Transmission behaviors of single mode hollow metallic waveguides dedicated to mid-infrared nulling interferometry.
This paper reports the characterization of hollow metallic waveguides (HMW) to be used as single-mode wavefront filters for nulling interferometry in the 6-20microm range. The measurements presented here were performed using both single-mode and multimode conductive waveguides at 10.6microm. We found propagation losses of about 16dB/mm, which are mainly due to the theoretical skin effect absorption in addition to the roughness of the waveguide's metallic walls. The input and output coupling efficiency of our samples has been improved by adding tapers to minimize the impedance mismatch. A proper distinction between propagation losses and coupling losses is presented. Despite their elevate propagation losses, HMW show excellent spatial filtering capabilities in a spectral range where photonics technologies are only emerging.
Abel-Tibérini
Laëtitia
L
Laboratoire d'Astrophysique Observatoire de Grenoble, BP53, F-38041 Grenoble Cedex 9, France. laetitia.abel@fresnel.fr
Labadie
Lucas
L
Arezki
Brahim
B
Kern
Pierre
P
Grille
Romain
R
Labeye
Pierre
P
Broquin
Jean-Emmanuel
JE
D007259:Infrared Rays; D007368:Interferometry / Q000379:methods*; D008027:Light; D008670:Metals / Q000737:chemistry*; D016062:Porosity; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation
D008670:Metals