Within the scope of European research projects, PTB is characterizing single-photon sources based on InGaAs quantum dots. A measuring facility that allows the micro-photoluminescence spectroscopy of quantum dots in the near infrared range at temperatures of up to 4 K by means of a confocal microscope is available for this purpose.
Single-photon sources based on semiconducting quantum dots are particularly interesting for metrology due to their narrow-band emission, among other things. They can be combined with the determination of the absolute photon flux to realize defined powers. The objective of this work consists in developing absolute radiation standard sources, e.g. to calibrate single-photon detectors efficiently in optical quantum technology and possibly to realize the candela, the SI base unit of luminous intensity, based on quantum metrology.
[ more ]