Coherent light phase detecting focal plane charge-transfer-device

A coherent light phase detecting focal plane array uses a bulk substrate of a first conductivity-type semiconductor, with a layer of the opposite conductivity-type of that semiconductor formed into an array of CTD cells each storing charge converted from optical photons impingent upon the layer, when positioned in the focal plane of apparatus in which the array is used. Surrounding each cell are four FET structures which separately and individually collect the charge samples during an associated different one of four sampling periods, corresponding to the four quadrants of a two-dimension phase space (+I, +Q, -I and -Q samples). Each FET has five gate electrodes, so as to provide five individual regions for storage and manipulation of the photo-induced change during acquisition, readout and disposal. A correlated-double-sampling form of readout provides separate in-phase I axis video information and quadrature-phase Q axis video information, from which a determination of the amplitude and phase of the light impingent upon each pixel can be made.