Direct sunlight is often deemed incoherent, hence unsuitable for antenna power conversion. However, all radiation exhibits spatial coherence when detected on a sufficiently small scale. We report the first direct measurement of the spatial coherence of solar beam radiation, achieved with a customized tabletop cyclic-shearing interferometer. Good agreement is found between experiment and theory, with promising ramifications for solar aperture antennas.
© 2012 Optical Society of America
Coherence and Statistical Optics
Original Manuscript: June 25, 2012
Revised Manuscript: July 17, 2012
Manuscript Accepted: July 17, 2012
Published: August 20, 2012
Heylal Mashaal, Alex Goldstein, Daniel Feuermann, and Jeffrey M. Gordon, "First direct measurement of the spatial coherence of sunlight," Opt. Lett. 37, 3516-3518 (2012)