The Mach-Zehnder interferometer is shown in wikipedia and on David Harrison's page. If the second (upper right) half silvered mirror is taken away and no sample (as in the wikipedia setup) is in any of the two paths, I read that when sending individual photons through the device, roughly 50% of them end up in each detector. What I would like to know is the following: Does anyone know a paper where real counts are reported, e.g. like: "we send 100 individual photons, 49 ended up in 1 and 47 ended up in 2, 4 where lost"? If I further remove one of the detectors, what percentage of photons is registered in the remaining detector? (published counts available?) Thanks, Harald.