Room-Temperature Fiber-Coupled Single-Photon Sources based on Colloidal Quantum Dots and SiV Centers in Back-Excited Nanoantennas
Boaz Lubotzky, Alexander Nazarov, Hamza Abudayyeh, Lukas Antoniuk, Niklas Lettner, V. Agafonov, Anastasia V. Bennett, Somak Majumder, Vigneshwaran Chandrasekaran, Eric G. Bowes, Han Htoon, Jennifer A. Hollingsworth, Alexander Kubanek, Ronen Rapaport
Abstract
We demonstrate an important step toward on-chip integration of single-photon sources at room temperature. Excellent photon directionality is achieved with a hybrid metal-dielectric bullseye antenna, while back-excitation is permitted by placement of the emitter in a subwavelength hole positioned at its center. The unique design enables 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. To show the versatility of the concept, we fabricate devices containing either a colloidal quantum dot or a nanodiamond containing silicon-vacancy centers, which are accurately positioned using two different nanopositioning methods. Both of these back-excited devices display front collection efficiencies of ∼70% at NAs as low as 0.5. The combination of back-excitation with forward directionality enables direct coupling of the emitted photons into a proximal optical fiber without any coupling optics, thereby facilitating and simplifying future integration.