WP2: Metrology for commercial components for free-space QKD The aim of this work package is to establish measurement and characterisation facilities for components of free-space QKD devices. Within the scope of this project, we define the spectral range as that where silicon-based detectors are applicable, i.e. between 400 nm and 950 nm. Task 2.1: Measurement facilities for detectors for free-space QKD The aim of task 2.1 is to establish measurement facilities – using different methods – among the partners for single-photon detectors, their detection efficiencies (DE) and corresponding uncertainties relevant for free-space QKD (i.e. in the VIS-NIR). Task 2.2: Measurement facilities for sources used in free-space QKD The aim of task 2.2 is to establish measurement facilities among the partners for single-photon sources, and their corresponding measurands and uncertainties, relevant for open-space QKD. Task 2.3: Measurement facilities for components used in free-space QKD The aim of task 2.3 is to establish measurement facilities among the partners for components other than sources and detectors which are relevant for open-space QKD. The task focusses on polarization controllers with respect to the degree of polarization, intensity modulators with respect to modulation depth, attenuators with respect to transmission, and quantum random number generators. Task 2.4: Validation of facilities by measuring two key measurands (the detection efficiency of single-photon detectors and Glauber second-order auto-correlation function of a pseudo single-photon source) at a key vis/NIR wavelength (850 nm) The aim of task 2.4 is to validate the new measurement facilities by carrying out comparisons of selected measurands among the consortium. Task 2.5: Development of new few-photon detector and validation of measurement techniques for characterising components of free-space QKD systems The feasibility of using an induced-junction photodiode with predictable detection efficiency as an integrated primary standard for commercial QKD systems will be tested; efficient single-photon sources based on deterministic InGaAs quantum dot micro-lenses will be developed, optimised, and characterised with respect to their out-coupling efficiency and quantum optical features. A progress report on this Workpackage may be found on the Training page
