Variable blazed grating

• US 6,844,974 B1
• Filed: 07/09/2002
• Issued: 01/18/2005
• Est. Priority Date: 02/02/2001
• Status: Expired due to Fees

• Current Assignee: Cheetah Omni LLC
• Original Assignee: Cheetah Omni LLC
• Inventors: Islam, Mohammed N., Kuditcher, Amos
• Primary Examiner(s): Juba, Jr., John
• Application Number:
  US10/192,248
• Time in Patent Office: 924 Days
• Field of Search: 359/900, 359/290, 359/291, 359/292, 359/295, 359/571, 359/572, 359/573, 359/223, 359/224, 359/225, 359/226, 776/51
• US Class Current: 359/573
• CPC Class Codes: G02B 26/0808 by means of one or more diffracting elements
• CPC Class Codes: G02B 6/12009 comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides
• CPC Class Codes: G02B 6/2932 comprising a directional router, e.g. directional coupler, circulator
• CPC Class Codes: G02B 6/29322 Diffractive elements of the tunable type G02B6/02195 takes precedence; optical modulation devices based on a change of the optical properties of the medium G02F1/00
• CPC Class Codes: Y10S 359/90 Methods

Abstract

In one aspect of the invention, an apparatus operable to provide optical signal processing includes an inner conductive layer including an at least substantially conductive material and a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns. At least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a diffraction of the input optical signal wherein a majority of the diffracted input signal is communicated in one direction.

Claims

1. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material and a plurality of electrically coupled first conductors; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein each of the plurality of electrically coupled first conductors are associated with a separate one of at least some of the plurality of at least partially reflective mirror strips and disposed approximately inwardly from a first edge of the associated mirror strip; and

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the inner conductive layer and at least the first edges of the associated mirror strips to create an electrostatic force tending to rotate the first edges of the mirror strips toward the associated first conductor resulting in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal.

2. The apparatus of claim 1, wherein the inner conductive layer further comprises a plurality of electrically coupled second conductors, each associated with alternate ones of the mirror strips and disposed inwardly from at least a second edge opposite the first edge of the alternate mirror strips, wherein the second conductors operate to facilitate a voltage differential between the second conductors and the associated alternate mirror strips to create an electrostatic force tending to move the alternate strips inwardly relative to strips adjacent to the alternate mirror strips.

3. The apparatus of claim 1, wherein the rotation of the strips creates a periodicity of the apparatus wherein an angle of reflection of the reflected signal portions is approximately equal to an angle of incidence of the input optical signal.

4. The apparatus of claim 1, wherein the partial rotation causes a majority of reflected portions of the input signal to constructively interfere with one another after the strips have been partially rotated to result in an output port switching from receiving approximately no signal to receiving the combination of constructively interfering reflected signal portions.

5. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position outwardly from an inner conductive layer, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction, wherein the inner conductive layer comprises a plurality of electrically coupled first conductors, each associated with a separate mirror strip and disposed approximately inwardly from a first edge of the associated strip, wherein rotating the mirror strips comprises applying one of a plurality of selectable non-zero voltage differentials between at least a first edge of each of the mirror strips and an inner conductive layer disposed inwardly from the first edges of the mirror strips, the voltage differential creating an electrostatic force tending to rotate the first edge toward the inner conductive layer;

wherein the control signal comprises a voltage operable to create the one of the plurality of selectable non-zero voltage differentials between the at least the first edges of the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles attenuatins of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal.

6. The method of claim 5, wherein the inner conductive layer further comprises a plurality of electrically coupled second conductors, each associated with alternate ones of the mirror strips and disposed inwardly from at least a second edge opposite the first edge of the alternate mirror strips, wherein the second conductors operate to facilitate a voltage differential between the second conductors and the associate alternate mirror strips to create an electrostatic force tending to move the alternate strips inwardly relative to strips adjacent to the alternate mirror strips.

7. The method of claim 5, wherein the angle THETA results in a periodicity of the apparatus wherein an angle of reflection of the reflected signal portions is approximately equal to an angle of incidence of the input optical signal.

8. The method of claim 5, wherein the partial rotation causes a majority of reflected portions of the input signal constructively interfere with one another after the strips have been partially rotated to result in an output port switching from receiving approximately no signal to receiving the combination of constructively interfering reflected signal portions.

