Accession Number : ADA181856

Title :   Optical Carry Adder.

Descriptive Note : Final rept. Aug 85-Nov 86,

Corporate Author : AERODYNE RESEARCH INC BILLERICA MA

Personal Author(s) : McManus,J B ; Putnam,R S

PDF Url : ADA181856

Report Date : Mar 1987

Pagination or Media Count : 65

Abstract : We have constructed a hybrid electronic/electro-optic digital adder which uses an optical-carry for fully parallel operation. It adds two four-bit words at a data rate of 10 MHz. Electronic logic is used for summing the addend and carry bits, while the carries are generated optically. Ideally, this system reduces the number of gate delays associated with electronic addition of long addends, and has an execution time that does not increase with longer addends. The optical-carry (B. Arazi, Proc. IEEE 73, 162, 1/85) is based upon a multi-stage optical path, with sources which add light to the path if a carry is generated, and with modulators which allow light to pass if a carry is propagated, at the corresponding column of the addition. The signals which set the light sources and modulators are derived from the addends simultaneously, so the addition is completed as soon as detected light signals reach the summing logic. With small changes in the driving logic, the device operates as a parallel subtractor, with optical borrow propagation. Our breadboard system has six acousto-optic modulators (AOM's) as optical switches, with a single HeNe laser source. (Author)

Descriptors :   *ACOUSTOOPTICS, *LIGHT MODULATORS, *LOGIC, *ELECTRONICS, *LASERS, *PARALLEL PROCESSING, *SIGNAL LIGHTS, *OPTICAL SWITCHING, LIGHT SOURCES, MODULATORS, BREADBOARD MODELS, ELECTRONICS, TIME, LIGHT, PATHS, WORDS(LANGUAGE)

Subject Categories : Computer Hardware
      Acoustooptic and Optoacoustic Devices
      Electrooptical and Optoelectronic Devices
      Theoretical Mathematics
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE