Spatially antibunched semiconductor laser beam for sub-shot-noise-limited apertured transmission

It is shown that, using a semiconductor laser, one can generate spatially antibunched light. This light displays a smaller variance when measured over finite spatial regions than light from a classical source. In analogy with the common (temporal) amplitude-squeezed light, which possess photon statistics that are more regularly spaced in time than a Poissonian, this spatially amplitude-squeezed light produces a beam having photon statistics that are more highly correlated across its transverse extent than the typical (having Poissonian detection statistics) laser beam. One may have a spatially amplitude-squeezed source which does not display temporal squeezing, and one may have a temporally amplitude-squeezed source which does not display spatial amplitude squeezing. The possibility of having both forms of amplitude squeezing simultaneously is considered and such a device, using semiconductor laser technology, is proposed. Analysis reveals that there is indeed a quantum correlation between different segments of the beam. This spatially antibunched light suffers less signal-to-noise degradation when spatially partitioned in the object or subsequent image planes, making it potentially superior in spatial light modulation, free-space transmission, or imaging applications.