Design centering of a GaN photonic crystal nanobeam

It is well known that structures containing photonic crystal cavities produce cavity modes with extremely large Q-factors. This type of structure can be hyper sensitive to both design and manufacturing processes. Each parameter, be it structural or material will have a tolerance associated with it and the purpose of design centering is to obtain a final design that will achieve the highest yield while maintaining, not the maximum cavity Q factor available, but a value close to it. In this paper, we show how the cavity Q-factor of a photonic crystal nanobeam varies with some structural parameters using both two and three dimensional Lumerical FDTD s1.