High quality factor nanocavity in a rod-type photonic crystal structure for controlling TM light

In this study, we propose a high quality (Q) factor nanocavity in a rod-type photonic crystal slab structure for controlling TM light. By analyzing the dispersion relations of the rod-type photonic crystal waveguides, we design a heterostructure nanocavity consisting of many waveguides with different lattice constants. The Q factor of the nanocavity is as high as 470,000, and its modal volume is as small as 0.7(λ/n)3. Furthermore, we investigate the influence of asymmetrically and symmetrically low-index-clad structures on the Q factor of the cavity.