title: Ultrahigh-quality-factor silicon-on-insulator microring resonator.
abstract: The development of ultrahigh-quality-factor (Q) silicon-on-insulator (SOI) microring resonators based on silicon wire waveguides is presented. An analytical description is derived, illustrating that in addition to low propagation losses the critical coupling condition is essential for optimizing device characteristics. Propagation losses as low as 1.9 +/- 0.1 dB/cm in a curved waveguide with a bending radius of 20 microm and a Q factor as high as 139.000 +/- 6.000 are demonstrated. These are believed to be the highest values reported for a curved SOI waveguide device and for any directly structured semiconductor microring fabricated without additional melting-induced surface smoothing.
authors.affiliation: Institut für Halbleitertechnik, Rheinisch-Westfälische Technische Hochschule Aachen, Sommerfeldstrasse 24, 52056 Aachen, Germany. niehusmann@iht.rwth-aachen.de
authors.forename: Jan
authors.initials: J
authors.lastname: Niehusmann
authors.forename: Andreas
authors.initials: A
authors.lastname: Vörckel
authors.forename: Peter Haring
authors.initials: PH
authors.lastname: Bolivar
authors.forename: Thorsten
authors.initials: T
authors.lastname: Wahlbrink
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Henschel
authors.forename: Heinrich
authors.initials: H
authors.lastname: Kurz