1 GHz electro-optical silicon-germanium modulator in the 5-9 µm wavelength range
Thi Hao Nhi Nguyen, Natnicha Koompai, Victor Turpaud, Miguel Montesinos‐Ballester, Jonathan Peltier, Jacopo Frigerio, Andrea Ballabio, Raffaele Giani, Jean‐René Coudevylle, Cédric Villebasse, David Bouville, Carlos Alonso-Ramos, Laurent Vivien, Giovanni Isella, Delphine Marris‐Morini
Abstract
Spectroscopy in the mid-infrared (mid-IR) wavelength range is a key technique to detect and identify chemical and biological substances. In this context, the development of integrated optics systems paves the way for the realization of compact and cost-effective sensing systems. Among the required devices, an integrated electro-optical modulator (EOM) is a key element for advanced sensing circuits exploiting dual comb spectroscopy. In this paper, we have experimentally demonstrated an integrated EOM operating in a wide wavelength range, i.e. from 5 to 9 µm at radio frequency (RF) as high as 1 GHz. The modulator exploits the variation of free carrier absorption in a Schottky diode embedded in a graded silicon germanium (SiGe) photonic waveguide.