Optical microswitch

• US 6,836,584 B1
• Filed: 03/14/2000
• Issued: 12/28/2004
• Est. Priority Date: 01/13/1998
• Status: Expired due to Term

• Current Assignee: Coherent Inc (Coherent Corp.)
• Original Assignee: iolon, Inc. (Coherent Corp.)
• Inventors: Petersen, Kurt E., Jerman, John H., Grade, John D., Drake, Joseph D.
• Primary Examiner(s): Lee, John D.
• Assistant Examiner(s): PAK, SUNG H
• Application Number:
  US09/524,727
• Time in Patent Office: 1,750 Days
• Field of Search: 385/18, 385/19, 385/25, 359/223
• US Class Current: 385/18
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• 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 6/3548 1xN switch, i.e. one input and a selectable single output of N possible outputs
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3582 Housing means or package or arranging details of the switching elements, e.g. for thermal isolation
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/4216 incorporating polarisation-maintaining fibres polarisation-maintaining fibres per se G02B6/105
• CPC Class Codes: G11B 11/10543 using optical beam of radiation
• CPC Class Codes: G11B 11/1058 Flying heads
• CPC Class Codes: G11B 7/0037 with discs
• CPC Class Codes: G11B 7/08564 using galvanomirrors
• CPC Class Codes: G11B 7/122 Flying-type heads, e.g. analogous to Winchester type in magnetic recording
• CPC Class Codes: G11B 7/1362 Mirrors
• CPC Class Codes: G11B 7/1384 Fibre optics
• CPC Class Codes: H02N 1/008 Laterally driven motors, e.g. of the comb-drive type

Abstract

An optical microswitch for use with a laser beam that extends along a path comprising a body having an inlet port adapted to receive the laser beam and a plurality of outlet ports. A plurality of mirrors coupled to a plurality of micromotors carried by the body. The micromotors selectively move the mirrors from a first position out of the path of the laser beam to a second position into the path of the laser beam to direct the laser beam to one of the outlet ports. Each of the micromotors has at least one electrostatically-driven comb drive assembly therein for moving the respective mirror to one of the first and second positions. A controller is electrically coupled to the micromotors for providing control signals to the micromotors.

Claims

1. An optical microswitch for use with a laser beam that extends along a path comprising a body having an inlet port adapted to receive the laser beam and a plurality of outlet ports, a plurality of mirrors carried by the body, a plurality of micromotors carried by the body, microattachment means for rigidly coupling the plurality of mirrors to the respective plurality of micromotors whereby the micromotors selectively move the mirrors from a first position out of the path of the laser beam to a second position into the path of the laser beam to direct the laser beam to one of the outlet ports, each of the micromotors having at least one electrostatically-driven comb drive assembly therein for moving the respective mirror to one of the first and second positions, and a controller electrically coupled to the micromotors for providing control signals to the micromotors.

2. An optical microswitch as in claim 1 wherein the plurality of mirrors and plurality of micromotors include a first plurality of mirrors and corresponding micromotors and a second plurality of mirrors and corresponding micromotors, the path of the laser beam extendable between the first plurality of micromotors and the second plurality of micromotors so that the first plurality of micromotors oppose the second plurality of micromotors relative to the path of the laser beam.

3. An optical microswitch as in claim 2 wherein the first plurality of mirrors and corresponding micromotors are linearly disposed along a first imaginary line and the second plurality of mirrors and corresponding micromotors are linearly disposed along a second imaginary line extending parallel to the first imaginary line and the path of the laser beam.

4. An optical microswitch as in claim 2 wherein the first plurality of micromotors includes at least two micromotors disposed side by side along a first imaginary line extending perpendicularly of the path of the laser beam and the second plurality of micromotors includes at least two micromotors disposed side by side along a second imaginary line extending perpendicularly of the path of the laser beam.

5. An optical microswitch as in claim 2 wherein the first and second plurality of mirrors are each inclined to direct the laser beam in a single direction.

6. An optical microswitch as in claim 2 wherein the plurality of mirrors and plurality of micromotors include a third plurality of mirrors and corresponding micromotors and a fourth plurality of mirrors and corresponding micromotors, the path of the laser beam extendable between the third plurality of micromotors and the fourth plurality of micromotors so that the third plurality of micromotors oppose the fourth plurality of micromotors relative to the path of the laser beam, means including an additional mirror and corresponding additional micromotor for selectively directing the laser beam along a first path extending between the first and second plurality of micromotors and a second path extending between the third and fourth plurality of micromotors.

7. An optical microswitch as in claim 6 wherein the first and second plurality of mirrors and the third and fourth plurality of mirrors are inclined to direct the laser beam in a single direction.

