Quantum Radiometric Calibration

Abstract

Optical quantum computing, as well as sensing technology based on quantum correlations are in preparation. These require photodiodes with close to perfect quantum efficiency for the detection of about 10^16 to 10^18 photons per second. Already the radiometric calibration is a challenge. Here, we provide the proof of concept of the quantum radiometric calibration (QRC) method, which is based on Heisenberg's uncertainty principle, derive the formula for its precision, and exclude the potential sources of systematic error. As an example, we calibrate a pair of the most efficient commercial photodiode at 1550 nm to the previously unknown system detection efficiency of (97.20 +/- 0.37)% using 10-dB-squeezed vacuum states. This value is unexpectedly low, too low for planned gravitational wave detectors and for continuous-variable optical quantum computing. With further improved precision, our work opens up the second true end-user application of the advantage provided by quantum correlations.