Optical mesh-connected bus interconnect for a computer

• US 5,465,379 A
• Filed: 03/01/1994
• Issued: 11/07/1995
• Est. Priority Date: 03/19/1992
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Research Institute, Inc. (NEC Corporation)
• Inventors: Rao, Satish, Li, Yao
• Primary Examiner(s): Lim, Krisna
• Application Number:
  US08/204,765
• Time in Patent Office: 616 Days
• Field of Search: 395/800, 350/96.24, 385/7, 385/17, 385/4, 385/15, 385/31, 385/33, 385/47, 385/53, 385/119, 385/39
• US Class Current: 712/11
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H04Q 11/0062 Network aspects
• CPC Class Codes: H04Q 2011/0007 Construction
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• 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 2011/0052 Interconnection of switches

Abstract

Different components of a computer are interconnected by a free space optical mesh-connected bus network using wavelength division multiple access. The network includes optical elements, such as cylindrical lens or mirrors, to transform a spot of light emitted by a source into a stripe of light that illuminates a row or column of detectors, of which one is tuned to the wavelength of the light for selection. By a succession of such networks appropriately oriented, routing in different perpendicular directions through the network is achieved, whereby any two nodes in a two-dimensional array of nodes can be interconnected.

Claims

1. A mesh-connected bus network comprising:

a plurality of processing modules, each processing module including a processing element, a first and a second light source means, and a first and a second light detecting means, the first and second light source means of said processing modules forming, respectively, first and second two-dimensional arrays of rows and columns of light source means, the first and second light detecting means of the modules forming, respectively, first and second two-dimensional arrays of columns and rows of light detecting means, the first two-dimensional array of light source means being associated with the first two-dimensional array of light detecting means, and the second two-dimensional array of light source means being associated with the first two-dimensional array of light detecting means, the first array of light source means and the first array of light detecting means forming a first routing stage, the second array of light source means and the second array of light detecting means forming a second routing stage orthogonal to said first routing stage,

means for optically routing signals in the first stage of said network comprising means for converting a spot of light emitted by any one of said light sources means of any row of said first two-dimensional arrays of light source means into a stripe of light and directing said stripe of light over each of the detecting means in the associated row of the first two-dimensional array of light detecting means, and

means for optically routing signals in the second stage of the network comprising means for converting a spot of light emitted by any one of said light source means in any column of said second two-dimensional array of light source means into a stripe of light and directing said stripe of light over each of the detecting means in the associated column of the second two-dimensional array of light detecting means.

2. The network of claim 1 in which the separate pairs of light sources and light detectors are supported on opposite surfaces of a support member with the light sources and light detectors that are members of the same processing module being proximate one another on said support member.

3. The network of claim 1 in which the optical means for converting the spot of light emitted from a light source first and second comprises combinations of a cylindrical lens and a right angle roof-top reflector, said cylindrical lenses and said reflectors in the separate combinations being orthogonally oriented.

4. The network of claim 1 in which the optical means for converting the spot of light from a light source into a stripe comprises separate cylindrical mirrors, the curvature of the separate mirrors being oriented orthogonally.

5. The combination of claim 1 in which the wavelength of the light emitted by the light source means is different for each light source means in a given row and in a given column and the light detecting means are tunable selectively to respond to each of the different wavelengths of the light sources.

6. The network of claim 1 in which each of said optical means is the combination of a cylindrical lens and a right-angle roof reflector, and the orientation of the cylindrical lens and the roof reflector varies by about 90 degrees in the two optical means.

7. The optical interconnect network of claim 1 in which each of said optical means is a curved cylindrical mirror and the orientations of the mirrors in the two optical means are orthogonal.

8. A network in accordance with claim 1 in which the processing elements and the arrays of light source means and light detecting means lie essentially on a common plane, and the optical routing means lie on planes spaced from said common plane to provide free space for the routing.

9. An optical interconnect network for interconnecting a number of processing elements comprising:

a planar support member,

a first and a second two-dimensional array in rows and columns of light sources and light detectors on each of the opposed surfaces of the planar support member,

the light detectors on one side of the support member being coupled to the light sources on the other side of the support member, the first and second two-dimensional arrays providing orthogonal first and second routing stages,

a pair of optical means, separate ones spaced on opposite sides of the support member, one for converting a spot of light emitted from a light source in the first array of light sources into a stripe of light incident on each of the light detectors in a single row of the first array of light detectors, the other for converting a spot of light emitted from a light source in the second array of light sources into a stripe of light incident on each of light detectors in a single column of the second array of light detectors.

10. A network for providing free space optical routing comprising:

a plurality m×

n of means for emitting a spot of light arranged in a first two-dimensional array of m rows and n columns, each of said means in a row emitting light of a different wavelength, each of the means in a column emitting light of a different wavelength,

a plurality of m×

n means for detecting light arranged in a second two-dimensional array of rows and columns corresponding to said first two-dimensional array, each of said second means being tunable to detect a particular one of m wavelengths, and

optical means positioned between the light emitting means and the light detecting means for converting the m×

n spots of light into n stripes of light, each stripe of light irradiating selectively a different column of light detecting means.

11. A network in accordance with claim 10 in which each row and each column of the array of emitting means have N emitting means and each row and each column of the detecting means have N detecting means.