Two-by-two optical routing element using two-position MEMS mirrors

• US 7,177,498 B2
• Filed: 03/13/2002
• Issued: 02/13/2007
• Est. Priority Date: 03/13/2002
• Status: Expired due to Fees

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: Altera Corporation (Intel Corporation)
• Inventors: Cizek, Nicholas Charles
• Primary Examiner(s): Song; Sarah
• Application Number:
  US10/098,805
• Publication Number:
  US 20030174941A1
• Time in Patent Office: 1,798 Days
• Field of Search: 385 16- 24, 385/140, 385/36, 385/37, 359/836
• US Class Current: 385/31
• CPC Class Codes: G02B 6/04 formed by bundles of fibres G02B6/24 takes precedence
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/29307 components assembled in or forming a solid transparent unitary block, e.g. for facilitating component alignment
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/352 the reflective optical element having a shaped reflective surface, e.g. a reflective element comprising several reflective surfaces or facets that function together
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/3568 characterised by the actuating force
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841

Abstract

Retroreflecting elements adapted for use in two-by-two optical routing elements. Each retroreflecting element is configured to selectively retroreflect two optical rays. A first reflective surface, such as may be provided by a mirror, is inclined with respect to a reference plane. A second reflective surface, such as may also be provided by a mirror, is opposed to and inclined with respect to the first reflective surface. The two surfaces are configured for rotation about an axis to multiple positions such that in a first position, a first ray is retroreflected along a first path and second ray is reflected along a second path, and in a second position, the first ray is reflected along the second path and the second ray is reflected along the first path.

Claims

1. A two-by-two optical routing element for receiving, at each of a pair of input ports, light having a plurality of spectral bands, and directing selected ones of the spectral bands to either of two output ports, the two-by-two optical routing element, comprising:

a free-space optical train disposed between the input ports and the output ports providing optical paths for routing the spectral bands, the optical train having a dispersive element disposed to intercept the light traveling from the input port; and

a routing mechanism having a plurality of dynamically configurable retroreflecting elements, each such dynamically configurable retroreflecting element including;

a first reflective surface inclined with respect to an axis; and

a second reflective surface opposed to the first surface, thereby forming an included angle α

;

wherein the first reflective surface and the second reflective surface are configured for rotation together about the axis to a plurality of positions including at least a first position, a second position, and a third position;

wherein the surfaces are disposed such that when the surfaces are in the first position, a first ray is retroreflected along a first path, thereby directing a first spectral band toward a first one of the output ports, and when the surfaces are in the second position, the first ray is retroreflected along a second path, thereby directing the first spectral band toward a second one of the output ports;

wherein the surfaces are further disposed such that when the surfaces are in the first position, a second ray is retroreflected along the second path, thereby directing a second spectral band toward the second one of the output ports, and when the surfaces are in the second position, the second ray is retroreflected along the first path, thereby directing the second spectral band toward the first one of the output ports; and

wherein the surfaces are further disposed such that when the surfaces are in the third position, the first spectral band and the second spectral band are directed away from an output port.

2. The two-by-two optical routing element recited in claim 1 wherein the surfaces are formed on a common mass.

3. The two-by-two optical routing element recited in claim 1 wherein α

is substantially equal to 90°

.

4. The two-by-two optical routing element recited in claim 1, wherein at least one of the reflective surfaces has optical power.

5. The two-by-two optical routing element recited in claim 1 wherein the paths are parallel.

6. The two-by-two optical routing element recited in claim 1 wherein at least one of the paths is parallel to the axis.

7. The two-by-two optical routing element recited in claim 1 wherein the routing mechanism has a circular projection a plane.

8. The two-by-two optical routing element recited in claim 1 wherein the plurality of positions comprises a continuum of positions.

9. The two-by-two optical routing element recited in claim 8 wherein the second position is chosen for selective attenuation of the first ray.

10. The two-by-two optical routing element recited in claim 1 wherein the plurality of positions comprises a plurality of discrete positions.

11. A method for directing optical rays, comprising:

at an input port, receiving an input optical ray comprising a plurality of spectral bands;

spectrally separating the input optical ray into spectral bands;

reflecting a first optical ray from a first reflective surface inclined with respect to an axis, wherein the first optical ray comprises a first one of the spectral bands;

thereafter reflecting the first optical ray from a second reflective surface along a first optical path toward a first output port, the second reflective surface being opposed to the first surface thereby forming an included angle α

, wherein the first reflective surface and the second reflective surface are configured for rotation together about the axis to a plurality of positions;

reflecting a second optical ray from the second reflective surface, wherein the second optical ray comprises second one of the spectral bands;

thereafter reflecting the second optical ray from the first reflective surface along a second optical path toward a second output port;

rotating the surfaces to a position such that the first ray is reflected along the second path toward the second output port and the second ray is reflected along the first path toward the first output port; and

rotating the surfaces to a third position wherein the first spectral band and the second spectral band are directed away from an output port.

12. The method recited in claim 11 wherein α

is substantially equal to 90°

.

13. The method recited in claim 11 wherein the position is chosen for selective attenuation of at least one of the rays.

14. The method recited in claim 11 wherein the plurality of positions comprises a continuum of positions.

15. The method recited in claim 11 wherein the plurality of positions comprises a plurality of discrete positions.

16. A micro-electro-mechanical system device for selectively retroreflecting two input rays, the device, comprising:

first reflective means inclined with respect to a plane; and

second reflective means opposed to the first reflective means, thereby forming an included angle α

;

wherein the first and second reflective means are configured for rotation together about an axis to a plurality of positions, including at least a first position, a second position, and a third position;

wherein the first and second reflective means are disposed such that when the first and second reflective means are in the first position, a first ray is retroreflected along a first path, thereby directing a first spectral band toward a first output port, and when the first and second reflective means are in the second position, the first ray is retroreflected along a second path, thereby directing the first spectral band toward a second output port;

wherein the first and second reflective means are further disposed such that when the first and second reflective means are in the first position, a second ray is retroreflected along the second path, thereby directing a second spectral band toward the second output port, and when the first and second reflective means are in the second position, the second ray is retroreflected along the first path, thereby directing the second spectral band toward the first output port;

wherein the first and second reflective means are further disposed such that when the surfaces are in the third position, the first spectral band and the second spectral band are directed away from an output port; and

wherein the first and second reflective means comprise a micro-electro-mechanical system device.

17. The device recited in claim 16 wherein the first and second surfaces are formed on a common mass.

18. The device recited in claim 16 wherein α

is substantially equal to 90°

.