8. An optical microswitch as in claim 1 wherein the plurality of mirrors and plurality of micromotors include at least one first mirror and corresponding first micromotor and at least one second mirror and corresponding second micromotor, the path of the laser beam extendable between the at least one first micromotor and the at least one second micromotor so that the at least one first micromotor opposes the at least one second micromotor relative to the path of the laser beam and wherein the plurality of mirrors and plurality of micromotors further include at least one third mirror and corresponding third micromotor and at least one fourth mirror and corresponding fourth micromotor, the path of the laser beam extendable between the at least one third micromotor and the at least one fourth micromotor so that the at least one third micromotor opposes the at least one fourth micromotor relative to the path of the laser beam, means including an additional mirror and corresponding additional micromotor for selectively directing the laser beam along a first path extending between the at least one first micromotor and the at least one second micromotors and a second path extending between the at least one third micromotor and the at least one fourth micromotor.

9. An optical microswitch as in claim 1 wherein the plurality of micromotors includes a plurality of at least two micromotors disposed side by side along an imaginary line extending perpendicularly of the path of the laser beam.

10. An optical microswitch as in claim 1 wherein a plurality of at least twelve mirrors and corresponding micromotors are provided for selectively directing the laser beam in a plurality of parallel directions.

11. An optical microswitch as in claim 1 wherein each mirror comprises a layer of silicon and a layer of a reflective material adhered to the layer of silicon whereby the layer of silicon provides a surface of low roughness and high flatness.

12. An optical microswitch as in claim 11 wherein each mirror further comprises at least one pair of dielectric layers overlying the layer of a reflective material, said at least one pair of dielectric layers including a first layer of a low dielectric material and a second layer of a high dielectric material.

13. An optical microswitch as in claim 1 wherein at least one of the micromotors includes travel stop means for limiting the movement of the corresponding mirror at the second position whereby the travel stop means facilitates repeatability in the operation of the optical microswitch.

14. An optical microswitch as in claim 13 further comprising lead means for electrically connecting the travel stop means to the controller whereby the travel stop means permits the controller to monitor when the mirror is in the second position.

15. An optical microapparatus for use with a laser beam that extends along a path comprising a body having an inlet port adapted to receive the laser beam and a plurality of outlet ports, a plurality of reflectors carried by the body, a plurality of micromotors carried by the body, each of the micromotors having at least one electrostatically-driven comb drive assembly, microattachment means for rigidly coupling the plurality of reflectors to the respective plurality of micromotors and a controller electrically coupled to the micromotors for providing control signals to the micromotors whereby each of the micromotors selectively moves the respective reflector from a first position out of the path of the laser beam to a second position into the path of the laser beam for directing light from the laser beam to an outlet port.

16. An optical microapparatus as in claim 15 wherein the plurality of reflectors and plurality of micromotors include a first plurality of reflectors and corresponding micromotors and a second plurality of reflectors and corresponding micromotors, the first plurality of micromotors opposing the second plurality of micromotors relative to the path of the laser beam so that the path of the laser beam extends between the first plurality of micromotors and the second plurality of micromotors.

17. An optical microapparatus as in claim 15 wherein each reflector comprises a layer of silicon and a layer of a reflective material adhered to the layer of silicon.

18. An optical microapparatus as in claim 15 wherein each reflector comprises a planar substrate, a reflective layer disposed over the planar substrate and at least one optically transparent quarter-wavelength thin film disposed over the reflective layer.

19. An optical microapparatus as in claim 18 wherein the reflective layer includes a gold layer.

20. An optical microapparatus as in claim 18 wherein the reflective layer includes an aluminum layer.

21. An optical microapparatus as in claim 18 further comprising an adhesion layer disposed between the reflective layer and the planar substrate for securing the reflective layer to the planar substrate.

22. An optical microapparatus as in claim 21 wherein the adhesion layer is made of chromium.

23. An optical microapparatus as in claim 18 wherein the at least one optically transparent quarter-wavelength thin film includes a quarter-wavelength silicon dioxide thin film.

24. An optical microapparatus as in claim 15 wherein each reflector comprises a planar substrate, a reflective layer, means for securing the reflective layer to the planar substrate, a first dielectric layer of a material having a relatively low index of refraction overlying the reflective layer and a second dielectric layer of a material having a relatively high index of refraction overlying the first dielectric layer for increasing the reflectivity of the micromachined reflector.

25. An optical microapparatus as in claim 24 for use with laser light having a wavelength wherein the first dielectric layer and the second dielectric layer each have an optical thickness equal to one-quarter the wavelength of the laser beam.

26. An optical microapparatus as in claim 24 wherein the first dielectric layer is a material selected from the group consisting of magnesium fluoride and silicon dioxide.

27. An optical microapparatus as in claim 24 wherein the second dielectric layer is a material selected from the group consisting of cerium oxide and titanium.

28. An optical microapparatus as in claim 24 wherein the reflective layer is a material selected from the group consisting of gold, silver and aluminum.

29. An optical microapparatus as in claim 24 wherein the means for securing the reflective layer to the planar substrate is an adhesion layer.

30. An optical microapparatus as in claim 29 wherein the adhesion layer is a material selected from the group consisting of chromium and titanium.

31. An optical microapparatus as in claim 24 further comprising an additional first dielectric layer of a material having a relatively low index of refraction overlying the second dielectric layer and an additional second dielectric layer of a material having a relatively high index of refraction overlying the additional first dielectric layer.