Device and method for detecting the phase and amplitude of electromagnetic waves

An apparatus for detecting the phase and amplitude of electromagnetic waves, comprising at least two modulation photogates (1, 2) which are sensitive to the electromagnetic waves (photosensitive), and accumulation gates (4, 5) which are associated with the modulation photogates, said accumulation gates (4, 5) being not photosensitive, and electrical connections for the modulation photogates (1, 2) and the accumulation gates (4, 5), so that the latter can be connected to a reading-out device, and the former can be connected to a modulating device which increases or reduces the potential of the modulation photogates (1, 2) relative to each other and relative to a potential of the accumulation gates (4, 5) corresponding to a desired modulation function, characterized in that there are provided a plurality of modulation photogates (1, 2) and accumulation gates (4, 5) being formed of long narrow parallel strips which group-wise form a PMD-pixel, wherein the accumulation gates are reading-out diodes, wherein the accumulation gates of a (PMD-) pixel are divided into at least two groups of accumulation gates, each group being connected to a common readout line and means are provided for determining the difference of the signals received from the readout lines of the said at least two groups of accumulation gates.