• Mashanovich, Goran Z.
• Wu, Yangbo
• Molina-Fernández, Íñigo
• Ortega-Moñux, Alejandro
• Wangüemert-Pérez, J. Gonzalo
• Nedeljković, Miloš
• Sánchez-Postigo, Alejandro
• Cheben, Pavel
• Qu, Zhibo
• Osman, Ahmed

Abstract

<p>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. </p>

Topics

• impedance spectroscopy
• metamaterial
• Germanium