9. An apparatus operable to provide optical signal processing, the apparatus comprising:

inner conductive layer comprising an at least substantially conductive material and a plurality of electrically coupled first conductors; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein at least some of the plurality of at least partially reflective mirror strips comprise a width that is at least 12 microns and no more than 40 microns, and wherein at least some of the strips are operable to undergo a partial rotation of more than two degrees in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein each of the plurality of electrically coupled first conductors are associated with a separate one of the plurality of at least partially reflective mirror strips and disposed approximately inwardly from a first edge of the associated mirror strip; and

wherein the control signal creates at least one of a plurality of selectable non-zero voltage differentials between the inner conductive layer and at least the first edges of the associated mirror strips to create an electrostatic force tending to rotate the first edges of the mirror strips toward the associated first conductor resulting in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal.

10. The apparatus of claim 9, wherein the input optical signal comprises a multiple wavelength optical signal.

11. The apparatus of claim 9, wherein selected angles of rotation resulting from the control signal for at least some of the plurality of strips are different than selected angles of rotation for others of the plurality of strips.

12. The apparatus of claim 9, wherein the inner conductive layer comprises a plurality of separate conductive structures, each associated with a separate one of the plurality of reflective mirror strips.

13. The apparatus of claim 9, wherein at least one of the plurality of selectable attenuations comprises an attenuation of an output ray of the optical signal.

14. The apparatus of claim 13, wherein at least one of the plurality of selectable attenuations comprises an approximately zero level of attenuation in at least one output ray of the optical signal considered after any insertion losses of the apparatus, and wherein at least one of the selectable attenuations comprises an approximately full attenuation in at least one output ray of the optical signal.

15. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position and disposed outwardly from an inner conductive layer; and

rotating at least one of the plurality of mirror strips from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction, the strips having a maximum rotation angle that is greater than two degrees, wherein rotating at least one of the plurality of mirror strips comprises applying one of a plurality of selectable non-zero voltage differentials between at least a first edge of each mirror strip and an inner conductive layer disposed inwardly from the first edges of the mirror strips, the voltage differential creating an electrostatic force tending to rotate the first edge toward the inner conductive layer;

wherein the control signal creates at least the one of the plurality of selectable non-zero voltage differentials between the at least the first edges of the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein at least some of the plurality of at least partially reflective mirror strips comprise a width that is at least 12 microns and no more than 40 microns.

16. The method of claim 15, wherein the input optical signal comprises a multiple wavelength optical signal.

17. The method of claim 15, wherein selected angles of rotation resulting from the control signal for at least some of the plurality of strips are different than selected angles of rotation for others of the plurality of strips.

18. The method of claim 15, wherein the inner conductive layer comprises a plurality of separate conductive structures, each associated with a separate one of the plurality of reflective mirror strips.

19. The method of claim 15, wherein at least one of the plurality of selectable attenuations comprises an attenuation of an output ray of the optical signal.

20. The method of claim 19, wherein at least one of the plurality of selectable attenuations comprises an approximately zero level of attenuation in at least one output ray of the optical signal considered after any insertion losses of the apparatus, and wherein at least one of the selectable attenuations comprises an approximately full attenuation in at least one output ray of the optical signal.

21. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein each of the mirror strips comprises;

a layer of electrically insulating material;

a first portion of at least partially reflective and at least substantially conductive material disposed outwardly from a first edge of the insulating layer;

a second portion of at least partially reflective material disposed outwardly from the insulating layer and separated from the first portion by a channel;

wherein a voltage differential between the first portion and the inner conductive layer operates to create an electrostatic force between the first portion and the inner conductive layer tending to rotate the first portion toward the inner conductive layer.

22. The apparatus of claim 21, wherein the second portion is electrically coupled to the inner conductive layer.

23. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein each of the mirror strips comprises;

an inner surface facing the inner conductive layer; and

an outer surface joining the inner surface at an angle, wherein the outer surfaces of two adjacent strips are each operable to receive a portion of an optical input signal and to reflect the received portion at an output angle; and

wherein alternate ones of the mirror strips are operable to move relative to adjacent mirror strips by a selected distance to create a desired phase difference between the reflected beam portions.

24. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction;

wherein each of the mirror strips comprises;

a layer of electrically insulating material;

a first portion of at least partially reflective and at least substantially conductive material disposed outwardly from a first edge of the insulating layer;

a second portion of at least partially reflective material disposed outwardly from the insulating layer and separated from the first portion by a channel; and

wherein a voltage differential between the first portion and the inner conductive layer operates to create an electrostatic force between the first portion and the inner conductive layer tending to rotate the first portion toward the inner conductive layer.

25. The method of claim 24, wherein the second portion is electrically coupled to the inner conductive layer.

26. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction;

wherein each of the mirror strips comprises;

an inner surface facing the inner conductive layer; and

an outer surface joining the inner surface at an angle, wherein the outer surfaces of two adjacent strips are each operable to receive a portion of an optical input signal and to reflect the received portion at an output angle; and

wherein alternate ones of the mirror strips are operable to move relative to adjacent mirror strips by a selected distance to create a desired phase difference between the reflected beam portions.

27. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the inner conductive layer comprises a continuous layer of an at least substantially conductive material disposed inwardly from the plurality of mirror strips.

28. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position outwardly from an inner conductive layer, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the inner conductive layer comprises a continuous layer of an at least substantially conductive material disposed inwardly from the plurality of mirror strips.

29. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material and a plurality of electrically coupled first conductors; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein at least some of the strips are operable to undergo a partial rotation of more than two degrees in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein each of the plurality of electrically coupled first conductors are associated with a separate one of at least some of the plurality of at least partially reflective mirror strips and disposed approximately inwardly from a first edge of the associated mirror strip; and

wherein the control signal creates at least one of a plurality of selectable non-zero voltage differentials between the inner conductive layer and at least the first edges of the associated mirror strips to create an electrostatic force tending to rotate the first edges of the mirror strips toward the associated first conductor resulting in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the one direction comprises an output fiber from the apparatus.

30. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position and disposed outwardly from an inner conductive layer; and

rotating at least one of the plurality of mirror strips from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction, the strips having a maximum rotation angle that is greater than two degrees, wherein rotating at least one of the plurality of mirror strips comprises applying one of a plurality of selectable non-zero voltage differentials between at least a first edge of each mirror strip and an inner conductive layer disposed inwardly from the first edges of the mirror strips the voltage differential creating an electrostatic force tending to rotate the first edge toward the inner conductive layer;

wherein the control signal creates the one of the plurality of selectable non-zero voltage differentials between the at least the first edges of the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the one direction comprises an output fiber from the apparatus.

31. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein at least some of the strips are operable to undergo a partial rotation of more than two degrees in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction, and wherein each of the mirror strips comprises;

a layer of electrically insulating material;

a first portion of at least partially reflective and at least substantially conductive material disposed outwardly from a first edge of the insulating layer;

a second portion of at least partially reflective material disposed outwardly from the insulating layer and separated from the first portion by a channel; and

wherein the control signal creates one of a plurality of selectable non-zero voltage differentials between the first portion and the inner conductive layer tending to rotate the first portion toward the inner conductive layer resulting in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal.

32. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein at least some of the strips are operable to undergo a partial rotation of more than two degrees in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction, wherein each of the mirror strips comprises;

an inner surface facing the inner conductive layer; and

an outer surface joining the inner surface at an angle, wherein the outer surfaces of two adjacent strips are each operable to receive a portion of an optical input signal and to reflect the received portion at an output angle;

wherein alternate ones of the mirror strips are operable to move relative to adjacent mirror strips by a selected distance to create a desired phase difference between the reflected beam portions; and

wherein the control signal creates at least one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal.

33. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the rotation of the mirror strips creates a periodicity of the apparatus wherein an angle of reflection of the reflected signal portions is approximately equal to an angle of incidence of the input optical signal.

34. An apparatus operable to provide optical signal processing, the apparatus comprising:

an inner conductive layer comprising an at least substantially conductive material; and

a plurality of at least partially reflective mirror strips disposed outwardly from the inner conductive layer and operable to receive an input optical signal, wherein none of the plurality of strips has a width greater than 40 microns and wherein at least some of the strips are operable to undergo a partial rotation in response to a control signal, the partial rotation resulting in a reflection of the input optical signal wherein a majority of the reflected input signal is communicated in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the partial rotation causes a majority of reflected portions of the input signal to constructively interfere with one another after the mirror strips have been partially rotated to result in an output port switching from receiving approximately no signal to receiving the combination of constructively interfering reflected signal portions.

35. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position outwardly from an inner conductive layer, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the angle THETA results in a periodicity of the apparatus wherein an angle of reflection of the reflected signal portions is approximately equal to an angle of incidence of the input optical signal.

36. A method of processing optical signals using a blazed structure, the method comprising:

receiving an optical signal at a plurality of at least partially reflective mirror strips residing in a first position outwardly from an inner conductive layer, wherein none of the plurality of strips has a width of more than 40 microns; and

rotating the mirror strips by an angle THETA from the first position in response to a control signal to create a plurality of reflected signal portions, the majority of the reflected signal portions being reflected in one direction;

wherein the control signal comprises a voltage operable to create one of a plurality of selectable non-zero voltage differentials between the mirror strips and the inner conductive layer to result in one of a plurality of selectable angles of rotation of the mirror strips, and a corresponding one of a plurality of selectable attenuations of the input signal; and

wherein the partial rotation causes a majority of reflected portions of the input signal constructively interfere with one another after the strips have been partially rotated to result in an output port switching from receiving approximately no signal to receiving the combination of constructively interfering reflected signal portions.