In 2016, we discovered that, to measure the spectrum of a stochastic signal on an optical interferometer (a task I shall call phase noise spectroscopy), photon counting is far superior to homodyne detection. We also found that photon counting is in fact the best measurement allowed by quantum mechanics for this task. Our paper: Shilin Ng, Shan Zheng Ang, Trevor … Continue reading Noise spectroscopy with an interferometer