Method and device for switching wavelength division multiplexed optical signals using two-dimensional micro-electromechanical mirrors

• US 6,707,594 B2
• Filed: 05/10/2002
• Issued: 03/16/2004
• Est. Priority Date: 09/20/2000
• Status: Expired due to Fees

• Current Assignee: General Nutronics Incorporated (Harbin Pharmaceutical Group Company Limited)
• Original Assignee: General Nutronics Incorporated (Harbin Pharmaceutical Group Company Limited)
• Inventors: Holmes, Richard B.
• Primary Examiner(s): Spector, David N.
• Application Number:
  US10/144,171
• Publication Number:
  US 20030007234A1
• Time in Patent Office: 676 Days
• Field of Search: 359/291, 359/634, 385/17, 385/18, 398/45, 398/48, 398/58
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3516 the reflective optical element moving along the beam path, e.g. controllable diffractive effects using multiple micromirrors within the beam
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays 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 6/3588 of the processed beams, i.e. controlling during switching of orientation, alignment, or beam propagation properties such as intensity, size or shape
• CPC Class Codes: G02B 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0024 using space switching
• CPC Class Codes: H04Q 2011/0039 Electrical control

Abstract

A switch device and method is disclosed that is capable of switching wavelength division multiplexed optical signals. The device comprises a switch element that includes a two-dimensional micro-electromechanical mirror. The two-dimensional micro-electromechanical mirror is adapted to reflect an optical signal so that it is directed to a selected target. The switch element may also comprise a beam splitter and a plurality of wave plates. The beam splitter is adapted to transmit light in one polarization and reflect light in another polarization. The wave plates are adapted to change the polarization of the light so that the beam splitter either reflects or transmits the light.

Claims

1. An optical switch element for use with at least one source, the source being adapted to transmit an optical signal to the optical switch element, and a plurality of targets, the targets being adapted to receive the optical signal from the optical switch device, the optical switch device comprising:

(A) a beam splitter, the beam splitter being adapted to transmit light in a first predetermined polarization and reflect light in a second predetermined polarization;

(B) a first wave plate positioned on an optical path between the source and the beam splitter, the first wave plate being adapted to alter polarization of the light transmitted by the source so that it is reflected by the beam splitter, wherein light transmitted by the source passes through the wave plate and is reflected by the beam splitter;

(C) a micro-electromechanical mirror positioned to receive light reflected by the beam splitter, the micro-electromechanical mirror being adapted to selectively reflect light in a plurality of paths, the paths corresponding to the positions of the plurality of targets;

(D) a second wave plate positioned on an optical path between the micro-electromechanical mirror and the beam splitter, the second wave plate being adapted to alter polarization of the light reflected by the micro-electromechanical mirror so that it is transmitted by the beam splitter, wherein light reflected by the micro-electromechanical mirror passes through the second wave plate and is transmitted by the beam splitter.

2. The optical switch element of claim 1, further comprising a controller in communication with the micro-electromechanical mirror, the controller being adapted to determine a target for an optical signal and cause the micro-electromechanical mirror to reflect the signal to the target.

3. The optical switch element of claim 2, further comprising a detector positioned to receive light from the source and in communication with the controller, the detector being configured to allow the controller to receive information from an optical signal.

4. The optical switching element of claim 1, further comprising a lenslet array between the source and the beam splitter, the lenslet array being adapted to transmit collimated light to the first micro-electromechanical mirror.

5. The optical switching element in claim 4, further comprising a lens positioned between the micro-electromechanical mirror and the lenslet array, wherein light reflected by the micro-electromechanical mirror is imaged on the lenslet array.

6. The optical switch element of claim 1, wherein the micro-electromechanical mirror is a two-dimensional micro-electromechanical mirror.

7. An optical switch device, comprising:

(A) at least one source, the source being adapted to transmit an optical signal;

(B) a plurality of targets, the targets being adapted to receive the optical signal; and

(C) at least a first and second switch element, each switch element comprising a micro-electromechanical mirror positioned to receive light from the source, the micro-electromechanical mirror being adapted to selectively reflect light in a plurality of paths, the paths corresponding to the positions of the plurality of targets; and

(D) a beam splitter positioned to reflect optical signals to the micro-electromechanical mirror of the first switch element, the beam splitter being adapted to reflect light within a predetermined range of wavelengths and allow light outside of the predetermined range of wavelengths to pass through the beam splitter, the second switch element being positioned to receive optical signals that pass through the beam splitter and transmit optical signals to the plurality of targets.

8. The optical switch device of claim 7, wherein each switch element further comprises a controller in communication with the micro-electromechanical mirror, the controller being adapted to determine a target for an optical signal and cause the micro-electromechanical mirror to reflect light to the target.

9. The optical switch device of claim 8, wherein each switch element further comprises a detector positioned to receive light from the source and in communication with the controller, the detector being configured to allow the controller to obtain information from an optical signal.

