Open AccessLow loss SiGe graded index waveguides for mid-IR applications
Author(s) -
M. Brun,
P. Labeye,
G. Grand,
JeanMichel Hartmann,
Fahem Boulila,
Mathieu Carras,
S. Nicoletti
Publication year - 2014
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.000508
Subject(s) - photonics , materials science , fabrication , optoelectronics , stack (abstract data type) , optics , photonic integrated circuit , electronic circuit , waveguide , wavelength , refractive index , silicon photonics , computer science , electrical engineering , physics , engineering , medicine , alternative medicine , pathology , programming language
In the last few years Mid InfraRed (MIR) photonics has received renewed interest for a variety of commercial, scientific and military applications. This paper reports the design, the fabrication and the characterization of SiGe/Si based graded index waveguides and photonics integrated devices. The thickness and the Ge concentration of the core layer were optimized to cover the full [3 - 8 µm] band. The developed SiGe/Si stack has been used to fabricate straight waveguides and basic optical functions such as Y-junction, crossings and couplers. Straight waveguides showed losses as low as 1 dB/cm at λ = 4.5 µm and 2 dB/cm at 7.4 µm. Likewise straight waveguides, basic functions exhibit nearly theoretical behavior with losses compatible with the implementation of more complex functions in integrated photonics circuits. To the best of our knowledge, the performances of those Mid-IR waveguides significantly exceed the state of the art, confirming the feasibility of using graded SiGe/Si devices in a wide range of wavelengths. These results represent a capital breakthrough to develop a photonic platform working in the Mid-IR range.