Phys.org February 12, 2024
An international team of researchers (Israel, Germany, USA- Los Alamos National Laboratory) demonstrated an important step toward on-chip integration of single-photon sources at room temperature. Excellent photon directionality was achieved with a hybrid metal–dielectric bullseye antenna, while back-excitation was permitted by placement of the emitter in a subwavelength hole positioned at its center. The design enabled a direct back-excitation and very efficient front coupling of emission either to a low numerical aperture (NA) optics or directly to an optical fiber. They fabricated devices containing either a colloidal quantum dot or a nanodiamond containing silicon-vacancy centers. Both back-excited devices displayed front collection efficiencies of ∼70% at NAs as low as 0.5. The combination of back-excitation with forward directionality enabled direct coupling of the emitted photons into a proximal optical fiber without any coupling optics facilitating and simplifying future integration… read more. TECHNICAL ARTICLE
Abstract. Credit: Nano Lett. 2024, 24, 2, 640–648, January 2, 2024