Williams R E, Bieren K, Morales M
Appl Opt. 1975 Dec 1;14(12):2944-54. doi: 10.1364/AO.14.002944.
A wide-aperture optical correlator-spectrum analyzer has been developed that achieves its full theoretical maximum processing gain of 36 dB. This 4000-channel system is coherent across the 100-mm-diam aperture with 100-lines/mm resolution at the center. The system noise is not perceptible, and the time-bandwidth product is 9000. Performance tests are described and evaluated for aperture coherence, Fourier transform accuracy and resolution, and processing gain.