Apparatus having a plurality of photodetectors interconnected to form an electrical circuit corresponding to any given logic function comprising at least two of the four basic AND, OR, NAND, and NOR logic operations. The apparatus performs optical logic without optical cascading since the electrical circuit controls the generation of an optical output beam based on the value that the given logic function assumes in response to a plurality of optical signal beams each incident on at least one of the photodetectors. A complementary optical output is obtained and time-sequential operation is effected when two, serially connected quantum well p-i-n diodes comprising an S-SEED are used to generate optical output beams in response to the voltage developed by the electrical circuit of interconnected photodetectors.