Patents by Inventor Michael M. Choy

Michael M. Choy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Optical wavelength division multiplexer for coupling to data sources and sinks, wherein at least two data sources and sinks operate with different communication protocols
    Patent number: 5825949
    Abstract: A wavelength division multiplexer (WDM) unit (12) includes a plurality of Input/Output cards (IOCs 14). Each IOC is bidirectionally coupled to I/O specific media (fiber or copper) and to two coaxial cables. Also bidirectionally coupled to the coaxial cables are a plurality of Laser/Receiver Cards (LRC 20). The interface between the IOCs and the LRCs is an Emitter Coupled Logic (ECL) electrical interface that is conveyed over the coaxial cables. Each LRC is bidirectionally coupled by two single mode fibers to an optical multiplexer and demultiplexer, embodied within a grating (24). An input/output port of the grating is coupled to a fiber link (28) that enables bidirectional, full duplex data communications with a second WDM. Each WDM also includes a Diagnostic Processor Card (DPC 28) that receives status signals from the IOCs and LRCs, that forwards the status signals on to an external processor, and which generates control information for the IOCs and LRCs.
    Type: Grant
    Filed: April 3, 1997
    Date of Patent: October 20, 1998
    Assignee: International Business Machines Corporation
    Inventors: Michael M. Choy, Paul Eliot Green, Jr., William Eric Hall, Frank James Janniello, Jeff Kenneth Kravitz, Karen Liu, Rajiv Ramaswami, Franklin Fuk-Kay Tong
  • Optical wavelength division multiplexer for high speed, protocol-independent serial data sources
    Patent number: 5487120
    Abstract: A wavelength division multiplexer (WDM) unit (12) includes a plurality of Input/Output cards (IOCs 14). Each IOC is bidirectionally coupled to I/O specific media (fiber or copper) and to two coaxial cables. Also bidirectionally coupled to the coaxial cables are a plurality of Laser/Receiver Cards (LRC 20). The interface between the IOCs and the LRCs is an Emitter Coupled Logic (ECL) electrical interface that is conveyed over the coaxial cables. Each LRC is bidirectionally coupled by two single mode fibers to an optical multiplexer and demultiplexer, embodied within a grating (24). An input/output port of the grating is coupled to a fiber link (28) that enables bidirectional, full duplex data communications with a second WDM. Each WDM also includes a Diagnostic Processor Card (DPC 28) that receives status signals from the IOCs and LRCs, that forwards the status signals on to an external processor, and which generates control information for the IOCs and LRCs.
    Type: Grant
    Filed: February 9, 1994
    Date of Patent: January 23, 1996
    Assignee: International Business Machines Corporation
    Inventors: Michael M. Choy, Paul E. Green, Jr., William E. Hall, Frank J. Janniello, Jeff K. Kravitz, Karen Liu, Rajiv Ramaswami, Franklin F. Tong
  • Wavelength division multiplexing using a tunable acousto-optic filter
    Patent number: 5173794
    Abstract: A fiber-optic communication system in which two or more lasers of different wavelengths are modulated with respective data signals. The laser outputs are coupled to a common optical fiber. A receiving station receives all the signals on the optical fiber. A tunable acousto-optical filter in the receiving station is electrically tuned to the laser frequency carrying the desired data signal and passes only the optical signal with that frequency to an optical detector.
    Type: Grant
    Filed: March 16, 1989
    Date of Patent: December 22, 1992
    Assignee: Bell Communications Research, Inc.
    Inventors: Kwok-Wai Cheung, Michael M. Choy