Experimental realization of deep sub-wavelength confinement of light in a topology-optimized InP nanocavity
Meng Xiong, Rasmus E. Christiansen, Frederik Schröder, Yi Yu, Laura Nevenka Casses, Elizaveta Semenova, Kresten Yvind, Nicolas Stenger, Ole Sigmund, Jesper Mørk
Abstract
We experimentally demonstrate an InP nanocavity with a mode volume of 0.26 ( λ /2 n ) 3 . This is an order of magnitude smaller than the mode volumes previously demonstrated in photonic crystal point-defect cavities realized in III-V materials and four times smaller than what is often referred to as the diffraction-limited volume, V λ = ( λ /2 n ) 3 . The nanocavity is designed using topology optimization, taking into account fabrication limitations, which are pushed compared to the state-of-the-art. This work thus introduces a new class of cavities featuring extreme dielectric confinement (EDC) into the realm of III-V semiconductors, offering order-of-magnitude Purcell-enhancement of the radiative rate. EDC nanocavities may thus be employed to significantly improve the properties of nanolasers, nanoLEDs and single-photon sources, among other applications.