title: Low-loss germanium strip waveguides on silicon for the mid-infrared.
abstract: Mid-infrared photonics in silicon needs low-loss integrated waveguides. While monocrystalline germanium waveguides on silicon have been proposed, experimental realization has not been reported. Here we demonstrate a germanium strip waveguide on a silicon substrate. It is designed for single mode transmission of light in transverse magnetic (TM) polarization generated from quantum cascade lasers at a wavelength of 5.8 μm. The propagation losses were measured with the Fabry-Perot resonance method. The lowest achieved propagation loss is 2.5 dB/cm, while the bending loss is measured to be 0.12 dB for a 90° bend with a radius of 115 μm.
authors: Optics & Photonics Technology Laboratory, Ecole Polytechnique Fédérale de Lausanne, Breguet 2, 2000 Neuchâtel, Switzerland. yu‑chi.chang@epfl.ch
authors: Yu-Chi
authors: YC
authors: Chang
authors: Vincent
authors: V
authors: Paeder
authors: Lubos
authors: L
authors: Hvozdara
authors: Jean-Michel
authors: JM
authors: Hartmann
authors: Hans Peter
authors: HP
authors: Herzig