Apparatus for varying the optical characteristics of an optical fiber by stretching the fiber

• US 6,396,994 B1
• Filed: 03/10/2000
• Issued: 05/28/2002
• Est. Priority Date: 03/10/2000
• Status: Expired due to Fees

• Current Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Original Assignee: Viavi Solutions, Inc. (Lumentum Holdings Inc.)
• Inventors: Mala, Mohiuddin, Philipson, Joshua, Lapinski, Feliks
• Primary Examiner(s): Lee, John D.
• Application Number:
  US09/523,101
• Time in Patent Office: 809 Days
• Field of Search: 385/12,13,15,37,134,136,137,147 250/227.14-227.19
• US Class Current: 385/136
• CPC Class Codes: G02B 6/022 using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper G02B6/02204 takes precedence; optical modulation using photo-elastic effect G02F1/0131
• 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 6/3572 Magnetic force magnetic forces controlling reflecting elements in general G02B26/085; magneto-optic devices G02F1/09
• CPC Class Codes: G02B 6/3616 Holders, macro size fixtures for mechanically holding or positioning fibres, e.g. on an optical bench supporting carriers of a microbench type G02B6/3648; micromanipulators B25J7/00; cassettes, bobbins G02B6/4439
• CPC Class Codes: G02F 1/0115 in optical fibres
• CPC Class Codes: G02F 2201/307 Reflective grating, i.e. Bragg grating

Abstract

Apparatus for modifying the optical characteristics of an optical fiber by controlled stretching of a length of the fiber, comprising a first fiber holder fixedly carried by a base and capable of firmly holding a first portion of the optical fiber, a lever part attached to the base at a fulcrum, and second fiber holder movably connected to the lever part and capable of firmly holding a second portion of the fiber, so that an intermediate length of fiber may be held taut between said first and second holding means. An electromagnetic circuit moves the lever part between first and second predetermined positions, so that the intermediate length of fiber is stretched as the lever part moves between first and second positions. Preferably, the intermediate length of fiber includes a Bragg grating.

Claims

1. Apparatus for modifying the optical characteristics of an optical fiber by controlled stretching of a length of the fiber, comprising:

a base;

first fiber holding means fixedly carried by said base and capable of firmly holding a first portion of said optical fiber;

a lever part attached to said base at a fulcrum;

second fiber holding means connected to said lever part and movable therewith, and capable of firmly holding a second portion of said fiber such that an intermediate length of said fiber may be held taut between said first and second holding means;

means for moving the lever part between first and second predetermined positions, so that the intermediate length of fiber is stretched as the lever part moves between first and second positions.

2. Apparatus according to claim 1, wherein said means for moving the lever part are electromagnetic.

3. Apparatus according to claim 1, in combination with a fiber having a Bragg grating, wherein said first and second fiber holding means are located at opposite sides of said Bragg grating.

4. Apparatus according to claim 1 wherein said first and second predetermined positions are determined by stop means on opposite sides of said lever part.

5. Apparatus according to claim 4, wherein the length of said lever part between the fulcrum and the stop means is at least 10 times the distance between the fulcrum and the second fiber holding means.

6. Apparatus according to claim 1, wherein said fulcrum is provided by a flexure which is integral both with the lever part and with a part of said base.

7. Apparatus according to claim 1, wherein said lever part is releasably held in said first or second predetermined positions by magnetic latching means.

8. Apparatus for modifying the optical characteristics of an optical fiber by controlled stretching of a length of the fiber, which length includes a Bragg grating, comprising:

a base;

first fiber holding means fixedly carried by said base and capable of firmly holding a first portion of said optical fiber;

a lever part attached to said base at a fulcrum;

second fiber holding means connected to said lever part and movable therewith, and capable of firmly holding a second portion of said fiber such that an intermediate length of said fiber which incorporates the Bragg grating may be held taut between said first and second holding means;

means for moving the lever part between first and second predetermined positions, so that the intermediate length of fiber is stretched as the lever part moves between first and second positions, and magnetic latching means for releasably holding the lever part in said first or second positions;

and wherein the predetermined positions are provided by adjustable stops on opposite sides of said lever part.

9. Apparatus according to claim 8, wherein the length of said lever part between the fulcrum and the adjustable stops is at least 10 times the distance between the fulcrum and the fiber second holding means.

10. Apparatus according to claim 8, wherein said fulcrum is provided by a flexure which is integral both with the lever part and a part of said base.