Field of View Increase for Optical Heterodyne Receivers

The field of view of optical heterodyne systems are usually limited by a simple criterion- namely, that ARΩR ≍ λ2, where AR is an effective aperture, ΩR the corresponding field of view and λ the optical wavelength. This paper will demonstrate that with a simple change of systems geometry and the possible use of array detectors, this severe restriction can be alleviated considerably and, in some cases, eliminated. Both coherent sources and thermal radiation sources are considered. This might suggest that heterodyne systems that were eliminated in the past because of that criterion alone, could turn out to be, not only possible, but even advantageous compared to other techniques.