Investigation of n -type gallium nitride grating for applications in coherent thermal sources

Abstract

In this study, polarized reflection and emission spectroscopy was employed in order to describe experimentally and numerically the coherent behavior of surface plasmon phonon polaritons in shallow n-type gallium nitride grating. For the grating with a 1 μm depth and an 11 μm period, polariton coherence was observed measuring the reduction of the linewidth and the redshift of the resonance position in both reflection and emission spectra with the increase in the incident angle. Maximum coherence conditions were found at a frequency of 562 cm-1 and an angle of 37°, demonstrating the coherence length value up to 724 μm (41λ).