Coexistence of air and dielectric modes in single nanocavity

A deterministic design method and experimental demonstration of single photonic crystal nanocavity supporting both air and dielectric modes in the mid-infrared wavelength region are reported here. The coexistence of both modes is realized by a proper design of photonic dispersion to confine air and dielectric bands simultaneously. By adding central mirrors to make the resonance modes be confined at the bandgap edges. high experimental Q-factors of 2.32 x 10(4) and 1.59 x 10(4) are achieved at the resonance wavelength of about 3.875 mu m and 3.728 mu m for fundamental dielectric and air modes. respectively. Moreover. multiple sets of air and dielectric modes can be realized by introducing central aperiodic mirrors with multiple bandgaps. The realization of coexistence of air and dielectric modes in single nanocavity will offer opportunities for multifunctional devices, paving the wav to integrated multi-parameter sensors, filters, nonlinear devices, and compact light sources. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement