%0 Journal Article
%A Sánchez-Postigo, Alejandro
%A Ortega-Moñux, Alejandro
%A Soler Penadés, Jordi
%A Osman, Ahmed
%A Nedeljkovic, Milos
%A Qu, Zhibo
%A Wu, Yangbo
%A Molina-Fernández, Íñigo
%A Cheben, Pavel
%A Mashanovich, Goran Z
%A Wangüemert-Pérez, J Gonzalo
%T Suspended germanium waveguides with subwavelength-grating metamaterial cladding for the mid-infrared band.
%D 2021
%U http://hdl.handle.net/10668/18030
%X 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.
%~