> it is essential that the photodetector output is directly proportional to the intensity (photon flux) of the input light From "Physicists use a 350-year-old

> it is essential that the photodetector output is directly proportional to the intensity (photon flux) of the input light From "Physicists use a 350-year-old theorem to reveal new properties of light waves" (2023) https://news.ycombinator.com/item?id=37226121#37226160 https://news.ycombinator.com/item?id=37226121#37226160 : >> "This means that hard-to-measure optical properties such as amplitudes, phases and correlations—perhaps even these of quantum wave systems—can be deduced from something a lot easier to measure: light intensity."