Optical waveguides – With optical coupler – Plural
Reexamination Certificate
1999-03-31
2001-10-16
Lee, John D. (Department: 2874)
Optical waveguides
With optical coupler
Plural
C385S015000, C385S053000, C385S134000
Reexamination Certificate
active
06304690
ABSTRACT:
TECHNICAL FIELD
This invention relates to apparatus for use in connecting a plurality of electrical circuit boards so each electrical circuit board can communicate with each other electrical circuit board.
BACKGROUND ART
Current switch fabrics employed in high bandwidth switches e.g. Asynchronous Transfer Mode switches and Synchronous Optical Networking Standards/Synchronous Digital Hierarchy SONET/SDH currently interconnect circuit boards via an electrical back plane. Where signals are required to be switched between circuit boards, an electrical switch fabric is also used, with all data paths routed via the back plane to the witch fabric. In order to increase the bandwidth of such systems, the capacity of the back planes and switch fabrics must be increased, with wider data paths and higher clock frequencies. Pin Counts, high clock frequencies and electromagnetic interference (EMI) make this problematic.
Optical back planes and switch fabrics offer the possibility of an architecture which is essentially independent of the bandwidth requirements placed upon it.
Such optical interconnects are discussed in the literature, e.g. BT Technol J Vol 9 No 4 1991, but all the work in this field has so far employed discrete optical components and the costs of fabricating prior art circuits has so far been prohibitive compared to the cost of the conventional electronic solution.
The present Invention aims to improve on this prior art and to provide optical apparatus for providing the required interconnection which is cost-effective when compared to the known electrical solutions.
DISCLOSURE OF INVENTION
According to the present invention, there is provided apparatus for use in connecting a plurality of electrical circuit boards so each electrical circuit board can communicate with each other electrical circuit board, the apparatus comprising an optical circuit for association with each electrical circuit board, each optical circuit comprising a transmitter module and a receiver module;
the transmitter module comprising:
a plurality of electrical to optical converter means for converting a plurality of electrical signals into a plurality of optical signals each of a different wavelength,
wavelength multiplexing means for multiplexing the optical signals of different wavelengths into a single optical waveguide, and
optical splitter means for dividing the multiplexed signal in the single optical waveguide into a plurality of identical signals for transmission to each of the receiver modules; and
the receiver module comprising:
optical selecting means for selecting signals from one or more of the transmission modules;
wavelength demultiplexing means for demultiplexing the selected signal or signals into a plurality of signals each of a different wavelength, and
a plurality of optical to electrical converter means for converting each of the said plurality of signals of different wavelengths into an electrical signal,
wherein the optical circuit comprises one or more integrated optical circuits providing:
wavelength multiplexing means comprising integrated directing means for directing the plurality of optical signals of different wavelengths into a single integrated optical waveguide;
optical splitter means comprising an integrated optical waveguide which successively divides into a plurality of integrated optical waveguides;
optical selecting means comprising a plurality of integrated optical input waveguides leading to a single integrated output waveguide;
wavelength demultiplexing means comprising an integrated transmission or reflection grating for directing signals of different wavelengths to respective optical to electronic converter means.
Preferred and optional features of the invention will be apparent from the following description and from the subsidiary claims of the specification.
REFERENCES:
patent: 3943021 (1976-03-01), Lindsey
patent: 4061577 (1977-12-01), Bell
patent: 4733093 (1988-03-01), Graves et al.
patent: 5155785 (1992-10-01), Holland et al.
patent: 5245680 (1993-09-01), Sauter
patent: 5355237 (1994-10-01), Lang et al.
patent: 5487120 (1996-01-01), Choy et al.
patent: 5612968 (1997-03-01), Zah
patent: 5793919 (1998-08-01), Payne et al.
patent: 6038355 (2000-03-01), Bishop
patent: 0 501 751 A1 (1992-02-01), None
patent: 0 593 287 A1 (1994-04-01), None
patent: 0 756 185 A2 (1997-01-01), None
patent: 0 758 799 A2 (1997-02-01), None
patent: 2 245 080 A (1991-12-01), None
patent: 2 315 595 A (1998-04-01), None
patent: 5-48074 A (1993-02-01), None
Bookham Technology plc
Fleshner & Kim LLP
Lee John D.
LandOfFree
Connecting a plurality of circuit boards does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Connecting a plurality of circuit boards, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Connecting a plurality of circuit boards will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2593238