Photon pairs bi-directionally emitted from a resonant metasurface
Changjin Son, Vitaliy Sultanov, Tomás Santiago‐Cruz, Aravind P. Anthur, Haizhong Zhang, Ramón Paniagua‐Domínguez, Leonid A. Krivitsky, Arseniy I. Kuznetsov, Maria V. Chekhova
Abstract
spontaneous parametric down conversion from a metasurface supporting a quasi-bound state in the continuum (BIC) leading to remarkable emission directivities. The pair generation rate is enhanced 67 times compared to the case of an unpatterned film of the same thickness and material. At the wavelength of the quasi-BIC resonance, photons are mostly emitted backwards, while their partners, spectrally detuned by only 8 nm, are emitted forwards. This behavior demonstrates fine spectral splitting of entangled photons and their bi-directional emission, never before observed in nanoscale sources. We expect this work to be a starting point for the efficient demultiplexing of photons in nanoscale quantum optics.