Nanoscale single- and multi-photon mapping of optical fields

TL;DR

This paper introduces a novel nanoscale detector capable of single- and multi-photon detection with high spatial and temporal resolution, enabling detailed mapping of optical fields at the nanoscale for advanced photonic applications.

Contribution

The development of the first nanoscale detector (~50x50 nm²) with single-photon sensitivity, nanosecond response, and multi-photon operation for near-field optical mapping.

Findings

Detector exhibits single-photon sensitivity.

Operates in multi-photon mode with adjustable thresholds.

Enables high-resolution mapping of optical fields.

Abstract

The study of optical phenomena on the subwavelength scale is becoming increasingly important in photonics, particularly in the fields of nanoemitters, photonic crystals and plasmonics. Subwavelength field patterns are evanescent and must thus be investigated with near-field techniques. The light powers emitted by nanoscale sources are extremely low, undermining the traditional approach of scattering a near field to a large (thus noisy) far-field detector. Nanoscale detectors, providing direct sensing in the near-field with small noise due to a small active area, are needed in high-sensitivity, high-resolution near-field imaging and in quantum nanophotonic circuits. Here we report the first nanoscale ~50x50nm2) detector displaying single-photon sensitivity and a nanosecond response. These nanodetectors can also be operated in multi-photon 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.