"ROCHESTER UNIV N Y Dept. of PHYSICS AND ASTRONOMY." . . "Phototubes." . . "Optical detectors." . . "Bandwidth." . . "Coherent radiation." . . "Optical Detection and Detectors." . . "Demodulation." . . "Heterodyning." . . "Optical communications." . . . . . . . . "Coherence Effects in the Detection of Weak Light Signals"@en . . . . . . "This final report describes research carried out on the problem of detecting a weak light beam by the heterodyne method, and on the phase retrieval problem. It has been shown that Siegman's antenna theorem does not provide the principal limitation on the detectability of a weak light signal, and that, in general, there exists an optimum detector size that depends on the orientation of the detector. On the basis of this conclusion, it is suggested that a search for an unknown light signal be conducted with a detector of variable aperture. With the help of certain analytic properties of optical wave functions, it has been shown that the phase distribution of an optical image can be derived from measurements of the light intensity distribution."@en . . . . . . "Non-radio Communications." . . . . "Signal to noise ratio." . . "Optics." . .