Single-photon splitting by polymeric submicropillars structures

Optical splitters are one of the most important interconnects in the optical chips of future optical quantum computers. Here, we introduce novel quantum photonic splitters based on polymeric submicropillars that split the single-photon signal generated by a colloidal quantum dot (QD) into multiple outputs, which can be easily accessed through a conventional confocal scanning optical system. Using a single continuous-wave laser with a low absorption wavelength for both polymer material and QDs, we were able to first deterministically place a single-photon emitter (SPE) within one of the submicropillars and then characterize the single-photon guiding effect of the fabricated structures. The submicropillars, with their size and position which are comprehensively optimized by numerical simulations, act as single-mode directional coupler guiding both the laser excitation and the single-photon emission thanks to the evanescent wave coupling effect. With one-step fabrication, we can create a well-distributed array of “imaginary” SPEs from an original SPE. Our method opens various applications in integrated devices based on solid-state quantum emitters.