Abstract: A multi-channel optical correlation system employs a light source to illuminate a mask having a plurality of linearly disposed channels, each of which has recorded information defined by variations in opacity along its linear length. The light source is modulated as a function of an unknown input signal. A multiple element charge coupled device having its elements arrayed in linearly disposed groups along axes parallel to the linearly disposed channels of the illuminated mask is positioned to receive the light energy transmitted by the illuminated mask for developing a charge within each such element commensurate with the photo energy received at its discrete position.

Abstract: Coextensive first and second optical waveguides are disposed with substantially uniform periodic variations in spatial separation including repetitive sections of close proximity which will permit optical coupling therebetween. The first optical waveguide has a different optical length (i.e., different light energy propagation characteristics) than the second optical waveguide. Due to the different effective optical lengths of the two waveguides between contiguous sections of close proximity where optical coupling may take place, light energy of a determinable frequency propagated along one of the waveguides is substantially all coupled into the other optical waveguide in the course of propagating along a determinable number of the repetitive sections; light energy of all other frequencies is effectively phase cancelled and thus inhibited from being coupled between the two optical waveguides.