10. The optical switch device of claim 7, wherein each switch element further comprises:

(A) a beam splitter, the beam splitter being adapted to transmit light in a first predetermined polarization and reflect light in a second predetermined polarization;

(B) a first wave plate positioned on an optical path between the source and the beam splitter, the first wave plate being adapted alter polarization of the light transmitted by the source so that it is reflected by the beam splitter, wherein light transmitted by the source passes through the wave plate and is reflected by the beam splitter; and

(C) a second wave plate positioned between the micro-electromechanical mirror and the beam splitter, the second wave plate being adapted to alter polarization of the light reflected by the micro-electromechanical mirror so that it is transmitted by the beam splitter, wherein light reflected by the micro-electromechanical mirror passes through the second wave plate and is transmitted by the beam splitter.

11. An array of optical switch elements, the array comprising:

(A) at least a first and second switch element, each switch element comprising a micro-electromechanical mirror positioned to receive light from a source, the micro-electromechanical mirror being adapted to selectively reflect light into a plurality of paths, the paths corresponding to the positions of a plurality of targets; and

(B) a beam splitter, the beam splitter being adapted to reflect light of a predetermined wavelength and allow light outside of the predetermined wavelength to pass through the beam splitter, the beam splitter being positioned to reflect light transmitted by a source to the micro-electromechanical mirror of the first switch element, the micro-electromechanical mirror of the second switch element being positioned to receive light that passes through the beam splitter.

12. The optical switch device of claim 11, wherein each switch element further comprises a controller in communication with the micro-electromechanical mirror, the controller being adapted to determine a target for an optical signal and cause the micro-electromechanical mirror to reflect light to the target.

13. The optical switch device of claim 12, wherein each switch element further comprises a detector positioned to receive light from the source and in communication with the controller, the detector being configured to allow the controller to obtain information from an optical signal.

14. The optical switch device of claim 11, wherein each switch element further comprises:

(A) a beam splitter, the beam splitter being adapted to transmit light in a first predetermined polarization and reflect light in a second predetermined polarization;

(B) a first wave plate positioned on an optical path between the source and the beam splitter, the first wave plate being adapted to alter polarization of the light transmitted by the source so that it is reflected by the beam splitter, wherein light transmitted by the source passes through the wave plate and is reflected by the beam splitter; and

(C) a second wave plate positioned on an optical path between the micro-electromechanical mirror and the beam splitter, the second wave plate being adapted alter polarization of the light reflected by the micro-electromechanical mirror so that it is transmitted by the beam splitter, wherein light reflected by the micro-electromechanical mirror passes through the second wave plate and is transmitted by the beam splitter.

15. A method of switching optical signals, the method comprising the following steps:

(A) providing at least a first and second switch element, each switch element comprising a micro-electromechanical mirror positioned to receive light from a source, the micro-electromechanical mirror being adapted to selectively reflect light in a plurality of paths, the paths corresponding to the positions of a plurality of targets;

(B) causing light of a predetermined range of wavelengths to be received by the first switch element;

(C) causing light outside of the predetermined range of wavelengths to be received by the second switch element;

(D) determining a target to which to transmit the optical signal; and

(E) causing the micro-electromechanical mirror in at least one of the switch elements to reflect the optical signal along a path, the path of the reflected optical signal corresponding to a position of a target, wherein the optical signal is transmitted to the target.

16. The method of claim 15 further comprising:

(A) wherein at least one of the first and second switch element further comprises a beam splitter, the beam splitter being adapted to transmit light in a first predetermined polarization and reflect light in a second predetermined polarization;

(B) causing the optical signal to be polarized in the first predetermined polarization wherein the optical signal is reflected by the beam splitter to the micro-electromechanical mirror; and

(C) causing the optical signal to be polarized in the second predetermined polarization, wherein light reflected by the micro-electromechanical mirror is transmitted by the beam splitter.

17. An optical switch element for use with at least one source, the source being adapted to transmit an optical signal to the optical switch element, and a plurality of targets, the targets being adapted to receive the optical signal from the optical switch device, the optical switch device comprising:

(A) a beam splitter, the beam splitter being adapted to transmit light in a first predetermined polarization and reflect light in a second predetermined polarization;

(B) a first wave plate positioned on an optical path between the source and the beam splitter, the first wave plate being adapted to alter polarization of the light transmitted by the source so that it is reflected by the beam splitter, wherein light transmitted by the source passes through the wave plate and is reflected by the beam splitter;

(C) a direction-altering device positioned to receive light reflected by the beam splitter, the direction-altering device being adapted to selectively direct light in a plurality of paths, the paths corresponding to the positions of the plurality of targets;

(D) a second wave plate positioned between the direction-altering device and the beam splitter, the second wave plate being adapted to alter polarization of the light directed by the direction-altering device so that it is transmitted by the beam splitter, wherein light directed by the direction-altering device passes through the second wave plate and is transmitted by the beam splitter.

18. The optical switch element of claim 17 wherein the direction-altering device comprises a micro-electromechanical mirror.

19. The optical switch element of claim 17 wherein the direction-altering device comprises a gas bubble device.