Full optical confinement in 1D mesoscopic photonic crystal-based microcavities: an experimental demonstration

Full light confinement in mesoscopic photonic crystal membranes, forming a mesoscopic self-collimating 1D Fabry-Pérot cavity, was predicted by Magno et al. [Opt. Lett. 39(14), 4223-4226 (2014)], using 2D calculations. Mesoscopic self-collimating cavities enable full light confinement despite the lack of index- or bandgap-guiding along one direction due to the flatness of the cavity reflectors. In this paper, we study these cavities using 3D-FDTD modelling and demonstrate that 3D light confinement survives the high losses inherent to the out-of-plane diffraction. Furthermore, we report an experimental demonstration at telecom wavelength on GaAs membranes with Q factors above 1700. This structure may pave the way for the fabrication of innovative configurations devoted to biochemical sensing and optical tweezing for nanoparticle manipulation thanks to its translational invariance property.