Multidimensional switching networks

• US 5,953,143 A
• Filed: 12/06/1995
• Issued: 09/14/1999
• Est. Priority Date: 04/30/1993
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Research Institute, Inc. (NEC Corporation)
• Inventors: Sharony, Jacob, Li, Yao
• Primary Examiner(s): BACARES, RAFAEL D
• Application Number:
  US08/574,462
• Time in Patent Office: 1,378 Days
• Field of Search: 359/128, 359/117, 359/125, 359/126, 359/137, 359/139, 359/123
• US Class Current: 398/46
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0018 using tunable transmitters or receivers
• CPC Class Codes: H04Q 2011/0022 using fibre gratings
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast

Abstract

A switching network that utilizes at least three degrees of freedom, time, wavelength and space. In one embodiment that involves point-to-point switching, each space channel between an input and an output is assigned a time slot and wavelength coordinate characteristic of the output and the input transmitter and output receiver are tuned to the appropriate time and wavelength coordinates and selective switching is used to complete the space channel between the input and output. In another embodiment for generalized switching, each input channel is assigned a set of space, time slot and wavelength coordinates and an input signal is broadcast to all of the outputs which selectively makes connection to those inputs with an appropriate set of coordinates.

Claims

1. A transmission system capable of interconnecting each input of an nxn two dimensional array of light source inputs to any one or more outputs of an nxn two dimensional array of output comprising:

an nxm array of input sources of light beams;

an nxn array of output receivers of light beams;

means for forming the light beam of each input source into an nxn array of light beams, each having a different direction;

means for collecting the arrays of light beams from all the input sources and focusing them at their crossovers into an nxm array of spots, each spot representing the convergence of nxn beams;

means for deflecting the light beams associated with said spots in one of two orthogonal directions and selecting from each spot n beams to provide a total of n² ×

n light beams;

means for deflecting said n×

n² light beams in the other of the two orthogonal directions and selecting therefrom an array of nxn lights beams; and

means for focusing the selected array of light beams on said nxm array of output receivers.

2. A generalized transmission system for interconnecting each input of and nxm two dimensional array of inputs to any one or more outputs of an nxm two dimensional array of outputs, the transmission system comprising:

an nxm array of input sources of light beams;

an nxm array of output receivers of light beams;

means for forming the beam of each input source into an nxm array of divided light beams, each having a different direction; and

means for selecting on the basis of direction from each of said nxm arrays of divide light beams light beams destined for the output receivers to which the input source of said selected divided light beams was to be connected.

3. The generalized transmission system of claim 2 in which the light beam from an input source that is to be connected to an output source is passed through a two dimensional grating means for forming therefrom a two dimensional mxn array of light beams, each having a different direction and the array of light beams is passed through deflecting means, aperture means, and focusing means for selecting on the basis of direction the light beams for the output receivers associated with the outputs to be interconnected.

4. The transmission system of claim 2 in which said different directions are in free space.

5. The transmission system of claim 3 in which said different directions are in free space.

6. The transmission system of claim 2 in which the light beam from each input source is passed through a separate lenslet for collimation and then passed through a common two-dimensional grating for converting the beam into an array of nxn angularly multiplexed beams, and further comprising means for selecting from the nxn array of light beams associated with each input source a single light beam for incidence on a selected output receiver of the array of output receivers.