waveguides, multimode interferometers with insertion losses of only 0.21 ± 0.02 dB are also demonstrated.
Keywords :
diffraction gratings; germanium; infrared spectra; integrated optics; light interferometry; micro-optics; optical couplers; optical losses; optical waveguides; rib waveguides; silicon; Ge-Si; midinfrared spectra; mode interaction minimization; multimode interferometers; planar photonics; size 2.9 mum; surface-grating-coupled low-loss germanium-on-silicon rib waveguides; Couplers; Gratings; Loss measurement; Optical waveguides; Photonics; Propagation losses; Silicon; Mid-infrared; germanium; waveguides;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2015.2405611
