title: Silicon-on-sapphire integrated waveguides for the mid-infrared.
abstract: Silicon waveguides are now widely used to guide radiation in the near-infrared, mainly in the wavelength range of 1.1 - 2.2 microm. While low-loss waveguides at longer wavelengths in silicon have been proposed, experimental realization has been elusive. Here we show that single-mode integrated silicon-on-sapphire waveguides can be used at mid-infrared wavelengths. We demonstrate waveguiding at 4.5 microm, or 2222.2 cm(-1), with losses of 4.3 +/- 0.6 dB/cm. This result represents the first practical integrated waveguide system for the mid-infrared in silicon, and enables a range of new applications.
authors.affiliation: Department of Electrical Engineering, University of Washington, Campus Box 352500, Seattle WA 98195-2500 USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Baehr-Jones
authors.forename: Alexander
authors.initials: A
authors.lastname: Spott
authors.forename: Rob
authors.initials: R
authors.lastname: Ilic
authors.forename: Andrew
authors.initials: A
authors.lastname: Spott
authors.forename: Boyan
authors.initials: B
authors.lastname: Penkov
authors.forename: William
authors.initials: W
authors.lastname: Asher
authors.forename: Michael
authors.initials: M
authors.lastname: Hochberg