Nano Letters
Nanoscale Optical Detector with Single-Photon and Multiphoton Sensitivity
David Bitauld, Francesco Marsili, Alessandro Gaggero, F. Mattioli, Roberto Leoni, S. Jahanmiri Nejad, Francis Lévy, Andrea Fiore
Abstract
We present the first nanoscale (down to approximately 50 x 50 nm(2)) detector displaying single-photon sensitivity and a nanosecond response. This type of nanodetector can also be operated in multiphoton mode, where the detection threshold can be set at N = 1, 2, 3, or 4 photons, thus allowing the mapping of photon number statistics on the nanoscale. Its operation principle based on that of hot-spot formation in superconducting nanowires allies the temporal resolution and sensitivity of superconducting single-photon detectors with subwavelength resolution and photon number discrimination. Such detectors can be of great interest for the study of nanophotonic devices at low temperature.