Optical switching and attenuation systems and methods therefor

• US 6,404,969 B1
• Filed: 03/30/1999
• Issued: 06/11/2002
• Est. Priority Date: 03/30/1999
• Status: Expired due to Term

• Current Assignee: RPX Clearinghouse LLC (RPX Corporation)
• Original Assignee: Coretek, Inc. (Nortel Networks Corporation)
• Inventors: Tayebati, Parviz, Azimi, Masud, Vakhshoori, Daryoosh
• Primary Examiner(s): Phan, James
• Application Number:
  US09/281,406
• Time in Patent Office: 1,169 Days
• Field of Search: 385/140, 385/18, 359/223, 359/224, 359/198-199, 359/212, 359/230
• US Class Current: 385/140
• CPC Class Codes: G02B 6/3502 involving direct waveguide displacement, e.g. cantilever type waveguide displacement involving waveguide bending, or displacing an interposed waveguide between stationary waveguides
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• 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 6/353 the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3544 2D constellations, i.e. with switching elements and switched beams located in a plane
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• 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 6/3566 involving bending a beam, e.g. with cantilever
• CPC Class Codes: G02B 6/3568 characterised by the actuating force
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• 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 6/3584 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 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams

Abstract

Novel light switches and attenuators are disclosed. In one form of the invention, a novel 2×2 crossbar switch is formed by positioning a movable reflector intermediate four fiberoptic lines. In another form of the invention, a 1×N switch is formed by providing a plurality of cantilevers each having a reflective surface thereon. In still another form of the invention, a novel light attenuator is formed by positioning a movable arm intermediate two fiberoptic elements.

Claims

1. In combination with a pair of fiber optic lines arranged for transmission of light from the end of one line to the end of the other line according to a predetermined light path, an optical attenuator for attenuating light passing from said one line to said other line, said optical attenuator comprising:

a support; and

a microelectromechanical structure carried by said support, said microelectromechanical structure comprising (a) a cantilever arm having one end that is fixed relative to said support and an opposite end that extends transversely to said light path and is free to move relative to said support and said light path, (b) a mirror attached to said opposite end of said arm, said mirror being attached solely to said arm, and (c) electrically operable means for moving said arm so as to cause said opposite end and said mirror to swing in an arc relative to said support, said arm being disposed so that it extends at a right angle to said light path and said electrically operable means being operable to move said arm in said arc so as to move said mirror into and out of said light path to selectively attenuate transmission of light passing from one fiber optic line toward the other fiber optic line.

2. The combination according to claim 1 wherein said fiber optic lines are disposed in end-to-end aligned relation with one another with a space therebetween.

3. The combination according to claim 1 wherein said support is disposed between said fiber optic lines.

4. The combination according to claim 1 wherein said support has an aperture located between adjacent ends of said fiber optic lines, whereby to facilitate transmission of light from the end of one fiber optic line to the adjacent end of the other fiber optic line.

5. The combination according to claim 1 wherein said support has an antireflection coating to prevent reflections of light therefrom.

6. The combination according to claim 1 wherein said electrically operated means is a comb drive.

7. The combination according to claim 1 wherein said electrically operated means moves said arm and mirror in a plane that extends perpendicular to said light path, and said mirror is disposed at an angle to said plane so that it will not reflect light back to said one fiber optic line.

8. An optical attenuator comprising:

a support;

an arm having first and second opposite ends with said first end being secured to said support;

a mirror attached to said second end of said arm, said mirror being supported solely by said arm; and

microelectromechanical means for moving said second end of said arm so as to selectively position said mirror across a light path extending between two light transmitting elements, whereby said mirror will intercept and reflect light traveling along said light path, wherein said microelectromechanical means is a comb drive.