We suggest and demonstrate a tomographic method to fully characterize homodyne detectors at the quantum level. The operator measure associated with the detector is expanded in the quadrature basis and probed with a set of coherent states. The coefficients of the expansion are retrieved using a least squares algorithm. We then validate the reconstructed operator measure on nonclassical states. Finally, we exploit results to estimate the overall quantum efficiency of the detector.
@article{arxiv.1505.03297,
title = {Experimental quantum tomography of a homodyne detector},
author = {Samuele Grandi and Alessandro Zavatta and Marco Bellini and Matteo G. A. Paris},
journal= {arXiv preprint arXiv:1505.03297},
year = {2024}
}