Multichannel acousto-optic correlator for time delay computation

Claim 1

An in-line interferometric time integrating correlator comprising: (a) a first reference signal acousto-optic (AO) cell together with a first signal source for injecting a first reference signal therein at a first terminal portion thereof and propagating through said AO cell in a first direction; (b) a second AO cell together with a second signal source at a second terminal portion thereof, opposite said first terminal portion, for injecting a second signal therein, to be correlated with said first reference signal, and counter-propogating within said second AO cell with respect to the direction of propagation of said first reference signal; (c) a source of coherent light for directing a light beam along an optical axis and intersecting the first AO cell for producing an undiffracted beam emerging therefrom and a first plus one diffracted order beam exiting said first AO cell; (d) first imaging means for projecting the first plus one order diffracted beam from the first AO cell upon the second AO cell along with said undiffracted beam for producing second and third overlapping plus one diffracted order beams exiting said second AO cell; (e) a light integrating photodetector array means; (f) a second imaging means for imaging the second and third overlapping plus one diffracted order beams upon said photodetector array means, enabling the resulting interference to be integrated by said photodetector array means with respect to a user-defined integration time; and (g) Dove prism means, positioned within said first imaging means, in the path of said first plus one diffracted order beam, for causing the second and third plus one diffracted order beams to overlap upon exiting the second AO cell and scan in opposite directions at the photodetector array.