Open AccessSuspended germanium waveguides with subwavelength-grating metamaterial cladding for the mid-infrared band
Author(s) -
Alejandro SánchezPostigo,
Alejandro OrtegaMoñux,
Jordi Soler Penadés,
A. M. Osman,
Milos Nedeljkovic,
Zhipeng Qu,
Yangbo Wu,
Í. Molina-Fernández,
Pavel Cheben,
Goran Z. Mashanovich,
J. Gonzalo WangüemertPérez
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.422764
Subject(s) - germanium , materials science , cladding (metalworking) , optics , optoelectronics , metamaterial , infrared , fabrication , grating , wavelength , photonics , physics , medicine , alternative medicine , pathology , silicon , metallurgy
In recent years, sensing and communication applications have fueled important developments of group-IV photonics in the mid-infrared band. In the long-wave range, most platforms are based on germanium, which is transparent up to ∼15-µm wavelength. However, those platforms are limited by the intrinsic losses of complementary materials or require complex fabrication processes. To overcome these limitations, we propose suspended germanium waveguides with a subwavelength metamaterial lateral cladding that simultaneously provides optical confinement and allows structural suspension. These all-germanium waveguides can be fabricated in one dry and one wet etch step. A propagation loss of 5.3 dB/cm is measured at a wavelength of 7.7 µm. These results open the door for the development of integrated devices that can be fabricated in a simple manner and can potentially cover the mid-infrared band up to ∼15 µm.