Plane wave imager with synthetic aperture capability

A two-dimensional plane wave imager (PWI) comprising an array of light collections sites (LCS), the PWI comprising:

• each LCS comprising a coupler of scene light into an interferometer further comprising a first and a second output arm;
• the first and second output arms each split into two branch arms, thereby comprising first and second branch arms split from the first output arm, and third and fourth branch arms split from the second output arm;
• the first branch arm connected to a first spectral filter, and the fourth branch arm connected to a second spectral filter, each of the first and second spectral filters producing as an output two identical light spectra;
• an output of the first spectral filter, the second branch arm, the third branch arm, and an output of the second spectral filter each connected to a respective first, second, third and fourth photo diode, such that light spectra impinge each one of four photo diodes, and such that the first and second photo diodes sense interferometer outputs of the first output arm and third and fourth photo diodes sense interferometer outputs of the second output arm, in two light spectrum bands;
• control circuitry operative with the interferometer, to control the light in the first and second interferometer output arms to a zero delay condition for the light in either light spectrum or for a sum of the light spectra;
• sensing circuitry responsive to output signals from each of the first, second, third, and fourth photodiodes:
• to determine first output signal differences between spectral bands on an output of the first spectral filter and on an output of the second branch arm;
• or
• to determine second output signal differences between spectral bands on an output of the third branch arm and an output of the second spectral filter;
• or
• wherein a first sum comprises the output of the first spectral filter and the output of the second branch arm and a second sum comprises the out of the third branch arm and the output of the second spectral filter, to determine third output signal differences between the first and second sums;
• and
• the first, second, or third signal differences operative as (real, imaginary) inputs to a Fourier Transform component, wherein the Fourier Transforms represent an image of the scene.