Experimental Verification of Degenerate Band Edge Dispersion in Silicon Photonic Integrated Circuits

On resonance, periodic dielectric media of finite length exhibit large and distributed internal electric field distributions. The large and distributed fields have been exploited for applications in light emission, optical switching, and nonlinear optics. Resonance quality factors scale as the number of periods cubed near a regular band edge with quadratic dispersion. For chip-scale integrated photonics, significant footprint reduction is possible by exploiting the quartic dispersion of a degenerate band edge with quality factors that scale to the fifth power of the number of periods. Band diagrams with quartic dispersion are extracted from transmission measurements of fabricated devices realized in silicon photonics. Transmission measurements show Fano resonances with a sharp transmission peak-to-bandgap extinction ratio of 20 dB and quality factors of 27 000.