Optical modulation in Ge-rich SiGe waveguides in the mid-infrared wavelength range up to 11 µm
Miguel Montesinos‐Ballester, Vladyslav Vakarin, Joan Manel Ramírez, Qiankun Liu, Carlos Alonso‐Ramos, Xavier Le Roux, Jacopo Frigerio, Andrea Ballabio, Andrea Barzaghi, Lucas Deniel, David Bouville, Laurent Vivien, Giovanni Isella, Delphine Marris‐Morini
Abstract
Abstract Waveguide integrated optical modulators in the mid-infrared wavelength range are of significant interest for molecular spectroscopy. This is because on-chip synchronous detection can improve the performance of detection systems and can also be used for free-space communications where optical modulators working in atmospheric transparency windows are needed. Here we report optical modulation in a mid-infrared photonic circuit, reaching wavelengths larger than 8 µm. Optical modulation in the wavelength range from 5.5 to 11 µm is shown, relying on a broadband Ge-rich graded-SiGe platform. This demonstration experimentally confirms the free-carrier absorption effect modeling. These results pave the way towards efficient high-performance electrically-driven integrated optical modulators in the mid-infrared wavelength range.