Investigation of the reflectivity spectra of n-type GaN semiconductor with surface relief grating

Reflectivity spectra of n-type GaN with a shallow or deep relief gratings were investigated theoretically and experimentally in the frequency range of 100-1500 cm^-1. The surface Phonon-Plasmon-Polariton modes for the strong field confinement within GaN micro-cavities were engineered by proper selection of the periodicity, filling factor, and depth of the groves. Application of such surface relief gratings is important for the development of total power absorbers, filters, waveguides, and other types of optoelectronic devices.