Optical switching system

• US 6,501,869 B1
• Filed: 03/14/2001
• Issued: 12/31/2002
• Est. Priority Date: 03/20/2000
• Status: Expired due to Fees

• Current Assignee: George Mason University
• Original Assignee: George Mason University
• Inventors: Athale, Ravindra
• Primary Examiner(s): NGO, HUNG NHAT
• Application Number:
  US09/805,428
• Time in Patent Office: 657 Days
• Field of Search: 385/17-22
• US Class Current: 385/18
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3562 Switch of the bypass type, i.e. enabling a change of path in a network, e.g. to bypass a failed element in the network
• CPC Class Codes: G02B 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3596 With planar waveguide arrangement, i.e. in a substrate, regardless if actuating mechanism is outside the substrate

Abstract

An optical switch is disclosed which includes hollow waveguide structures having cantilevered beam deflectors to couple light out of the waveguide plane. An array of such waveguides with deflector combinations may be fabricated on a substrate. By combining substrates, devices such as all-optical cross bar switches, image display and scanning devices may be created.

Claims

1. An optical switch comprising:

a. a plurality of optical wave.guide switches, each of said plurality of optical waveguide switches comprising;

i. an optical waveguide including;

1. a substrate having a hollow channel running through said substrate, said hollow channel having a beginning and an end;

2. a plate residing atop said hollow channel;

3. an input aperture at said beginning of said hollow channel; and

4. an output aperture at said end of said hollow channel;

ii. a plurality of micro-mechanical deflectable cantilevered beam mirrors formed in said plate oriented along said optical waveguide, said micro-mechanical deflectable cantilevered beam mirrors having;

1. a deflected position where said micro-mechanical deflectable cantilevered beam mirrors are operably deflected out of the plane of said plate into said hollow channel for intercepting an optical signal and deflecting said optical signal out of the plane of said hollow waveguide; and

2. a non-deflected position where said micro-mechanical deflectable cantilevered beam mirrors remain in the plane of said plate;

iii. a plurality of mirror apertures, each of said plurality of mirror apertures operably formed when each of said micro-mechanical deflectable cantilevered beam mirrors are in their deflected position;

b. at least two layers, each of said layers comprising at least one of said optical waveguide switches;

c. an optical waveguide switch stack comprising at least two of said layers stacked so that at least one of said plurality of mirror apertures from each of said optical waveguide switches on adjacent said layers are aligned;

d. at least one input optical interface, each of said input optical interfaces attached to one of said input apertures for receiving an optical signal from at least one external source; and

e. at least one output optical interface, each of said output optical interfaces attached to one of said output apertures for said optical signal to pass from said optical switch to at least one external receiver.

2. An optical switch according to claim 1 wherein said optical waveguide has a highly reflective coating covering said hollow channel.

3. An optical switch according to claim 1 wherein said plate has a highly reflective coating in areas covering said hollow channel.

4. An optical switch according to claim 1 wherein said input optical interface and said output optical interface includes a means for connecting an optical fiber to said optical switch.

5. An optical switch as per claim 1 wherein said plate is a membrane.

6. An optical switch as per claim 1 wherein when said micro-mechanical deflectable cantilevered beam mirrors are in said non-deflected position, said micro-mechanical deflectable cantilevered beam mirrors provide a portion of said plate covering said optical waveguide for ensuring the confinement of said optical signal inside said optical waveguide.

7. An optical switch as per claim 1 wherein the central region of said optical waveguide has a higher refractive index than the surrounding region of said optical waveguide.

8. An optical switch as per claim 1 wherein the guiding region of said optical waveguide contains a gas.

9. An optical switch as per claim 8 where said gas is air.

10. An optical switch as per claim 1 wherein said substrate has a characteristic selected from the group consisting of:

a. transparent; and

b. opaque.

11. An optical switch as per claim 1 wherein said substrate has a characteristic selected from the group consisting of:

a. metallic; and

b. insulating.

12. An optical switch as per claim 1 wherein said substrate has a structure selected from the group consisting of:

a. a crystal structure; and

b. an amorphous structure.

13. An optical switch as per claim 1 wherein said plate has a characteristic selected from the group consisting of:

a. transparent; and

b. opaque.

14. An optical switch as per claim 1 wherein said plate has a characteristic selected from the group consisting of:

a. metallic; and

b. insulating.

15. An optical switch as per claim 1 wherein said plate has a structure selected from the group consisting of:

a. a crystal structure; and

b. an amorphous structure.

16. An optical switch as per claim 1 wherein when said micro-mechanical deflectable cantilevered beam mirrors are in said deflected position, the deflection angle is 45 degrees.

17. An optical switch as per claim 1 wherein said substrate is a hollow cavity.

18. An optical switch as per claim 1, wherein said optical switch is a cross connect optical switch where:

a. one of said layers is a first layer;

b. said at least one of one of said optical waveguide switches on said first layer is a multitude of said optical waveguide switches aligned in parallel;

c. one of said layers is a second layer

d. said at least one of one of said optical waveguide switches on said second layer is a multitude of said optical waveguide switches aligned in parallel;

e. said first layer and said second layer are adjacent layers; and

f. said first layer and said second layer are aligned so that said optical waveguide switches on said first layer are perpendicular to said optical waveguide switches on said second layer.

19. An optical switch as per claim 1, wherein said optical switch is a 1×

M optical switch;

a. one of said layers is a first layer;

b. said at least one of one of said optical waveguide switches on said first layer is a single said optical waveguide switche;

c. one of said layers is a second layer

d. said at least one of one of said optical waveguide switches on said second layer has M number of said optical waveguide switches aligned in parallel;

e. said first layer and said second layer are adjacent layers; and

f. said first layer and said second layer are aligned so that said optical waveguide switch on said first layer is perpendicular to said optical waveguide switches on said second layer.

20. An optical switch as per claim 1, wherein said at least one of one of said optical waveguide switches on said at least two layer is a multitude of said optical waveguide switches integrated onto a single said substrate.

21. An optical switch as per claim 1, wherein said optical switch is an optical scanner.

22. An optical switch as per claim 1, wherein said optical signal is a time modulated optical signal.

23. An optical switch according to claim 22, wherein said micro-mechanical deflectable cantilevered beam mirrors are operably deflected in a predetermined pattern that is synchronous with said time modulated optical signal.

24. An optical switch according to claim 23, wherein said time modulated optical signal is a display signal.

25. An optical switch according to claim 1, wherein said substrate also contains other microelectronics.

26. An optical switch according to claim 24, wherein said microelectronics includes control circuitry for controlling said optical switch.

27. An optical switch according to claim 1, wherein at least part of said optical switch is fabricated using Micro lithography.

28. An optical switch according to claim 1, wherein said substrate is silicon.

29. An optical switch according to claim 28, wherein said silicon top plate is a polyimide film deposited on said substrate.