Figure 3.

(a) Experimental (red dash line), transfer matrix method (blue solid line), and finite element method simulated (black solid line) reflectance spectra from the GaN/MP-GaN DBR structure. The reflectance spectra of the unetched sample (green solid line) and the sapphire substrate (orange solid line) are also shown for comparison. (b) Electric field distribution in a GaN/MP-GaN DBR with real pore morphology inputted by digitising the SEM image shown in Fig. 2b into the finite element model. (c) Photograph of an as-etched 2-inch mesoporous GaN DBR wafer reflecting a card with the Cambridge University Logo.