Accession Number : ADP008632

Title :   Technique for Implementation of High-Speed Free-Space Optical Interconnections,

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Tsang, Dean Z.

Report Date : 22 MAY 1992

Pagination or Media Count : 4

Abstract : A free-space optical interconnection has zero insertion force and no ground planes. Low propagation delays are possible in board-to-board applications because of the direct path between interconnected points compared to the circuitous path often required by electrical interconnections. The optical channel has very high bandwidth and low dispersion. Furthermore, very high interconnection densities are possible because light beams can cross in free space. However, high-speed optoelectronic components are typically small and difficult to align in a computer environment. Experimental free-space optical interconnections have required the use of micropositioners for alignment and are not readily adapted for conventional computers. In this work, techniques for the practical implementation of high-speed board-to-board free-space optical interconnections without micropositioners have been developed. A free-space transmitter and receiver module combined with a card cage board enclosure designed for the application have made possible a differential electrical current efficiency (detector photocurrent divided by laser drive current) as high as 8%.

Descriptors :   *OPTICAL CIRCUITS, *CIRCUIT INTERCONNECTIONS, *COMPUTER APPLICATIONS, OPTICAL LENSES, CIRCUIT BOARDS, HIGH VELOCITY, COMPUTERS, OPTICAL DETECTORS, TRANSMITTERS, RECEIVERS, ALIGNMENT.

Subject Categories : Electrooptical and Optoelectronic Devices
      Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE