title: Encapsulated subwavelength grating as a quasi-monolithic resonant reflector.
abstract: For a variety of laser interferometric experiments, the thermal noise of high-reflectivity multilayer dielectric coatings limits the measurement sensitivity. Recently, monolithic high-reflection waveguide mirrors with nanostructured surfaces have been proposed to reduce the thermal noise in interferometric measurements. Drawbacks of this approach are a highly complicated fabrication process and the high susceptibility of the nanostructured surfaces to damage and pollution. Here, we propose and demonstrate a novel quasi-monolithic resonant surface reflector that also avoids the thick dielectric stack of conventional mirrors but has a flat and robust surface. Our reflector is an encapsulated subwavelength grating that is based on silicon. We measured a high reflectivity of 93% for a wavelength of lambda = 1.55 microm under normal incidence. Perfect reflectivities are possible in theory.
authors.affiliation: Institut für Angewandte Physik, Friedrich-Schiller-Universität Jena, Max-Wien-Platz 1, 07743 Jena, Germany. roman.schnabel@aei.mpg.de
authors.forename: Frank
authors.initials: F
authors.lastname: Brückner
authors.forename: Daniel
authors.initials: D
authors.lastname: Friedrich
authors.forename: Michael
authors.initials: M
authors.lastname: Britzger
authors.forename: Tina
authors.initials: T
authors.lastname: Clausnitzer
authors.forename: Oliver
authors.initials: O
authors.lastname: Burmeister
authors.forename: Ernst-Bernhard
authors.initials: EB
authors.lastname: Kley
authors.forename: Karsten
authors.initials: K
authors.lastname: Danzmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Tünnermann
authors.forename: Roman
authors.initials: R
authors.lastname: Schnabel
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007909:Lenses; D008027:Light; D012031:Refractometry / Q000295:instrumentation*; D012542:Scattering, Radiation