MEMS optical switches having obliquely angled inputs and outputs relative to a face thereof and moveable reflectors with parallel positions therein and methods of forming same

• US 6,636,655 B2
• Filed: 08/24/2001
• Issued: 10/21/2003
• Est. Priority Date: 08/29/2000
• Status: Expired due to Fees

• Current Assignee: Memscap Incorporated
• Original Assignee: Memscap Incorporated
• Inventors: Walters, Mark, Zhu, Terry D.
• Primary Examiner(s): Healy, Brian
• Assistant Examiner(s): WONG, TINA MEI SENG
• Application Number:
  US09/939,060
• Publication Number:
  US 20020048426A1
• Time in Patent Office: 788 Days
• Field of Search: 385/18, 385/17, 385/19, 385/22
• US Class Current: 385/18
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation

Abstract

MEMS optical switches can include a substrate having first and second opposing faces and at least one side therebetween. An input is obliquely angled towards the face and optically couples optical radiation towards the face. A movable reflector is on the face and moves from a first position to a second position that is parallel to the first position to reflect the optical radiation from the input to provide reflected optical radiation. A output is obliquely angled away from the face and optically couples the reflected optical radiation away from the face.

Claims

1. A MEMS optical switch comprising:

a substrate having first and second opposing faces and a plurality of moveable reflectors on the first face;

an input that is obliquely angled towards the first face adjacent thereto and that optically couples optical radiation towards the first face;

at least one of the plurality of moveable reflectors on the first face being configured to move from a first position to a second position that is parallel to the first position to reflect the optical radiation from the input to provide reflected optical radiation; and

an output that is obliquely angled away from the first face adjacent thereto and that optically couples the reflected optical radiation away from the first face.

2. A MEMS optical switch according to claim 1 wherein the moveable reflector moves between the first and second positions in a direction that is parallel to the first face.

3. A MEMS optical switch according to claim 1 further comprising:

a member that extends in a direction on the first face and is coupled to the moveable reflector; and

an actuator on the first face and coupled to the member, wherein the actuator moves the moveable reflector between the first and second positions in the direction parallel to the first face.

4. A MEMS optical switch according to claim 3 wherein a thickness of a reflective portion of the moveable reflector that reflects the optical radiation is less than a thickness of the member.

5. A MEMS optical switch according to claim 4 wherein the reflective portion comprises metal and the member comprises silicon.

6. A MEMS optical switch according to claim 1 further comprising:

a member on the first face and coupled to the moveable reflector; and

an actuator on the first face and coupled to the member, wherein the actuator rotates the member in a direction that is parallel to the first face to move the moveable reflector between the first and second positions.

10. A MEMS optical switch according to claim 1 further comprising:

a recess in the first face aligned with the moveable reflector in the second position.

28. A MEMS optical switch according to claim 1 further comprising:

a recess in the first face of the substrate having a recess bottom beneath the moveable reflector.

29. A MEMS optical switch according to claim 1 wherein the moveable reflector includes first and second reflective surfaces on opposite sides thereof.

7. A MEMS optical switch comprising:

a substrate having first and second opposing faces and at least one side therebetween;

an input that is obliquely angled towards the first face adjacent thereto and that optically couples optical radiation towards the first face;

a movable reflector on the first face that is configured to move from a first position to a second position that is parallel to the first position to reflect the optical radiation from the input to provide reflected optical radiation;

an output that is obliquely angled away from the first face adjacent thereto and that optically couples the reflected optical radiation away from the first face; and

a reflector on the first face wherein the moveable reflector is cantilevered over the reflector in the second position.

8. A MEMS optical switch according to claim 7 further comprising:

a recess in the first face, wherein the reflector is in the recess.

9. A MEMS optical switch comprising:

a substrate having first and second opposing faces and at least one side therebetween;

an input that is obliquely angled towards the first face adjacent thereto and that optically couples optical radiation towards the first face;

a movable reflector on the first face that is configured to move from a first position to a second position that is parallel to the first position to reflect the optical radiation from the input to provide reflected optical radiation;

an output that is obliquely angled away from the first face adjacent thereto and that optically couples the reflected optical radiation away from the first face, wherein the reflected optical radiation comprises first reflected optical radiation and wherein the output comprises a first output;

a reflector, on the first face beneath the moveable reflector, that reflects the optical radiation from the input when the moveable reflector is in the first position to provide second reflected optical radiation; and

a second output, obliquely angled away from the first face adjacent thereto, that optically couples the second reflected optical radiation away from the first face.

11. A 2×

2 MEMS optical switch comprising;

a substrate having first and second opposing faces and at least one side therebetween;

first and second inputs, obliquely angled towards the first face adjacent thereto and that couple first and second optical radiation towards the first face;

first and second outputs, obliquely angled away from the first face adjacent thereto, wherein first and second optical beam paths are defined to include the first and second inputs and outputs respectively; and

a movable reflector on the first face that is configured to move from a first position to a second position that is parallel to the first position to reflect optical radiation from at least one of the optical beam paths to one of the outputs.

12. A MEMS optical switch according to claim 11 wherein the moveable reflector moves between the first and second positions in a direction that is parallel to the first face.

30. A 2×

2 MEMS optical switch according to claim 11 further comprising;

a plurality of moveable reflectors on the first face of the substrate.

