Single- and multi-photon imaging with a nanoscale detector

Study of subwavelength optical phenomena has taken an increasing importance in the past few years. Near- field scanning optical microscopy (NSOM) is the usual solution for optical sensing below the diffraction limit. It consists in coupling light in a fiber through a nanoscale hole and detecting it with a conventional detector. A better optimized method would be to make the detector itself nanoscale. The dark count rate being usually proportional to the active area, this would greatly enhance the signal to noise ratio. The paper proposed a detector that has nanoscale dimensions, nanosecond response time and single or multiphoton sensitivity.