Low-Loss Surface-Mode Waveguides for Terahertz Si–SiGe Quantum Cascade Lasers

Author

De Rossi, Alfredo ; Carras, Mathieu ; Paul, Douglas J.

Author_Institution

Thales Res. & Technol. France, Palaiseau

Volume

42

Issue

12

fYear

2006

Firstpage

1233

Lastpage

1238

Abstract

A new design of low-loss terahertz waveguide for Si-SiGe quantum-cascade lasers (QCLs) is presented. Periodic surface gratings are used to define waveguides without the requirement of cleaved or etched end facets. As Si cleaves along the (111) planes and not in the vertical direction for standard Si (100) substrates, this significantly aids the fabrication of waveguides. Losses down to 2 cm^-1 with modal overlap of 0.4 can be achieved for shallow gratings with etched depths of only 0.56 mum for an active material layer thickness of 8 mum. Such low loss and high modal overlap is key to any Si-SiGe QCL being realized

Keywords

Ge-Si alloys; diffraction gratings; elemental semiconductors; etching; laser modes; optical losses; quantum cascade lasers; silicon; submillimetre wave lasers; waveguide lasers; 0.56 mum; 8 mum; Si; Si (100) substrates; Si cleaving; Si-SiGe; Si-SiGe lasers; etching; laser design; low-loss waveguides; modal overlap; periodic surface gratings; quantum cascade lasers; shallow gratings; surface-mode waveguides; terahertz lasers; Free electron lasers; Optical scattering; Optical surface waves; Optical waveguides; Plasmons; Quantum cascade lasers; Silicon germanium; Surface emitting lasers; Surface waves; Waveguide lasers; Laser; SiGe; silicon; terahertz; waveguide;

fLanguage

English

Journal_Title

Quantum Electronics, IEEE Journal of

Publisher

ieee

ISSN

0018-9197

Type

jour

DOI

10.1109/JQE.2006.883496

Filename

4015581