Microlens switching assembly and method

• US 6,415,068 B1
• Filed: 07/07/2000
• Issued: 07/02/2002
• Est. Priority Date: 07/07/2000
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sun, Decai
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): Doan, Jennifer
• Application Number:
  US09/610,673
• Time in Patent Office: 725 Days
• Field of Search: 385/16, 385/18, 385/23, 359/813, 359/814
• US Class Current: 385/16
• CPC Class Codes: G02B 6/3524 the optical element being refractive
• CPC Class Codes: G02B 6/3526 the optical element being a lens
• CPC Class Codes: G02B 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/3552 1x1 switch, e.g. on/off switch
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3576 Temperature or heat actuation thermal forces controlling reflecting elements in general G02B26/0866; thermo-optic devices G02F1/0147
• CPC Class Codes: G02B 6/3598 Switching means directly located between an optoelectronic element and waveguides, including direct displacement of either the element or the waveguide, e.g. optical pulse generation based on changing the optical properties of the medium G02F1/00; optical pulse generation in optical transmitters H04B10/508; optical pulse generation by controlling laser operation H01S3/00

Abstract

A microlens switching assembly and a method for optical switching uses a microlens switching assembly. The microlens switching assembly uses a microelectromechanical system-based comb drive, or other drive mechanism, to move a microlens or microlens array in a direction perpendicular to the optical axis to switch a signal between a signal source and a signal receiver. The microlens is carried by a support member that is suspended from a substrate by a pair of folded springs. This allows the microlens to be moved rapidly to provide fast switching. The signal source and the signal receiver may be optical fibers or a laser source and one or more photodetectors. In the case of optical fibers, the switching provided by the microlens switching assembly and method may be an attenuation of the signal that is received by an output optical fiber.

Claims

1. A microlens switching assembly, comprising:

at least one microlens, each microlens having an optical axis;

a signal source arranged on a first side of the at least one microlens;

a signal receiver arranged on a second side of the at least one microlens; and

at least one driver;

for each microlens, a support member that carries that microlens and is non-integral with that microlens;

wherein for each microlens, the driver for that microlens drives that microlens between a first position, in which that microlens directs a signal from the signal source to the signal receiver, and at least one other position, in which that microlens directs the signal from the signal source at least partially away from the signal receiver; and

wherein for each microlens the driver for that microlens drives the support member for that microlens in the direction perpendicular to the optical axis.

2. The microlens switching assembly of claim 1, wherein the support member is a silicon-on-insulator wafer.

3. The microlens switching assembly of claim 1, wherein, for each support member, that support member is suspended by at least one flexible structure.

4. The microlens switching assembly of claim 3, wherein, for each support member, the at least one flexible structure comprises a pair of folded springs disposed on opposite sides of the support member.

5. The microlens switching assembly of claim 1, wherein:

the signal source comprises an input optical fiber;

the signal receiver comprises an output optical fiber; and

for each microlens, the driver for that microlens drives that microlens between a first position, in which that microlens directs the signal from the input optical fiber to the output optical fiber, and at least one other position, in which that microlens directs the signal from the input optical fiber at least partially away from the output optical fiber.

6. The microlens switching assembly of claim 1, wherein:

the signal source comprises an input optical fiber;

the signal receiver comprises an array of output optical fibers; and

for each microlens, the driver for that microlens drives that microlens between a plurality of positions, wherein, for each position, that microlens directs the signal from the input optical fiber to a desired one of the output optical fibers of the array.

7. The microlens switching assembly of claim 1, wherein:

the signal source comprises a laser light source;

the signal receiver comprises a photodetector; and

for each microlens, the driver for that microlens drives that microlens between a first position, in which that microlens directs laser light from the laser light source to the photodetector, and a second position, in which that microlens directs laser light from the laser light source away from the photodetector.

8. The microlens switching assembly of claim 1, wherein:

the signal source comprises a laser light source;

the signal receiver comprises an array of photodetectors; and

for each microlens, the driver for that microlens drives that microlens between a first position and a second position for at least some of the photodetectors of the array so that microlens directs laser light from the laser light source to a desired one of the photodetectors of the array.

9. The microlens switching assembly of claim 1, wherein:

the signal receiver comprises an array of signal receivers; and

for each microlens, the driver for that microlens drives that microlens between a plurality of positions, wherein, for each position, that microlens directs the signal from the signal source to a desired one of the signal receivers of the array.

10. The microlens switching assembly of claim 1, wherein the driver comprises a microelectromechanical system-based comb drive.

11. The microlens switching assembly of claim 1, further comprising, for each microlens, a second driver that drives that microlens in a direction parallel to the optical axis of that microlens to adjust a focal point of that microlens.

12. The microlens switching assembly of claim 11, wherein the second driver for each of at least one microlens comprises at least one electrode that electrostatically moves that microlens in the direction parallel to that microlens'"'"' optical axis.

13. A microlens switching assembly, comprising:

at least one microlens, each microlens having an optical axis;

a signal source arranged on a first side of the at least one microlens;

a signal receiver arranged on a second side of the at least one microlens; and

at least one driver, each driver driving one of the at least one microlens in a direction perpendicular to that microlens'"'"' optical axis;

wherein for each microlens, the driver for that microlens drives that microlens between a first position, in which that microlens directs a signal from the signal source to the signal receiver, and at least one other position, in which that microlens directs the signal from the signal source at least partially away from the signal receiver; and

further comprising, for each microlens, a second driver that drives that microlens in a direction parallel to the optical axis of that microlens to adjust a focal point of that microlens.

14. The microlens switching assembly of claim 13, wherein the second driver for each of at least one microlens comprises at least one electrode that electrostatically moves that microlens in the direction parallel to that microlens'"'"' optical axis.

15. A method for optical switching using a microlens assembly, comprising:

transmitting a signal through a movable microlens having an optical axis;

moving the microlens in a direction perpendicular to the optical axis between a first position, in which the transmitted signal is directed towards a signal receiver, and at least one other position, in which the transmitted signal is directed at least partially away from the signal receiver; and

moving the microlens in a direction parallel to the optical axis to adjust a focal point of the microlens.

16. The method of claim 15, wherein moving the microlens to adjust the focal point comprises applying an actuation voltage to a driver that is arranged to drive the microlens in the direction parallel to the optical axis.

17. The method of claim 15, wherein moving the microlens comprises applying an actuation voltage to a driver that is arranged to drive the microlens in the direction perpendicular to the optical axis.

18. The method of claim 15, wherein moving the microlens comprises partially attenuating the signal received by the signal receiver.

19. The method of claim 15, wherein moving the microlens comprises directing the signal away from the signal receiver.

20. The method of claim 15, further comprising suspending the microlens over a substrate on a support member.

21. A method for optical switching using a microlens assembly, comprising:

transmitting a signal through a movable microlens having an optical axis;

moving the microlens in a direction perpendicular to the optical axis between a first position, in which the transmitted signal is directed towards a signal receiver, and at least one other position, in which the transmitted signal is directed at least partially away from the signal receiver; and

suspending the microlens over a substrate on a support member that carries the microlens and is non-integral with the microlens.

22. The method of claim 21, wherein moving the microlens comprises actuating a first drive mechanism that moves the support member in a first direction perpendicular to the optical axis and actuating a second drive mechanism which moves the support member in a second direction opposite the first direction.