One-to-many simultaneous and reconfigurable optical two-dimensional plane interconnections using multiple wavelength, vertical cavity, surface-emitting lasers and wavelength-dependent detector planes

• US 5,546,209 A
• Filed: 03/11/1994
• Issued: 08/13/1996
• Est. Priority Date: 03/11/1994
• Status: Expired due to Fees

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.), University of Southern California
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.), University of Southern California
• Inventors: Leight, James E., Willner, Alan E., Chang-Hasnain, Constance J.
• Primary Examiner(s): Boudreau, Leo
• Assistant Examiner(s): MEHTA, BHAVESH M
• Application Number:
  US08/209,866
• Time in Patent Office: 886 Days
• Field of Search: 359/117, 359/139, 359/128, 359/66, 359/885, 359/68, 359/890, 359/891, 359/618, 359/634, 359/124, 359/114, 359/115, 372/45, 372/50, 250/551
• US Class Current: 398/43
• CPC Class Codes: G02B 6/43 Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: H04Q 11/0003 Details
• CPC Class Codes: H04Q 2011/0007 Construction
• CPC Class Codes: H04Q 2011/0009 using wavelength filters
• CPC Class Codes: H04Q 2011/0013 using gating amplifiers
• CPC Class Codes: H04Q 2011/0018 using tunable transmitters or receivers
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0047 Broadcast; Multicast
• CPC Class Codes: H04Q 2011/0052 Interconnection of switches

Abstract

Optical communication apparatus for simultaneously and reconfigurably establishing optical communication channels, comprises at least one light source and a plurality of wavelength-selective detectors optically associated with each light source, the detectors arranged one behind another. The apparatus uses wavelength-division-multiplexing (WDM) to facilitate simultaneous and reconfigurable communication of one-to-many 2-D optical planes. This advance dramatically increases the system functionality of optical-plane interconnects. Such a system is realized by incorporating several multiple wavelength vertical-cavity surface-emitting lasers (VCSEL) into each transmitting pixel and incorporating wavelength selectivity into each subsequent detecting plane which will absorb one wavelength and be transparent to the rest; these structures can be fabricated by slightly modifying existing technology. This system allows for increased processing functionality of communicating both simultaneously and reconfigurably between many planes; broadcasting and dynamic independent interconnects are thus enabled.

Claims

1. Optical communication apparatus for simultaneously and reconfigurably establishing optical communication channels, comprising a plurality of light sources and a plurality of wavelength-selective detectors optically associated with said plurality light sources, wherein each of said light sources emits at a different wavelength and each of said wavelength-selective detectors has a different spectral response, said plurality of wavelength-selective detectors arranged one behind another such that each subsequent wavelength-selective detector will absorb and detect the shortest wavelength and be transparent to other longer wavelengths.

2. The optical communication apparatus of claim 1 comprising a plurality of pixels, each pixel including an identical source array, each array comprising a plurality of said light sources, each light source operating at a different wavelength, and each array optically associated with a said plurality of wavelength-selective detectors.

3. The optical communication apparatus of claim 2 comprising:

(a) at least one two-dimensional transmitting plane, each transmitting plane provided with a plurality of pixels, each pixel comprising a said identical source array; and

(b) at least two two-dimensional detector planes, each detector plane behind another and all detector planes behind said at least one transmitting plane, each detector plane provided with a plurality of said wavelength-selective detectors, each detector on each of said two-dimensional detector planes associated with a given pixel on a previous said two-dimensional transmitting plane and having a cut-off in wavelength detection that increases in wavelength for detector planes further away from said transmitting plane.

4. The optical communication apparatus of claim 3 comprising a single said two-dimensional transmitting plane and at least two said two-dimensional detector planes.

5. The optical communication apparatus of claim 3 comprising a first said two-dimensional transmitting plane, a last said two-dimensional detector plane, and at least one two-dimensional plane intermediate therebetween comprising a combination of a said transmitting plane and a said detector plane, with each said pixel on said at least one intermediate plane comprising both one said identical source array and one said detector.

6. The optical communication apparatus of claim 5 wherein said first two-dimensional transmitting plane and said last two-dimensional detector plane each comprise a combination of a said transmitting plane and a said detector plane, wherein said apparatus is provided with a sequence of reflecting surfaces to transmit light emitted by a said light source on said last two-dimensional detector plane to a detector on any of said first two-dimensional plane and intermediate planes, and wherein a detector in a given pixel on said last two-dimensional detector plane is adapted to energize at least one light source of said source array in said given pixel.

7. The optical communication apparatus of claim 5 comprising:

(a) a first bus comprising

(1) said first two-dimensional transmitting plane,

(2) said last two-dimensional detector plane, and

(3) said at least one two-dimensional plane intermediate therebetween comprising a plurality of pixels, each said pixel comprising both said identical source array and said detector;

(b) a second bus comprising

(1) said first two-dimensional transmitting plane,

(2) said last two-dimensional detector plane, and

(3) said at least one two-dimensional plane intermediate therebetween comprising a plurality of pixels, each said pixel comprising both said identical source array and said detector;

(c) said first bus having a direction of propagation opposite in direction to that of said second bus; and

(d) a plurality of switching network nodes, each said node connecting a plane of said first bus with a plane of said second bus such that said first transmitting plane of said first bus is connected through a said node to said last detector plane of said second bus, said first transmitting plane of said second bus is connected through a said node to said last detector plane of said first bus, and all intermediate planes are connected to each other through a single node or a plurality of nodes, so as to permit any light source on a plane of one bus to access a detector on any plane of that bus or on any plane of the other bus.

