Investigation of spatial coherence of hybrid surface plasmon-phonon-polaritons in n-GaN gratings

Record high spatial coherence values up to 87λ (130λ) in experiment (theory) were reported for polarized emission of surface plasmon-phonon polaritons excited in shallow surface relief n-GaN grating. Unusual independence of quality factor and dependence of spatial coherence length on the grating wavevector were observed in the course of a thorough investigation of dispersion characteristics of these quasiparticles.