Optical data storage system having optical microswitch

• US 6,134,207 A
• Filed: 08/17/1998
• Issued: 10/17/2000
• Est. Priority Date: 07/30/1996
• Status: Expired due to Term

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology plc (Seagate Technology Holdings Plc)
• Inventors: Petersen, Kurt E., Jerman, John H., Grade, John D., Drake, Joseph D.
• Primary Examiner(s): HINDI, NABIL Z
• Application Number:
  US09/135,236
• Time in Patent Office: 792 Days
• Field of Search: 369/44.12, 369/44.14, 369/112, 369/44.23, 369/44.24, 369/120, 369/118
• US Class Current: 369/112.29
• 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 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/0866 the reflecting means being moved or deformed by thermal means
• CPC Class Codes: G02B 6/3514 the reflective optical element moving along a line so as to translate into and out of the beam path, i.e. across the beam path
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• 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 11/10554 the transducers being disposed on the same side of the carrier flying heads G11B11/1058
• CPC Class Codes: G11B 11/10563 Access of indexed parts
• 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 data storage system comprising an input light-carrying element providing a laser beam, an optical microswitch, a plurality of output light-carrying elements, a plurality of flying heads and a plurality of optical discs having respective surfaces, each of the flying heads being movable over one of the optical disc surfaces and one of the output light-carrying elements being coupled to each of the flying heads, the optical microswitch selectively directing the laser beam to one of the output light-carrying elements.

2. An optical data storage system as in claim 1 for use with a laser beam that extends along a path wherein the optical microswitch includes a body having an inlet port 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, attachment means for 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.

3. An optical data storage system as in claim 2 wherein the plurality of optical discs are a plurality of magneto-optical discs.

4. An optical data storage system as in claim 3 wherein the plurality of magneto-optical discs includes a stack of magneto-optical discs, each of the magneto-optical discs having at least one magneto-optical disc surface.

5. An optical data storage system as in claim 3 in which the laser beam is reflected by the surface of one of the magneto-optical discs to produce a reflected laser beam having a polarization rotation, further comprising an optical microassembly carried by the body for measuring the polarization rotation of the reflected laser beam.

6. An optical data storage system as in claim 2 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.

7. An optical data storage system as in claim 6 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.

8. An optical data storage system as in claim 6 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.

9. An optical data storage system as in claim 6 wherein the first and second plurality of mirrors are each inclined to direct the laser beam in a single direction.

10. An optical data storage system as in claim 6 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.

11. An optical data storage system as in claim 10 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.

12. An optical data storage system 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 micromotor and a second path extending between the at least one third micromotor and the at least one fourth micromotor.

13. An optical data storage system as in claim 2 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.

14. An optical data storage system as in claim 2 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.

15. An optical data storage system as in claim 2 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.

16. An optical data storage system as in claim 15 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.

17. An optical data storage system as in claim 2 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.

18. An optical data storage system as in claim 17 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.

19. An optical data storage system as in claim 1 wherein the input light-carrying element provides a laser beam that extends along a path and wherein the optical microswitch includes a body, at least one mirror carried by the body and at least one micromotor carried by the body and coupled to the at least one mirror, the input light-carrying element and the plurality of output light-carrying elements being coupled to the body, whereby the at least one micromotor selectively moves the at least one mirror 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 output light-carrying elements.

20. An optical data storage system as in claim 19 wherein the at least one micromotor has at least one electrostatically-driven comb drive assembly therein for moving the at least one mirror to one of the first and second positions.

21. An optical data storage system as in claim 1 wherein the plurality of output light carrying elements comprise optical fibers.

22. An optical data storage system as in claim 1 wherein the plurality of output light carrying elements comprise polarization maintaining optical fibers.

23. An optical data storage system as in claim 1 wherein the plurality of optical disc surfaces comprise magneto-optical disc surfaces.

24. An optical data storage system as in claim 1 wherein the input light-carrying element provides a laser beam that extends along a path and wherein the optical microswitch includes a body, at least one mirror carried by the body and at least one micromotor carried by the body and coupled to the at least one mirror, the input light-carrying element and the plurality of output light-carrying elements being coupled to the body, whereby the at least one micromotor selectively moves the at least one mirror in the path of the laser beam to direct the laser beam to one of the output light carrying elements.

25. An optical data storage system comprising a laser source providing a laser beam, an optical microswitch, a plurality of output light-carrying elements, a plurality of flying heads and a plurality of optical disc surfaces, each of the flying heads being movable over one of the optical disc surfaces and one of the output light-carrying elements being coupled to each of the flying heads, the optical microswitch selectively directing the laser beam between the laser source and the output light-carrying elements.

26. An optical data storage system as in claim 25 wherein the laser source provides a laser beam that extends along a path and wherein the optical microswitch includes a body, at least one mirror carried by the body and at least one micromotor carried by the body and coupled to the at least one mirror, the plurality of output light-carrying elements being coupled to the body, whereby the at least one micromotor selectively moves the at least one mirror in the path of the laser beam to selectively direct the laser beam between the laser source and the output light-carrying elements.

27. An optical data storage system as in claim 25 for use with a laser beam that extends along a path wherein the optical microswitch includes a body having a plurality of outlets, a plurality of mirrors carried by the body, means coupled to each of the mirrors for electrostatically driving the mirror between a first position out of the path of the laser beam to a second position into the path of the laser beam to selectively direct the laser beam to one of the outlets and a controller electrically coupled to said means for providing electrical control signals to said means.

28. An optical data storage system as in claim 25 for use with a laser beam that extends along a path wherein the optical microswitch includes a body having a plurality of outlets, a plurality of mirrors carried by the body and an electrostatic actuator coupled to each of the mirrors for moving the mirror in a linear direction between a first position out of the path of the laser beam to a second position into the path of the laser beam to selectively direct the laser beam to one of the outlets.

29. An optical data storage system as in claim 28 wherein the electrostatic actuator is capable of moving the mirror in a linear direction a distance ranging from at least approximately 100 to 200 microns between the first and second positions.

30. An optical data storage system comprising a laser source providing a laser beam that extends along a path, an optical microswitch, a plurality of output light-carrying elements, a plurality of flying heads and a plurality of optical disc surfaces, each of the flying heads being movable over one of the optical disc surfaces and one of the output light-carrying elements being coupled to each of the flying heads, the optical microswitch having a body and at least one mirror and at least one electrostatic actuator carried by the body, the plurality of output light-carrying elements being coupled to the body and the at least one electrostatic actuator being coupled to the at least one mirror for selectively moving the at least one mirror from a first position out of the path of the laser beam to a second position in the path of the laser beam so as to direct the laser beam to one of the output light-carrying elements.

31. An optical data storage system as in claim 30 wherein the at least one electrostatic actuator is an electrostatic linear actuator for selectively moving the at least one mirror in a linear direction from a first position out of the path of the laser beam to a second position in the path of the laser beam.

32. An optical data storage system as in claim 31 wherein the at least one electrostatic linear actuator includes a comb drive assembly.

33. An optical data storage system as in claim 31 wherein the at least one electrostatic linear actuator includes a comb drive assembly having a plurality of comb drive fingers.

34. An optical data storage system as in claim 31 wherein the at least one electrostatic linear actuator is an actuator capable of moving the at least one mirror in a linear direction a distance ranging from at least approximately 100 to 200 microns from the first position to the second position.