8. The optical communicating apparatus of claim 2 wherein each said identical source array comprises a plurality of vertical-cavity surface-emitting lasers, each laser emitting at a different wavelength from the others in that array.

9. The optical communicating apparatus of claim 2 wherein only one light source in a said source array is turned "ON" at a time by a common driver.

10. The optical communicating apparatus of claim 9 wherein each said pixel comprises (a) said source array, (b) said common driver electrically associated with each said light source in said source array and adapted to receive an input signal from a network node, (c) said detector, and (d) receiver electronics for outputting a signal from said detector to a network node.

11. The optical communicating apparatus of claim 2 wherein all light sources in a said source array are turned "ON" simultaneously by a common driver and all said light sources transmit the same data.

12. The optical communicating apparatus of claim 11 wherein each said pixel comprises (a) said source array, (b) said common driver electrically associated with each said light source in said source array and adapted to receive an input signal from a network node, (c) said detector, and (d) receiver electronics for outputting a signal from said detector to a network node.

13. The optical communicating apparatus of claim 2 wherein all light sources in a said source array are turned "ON" simultaneously by separate drivers and all said light sources transmit different data.

14. The optical communicating apparatus of claim 13 wherein each said pixel comprises (a) said source array, (b) each said separate driver electrically associated with a said light source in said source array and adapted to receive an input signal from a network node, (c) said detector, and (d) receiver electronics for outputting a signal from said detector to a network node.

15. The optical communicating apparatus of claim 2 wherein all pixels on a given plane are electrically connected to a network node.

16. The optical communicating apparatus of claim 2 wherein said pixels on a given plane are configured as either rows or columns and wherein each row or column is electrically connected to a network node.

17. The optical communicating apparatus of claim 16 wherein said pixels on each plane are configured alternatingly as either rows or columns, to permit communication between a single row or column node and all column or row nodes by combining both wavelength division multiplexing and space division multiplexing.

18. The optical communicating apparatus of claim 2 wherein each pixel on a given plane is electrically connected to a network node.

19. The optical communicating apparatus of claim 1 wherein each detector arranged behind another comprises a III-V compound semiconductor of different composition so as to provide said wavelength selectivity.

20. The optical communicating apparatus of claim 19 wherein each said detector comprises material selected from the group consisting of Ga_x Al_1-x As, and In_x Ga_1-x AS, and In_x Ga_1-x As_y P_1-y, where the values of x and y are independently varied to provide said wavelength selectivity.

21. The optical communicating apparatus of claim 1 wherein each detector arranged behind another comprises a III-V compound semiconductor quantum well detector so as to steepen the detector roll-off at long wavelengths and to provide said wavelength selectivity.

22. The optical communicating apparatus of claim 21 wherein each said derector comprises material selected from the group consisting of Ga_x Al_1-x As, In_x Ga_1-x As and In_x --Ga_1-x As_y P_1-y, where the values of x and y are independently varied to provide said wavelength selectivity.

23. Optical communication apparatus for simultaneously and reconfigurably establishing optical communication channels, comprising:

(a) at least one two-dimensional transmitting plane, each transmitting plane provided with a plurality of pixels, each pixel comprising an identical source array comprising a plurality of vertical-cavity surface-emitting lasers, each laser emitting at a different wavelength from the other in that array, each plane comprising a substrate consisting essentially of semiconductor material transparent to all wavelengths emitted;

(b) at least two two-dimensional detector planes, each detector plane behind another and all detector planes behind said at least one transmitting plane, each detector plane provided with a plurality of said wavelength-selective detectors, each detector on each of said two-dimensional detector planes associated with a given pixel on a previous said two-dimensional transmitting plane and having a cut-off in wavelength detection that increases in wavelength for detector planes further away from said transmitting plane, each detector comprising a III-V compound semiconductor of different composition so as to provide said wavelength selectivity, each plane comprising a substrate consisting essentially of semiconductor material transparent to all wavelengths emitted; and

(c) a plurality of supporting substrates separating said planes, said substrates comprising a material transparent to all wavelengths emitted.

24. The optical communicating apparatus of claim 23 wherein each plane consists essentially of semiconductor material selected from the group consisting of GaAs, InP, and Si.

25. The optical communicating apparatus of claim 23 wherein each detector comprises a material selected from the group consisting of Ga_1-x Al_x As, In_x Ga_1-x As, and In_x Ga_1-x As_y P_1-y, where the values of x and y are independently varied to provide said wavelength selectivity.

26. Optical communication apparatus for simultaneously and reconfigurably establishing optical communication channels, comprising a plurality of pixels, each said pixel including an identical source array, each said array comprising a plurality of light sources, each said light source operating at a different wavelength and each said array optically associated with a plurality of wavelength-selective detectors, each said wavelength-selective detectors in said plurality wave-length-selective detectors having a different spectral response, arranged one behind another, and having a cut-off in wavelength detection that increases in wavelength for wavelength-selective detectors further away from said plurality of light sources.