Abstract: A technique for performing multiplication oriented optical digital computations in which a pair of identical primary frequency coherent beams of light are directed off-axis through a second harmonic generating crystal to produce an on-axis frequency doubled (i.e. second harmonic) output signal. Each primary beam is encoded with one of the quantities to be multiplied producing an output beam containing the product of the two quantities. The output beam is detected by an array type detector. The technique can be used in performing time integration applications as well as spatial integration applications. For space integration applications a cylindrical lens is positioned in front of the array detector. Multistage operations are realized using a parameteric frequency down conversion and amplification scheme.