title: Mid- to long-wavelength infrared plasmonic-photonics using heavily doped n-Ge/Ge and n-GeSn/GeSn heterostructures.
abstract: Heavily doped n-type Ge and GeSn are investigated as plasmonic conductors for integration with undoped dielectrics of Si, SiGe, Ge, and GeSn in order to create a foundry-based group IV plasmonics technology. N-type Ge1-xSnx with compositions of 0 ≤ x ≤ 0.115 are investigated utilizing effective-mass theory and Drude considerations. The plasma wavelengths, relaxation times, and complex permittivities are determined as functions of the free carrier concentration over the range of 10(10) to 10(21) cm-3. Basic plasmonic properties such as propagation loss and mode height are calculated and example numerical simulations are shown of a dielectric-conductor-dielectric ribbon waveguide structure are shown. Practical operation in the 2 to 20 μm wavelength range is predicted.
authors.affiliation: Department of Physics & Engineering Program, University of Massachusetts at Boston, 100 Morrissey Boulevard, Boston, Massachusetts 02125, USA. soref@rcn.com
authors.forename: Richard
authors.initials: R
authors.lastname: Soref
authors.forename: Joshua
authors.initials: J
authors.lastname: Hendrickson
authors.forename: Justin W
authors.initials: JW
authors.lastname: Cleary