Suspended germanium waveguides with subwavelength-grating metamaterial cladding for the mid-infrared band Academic Article uri icon

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abstract

  • 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.

authors

  • Sánchez-Postigo, Alejandro
  • Ortega-Moñux, Alejandro
  • Soler Penadés, Jordi
  • Osman, Ahmed
  • Nedeljkovic, Milos
  • Qu, Zhibo
  • Wu, Yangbo
  • Molina-Fernández, Íñigo
  • Cheben, Pavel
  • Mashanovich, Goran Z
  • Wangüemert-Pérez, J Gonzalo

publication date

  • May 24, 2021