title: Tunable negative group index in metamaterial structures with large form birefringence.
abstract: We experimentally verify the anomalous phase behavior in metamaterial structures with birefringent materials predicted by Mandatori, et. al. using form birefringent structures. Large birefringence as much as Deltan/n = 0.7 has been achieved by surface-treated form birefringent discs, making compact single layer Mandatori structures viable. With a reduced model of a single layer birefringent structure, the relationship between design parameters (thickness and orientation angle) and device operation and performance parameters (such as the center operation frequency, bandwidth, effective negative index, negative group index of refraction, and the transmission throughput) are derived and verified experimentally. Tunable group index of refraction from strong slow light of ng = 29.6 to fast light of ng = -1.1 are measured experimentally.
authors.affiliation: Department of Engineering and Technology, Western Carolina University, Cullowhee, NC 28723, USA.
authors.forename: Kirill
authors.initials: K
authors.lastname: Sinchuk
authors.forename: Richard
authors.initials: R
authors.lastname: Dudley
authors.forename: John D
authors.initials: JD
authors.lastname: Graham
authors.forename: Michael
authors.initials: M
authors.lastname: Clare
authors.forename: Mesfin
authors.initials: M
authors.lastname: Woldeyohannes
authors.forename: John O
authors.initials: JO
authors.lastname: Schenk
authors.forename: Robert P
authors.initials: RP
authors.lastname: Ingel
authors.forename: Weiguo
authors.initials: W
authors.lastname: Yang
authors.forename: Michael A
authors.initials: MA
authors.lastname: Fiddy
mesh_terms: D001718:Birefringence; D003198:Computer Simulation; D008027:Light; D008420:Manufactured Materials; D008422:Materials Testing; D008962:Models, Theoretical; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation