title: Resonant light delay in GaN with ballistic and diffusive propagation.
abstract: We report on a strong delay in light propagation through bulk GaN, detected by time-of-flight spectroscopy. The delay increases resonantly as the photon energy approaches the energy of a neutral-donor bound exciton (BX), resulting in a velocity of light as low as 2100 km/s. In the close vicinity of the BX resonance, the transmitted light contains both ballistic and diffusive components. This phenomenon is quantitatively explained in terms of optical dispersion in a medium where resonant light scattering by the BX resonance takes place in addition to the polariton propagation.
authors: Ioffe Physico-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia.
authors: T V
authors: TV
authors: Shubina
authors: M M
authors: MM
authors: Glazov
authors: A A
authors: AA
authors: Toropov
authors: N A
authors: NA
authors: Gippius
authors: A
authors: A
authors: Vasson
authors: J
authors: J
authors: Leymarie
authors: A
authors: A
authors: Kavokin
authors: A
authors: A
authors: Usui
authors: J P
authors: JP
authors: Bergman
authors: G
authors: G
authors: Pozina
authors: B
authors: B
authors: Monemar