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

Volume

27

Issue

10

fYear

2015

fDate

May15, 15 2015

Firstpage

1040

Lastpage

1043

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;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2015.2405611

Filename

7045441