13. A 2×

2 MEMS optical switch comprising;

a substrate having first and second opposing faces and at least one side therebetween;

first and second inputs, obliquely angled towards the first face adjacent thereto and that couple first and second optical radiation towards the first face;

first and second outputs, obliquely angled away from the first face adjacent thereto, wherein first and second optical beam paths are defined to include the first and second inputs and outputs respectively;

a movable reflector on the first face that is configured to move from a first position to a second position that is parallel to the first position to reflect optical radiation from at least one of the optical beam paths to one of the outputs; and

a reflector on the first face beneath the moveable reflector, wherein the moveable reflector is cantilevered over the reflector when in the second position.

14. A MEMS optical switch according to claim 13 further comprising:

a recess in the first face, wherein the reflector is in the recess.

15. A MEMS optical switch according to claim 13 wherein a first optical beam path is defined from the first input to the first output and a second optical beam path is defined from the second input to the second output, wherein the moveable reflector comprises a first reflective surface facing away from the reflector and a second reflective surface, opposite the first reflective surface, that faces towards the reflector;

wherein first optical radiation is reflected off the reflector from the first input to the first output along the first optical beam path and second optical radiation is reflected off the reflector from the second input to the second output along the second optical beam path when the moveable reflector is in the first position;

wherein the first optical radiation is reflected off the reflector to the second reflective surface along the first optical beam path and off the reflector to the second output along the second optical beam path when the moveable reflector is in the second position; and

wherein the second optical radiation is reflected off the first reflective surface to the first output when the moveable reflector is in the second position.

16. A 3×

3 blocking MEMS optical switch comprising;

a substrate having first and second opposing faces and at least one side therebetween;

first, second and third inputs, obliquely angled towards the first face adjacent thereto, that optically couple first, second, and third optical radiation towards the first face;

first, second, and third outputs, obliquely angled away from the first face adjacent thereto, wherein first, second, and third optical beam paths are defined to include the first, second and third inputs and outputs respectively; and

first and second movable reflectors on the first face that move from associated first positions to associated second positions that are parallel to the first positions to reflect optical radiation from at least one of the optical beam paths to one of the outputs.

23. A 3×

3 blocking MEMS optical switch according to claim 16, wherein at least one of the optical beam paths defines one of a 45 degree angle, a 40 degree angle, and a 60 degree angle with the first face.

24. A 3×

3 blocking MEMS optical switch according to claim 16, wherein at least one of moveable reflectors is separated from the first face by one of about 200 μ

m, about 208 μ

m, and about 238 μ

m.

31. A 3×

3 blocking MEMS optical switch according to claim 16 further comprising;

a plurality of moveable reflectors on the first face of the substrate.

17. A 3×

3 blocking MEMS optical switch comprising;

a substrate having first and second opposing faces and at least one side therebetween;

first, second and third inputs, obliquely angled towards the first face adjacent thereto, that optically couple first, second, and third optical radiation towards the first face;

first, second, and third outputs, obliquely angled away from the first face adjacent thereto, wherein first, second, and third optical beam paths are defined to include the first, second and third inputs and outputs respectively;

first and second movable reflectors on the first face that move from associated first positions to associated second positions that are parallel to the first positions to reflect optical radiation from at least one of the optical beam paths to one of the outputs; and

a reflector on the first face beneath the first and second moveable reflectors, wherein the reflector reflects optical radiation along the first, second, and third optical beam paths.

18. A 3×

3 blocking MEMS optical switch according to claim 17;

wherein optical radiation is reflected from the first input to the second output and optical radiation is reflected from the second input to the first output when the first moveable reflector is in the associated second position at an intersection of the first and second optical beam paths and when the second moveable reflector is in the associated first position.

19. A 3×

3 blocking MEMS optical switch according to claim 17;

wherein optical radiation is reflected from the first input to the third output and optical radiation is reflected from the second input to the first output and optical radiation is reflected from the third input to the second output when the first moveable reflector is in the associated second position at an intersection of the first and second optical beam paths and when the second moveable reflector is in the associated second position at an intersection of the second and third optical beam paths.

20. A 3×

3 blocking MEMS optical switch according to claim 17 wherein the first and second moveable reflectors are cantilevered over the reflector in the second position.

21. A 3×

3 blocking MEMS optical switch according to claim 17 further comprising;

a recess in the first face, wherein the reflector is in the recess; and

wherein the first and second moveable reflectors are cantilevered over the recess from opposing sides of the recess.

22. A 3×

3 blocking MEMS optical switch according to claim 21 wherein the first and second moveable reflectors are unaligned with one another on the opposing sides of the recess.

25. A method of forming a MEMS optical switch comprising:

forming a member on a first face of a substrate;

etching around the member to form a recess in the first face of the substrate adjacent to the member;

forming a reflector in the recess;

forming a first reflective surface on a first side of the member that faces away from the reflector;

etching through the substrate and the reflector from a second face of the substrate that is opposite the first face to expose a second side of the member opposite the first side; and

forming a second reflective surface on the second side of the member that faces towards the reflector.

26. A method according to claim 25 wherein etching through the substrate and the reflector from a second face of the substrate comprises etching through the substrate to form a hole aligned to an initial position of the member.

27. A method according to claim 26 wherein the hole is elongated in a direction in which the member is configured to move.