High refractive index in wurtzite GaP measured from Fabry-Perot resonances

摘要

We investigate the optical emission of wurtzite GaP/Al_(0.4)Ga_(0.6)P core/shell nanowires (NWs) transferred to a SiO_x substrate to demonstrate a high degree of waveguiding of the emitted photoluminescence (PL) signal. By analysing the Fabry-Perot mode spacing in combination with calculations of the guided modes in the NWs, we calculate a very high refractive index of bulk WZ GaP of 4.2 at a wavelength of 600 nm. The measured quality factors up to 600 indicate the excellent optical quality of the nanowire resonator.