Wavelength-tunable devices and systems comprising flexed optical gratings

• US 6,154,590 A
• Filed: 09/28/1998
• Issued: 11/28/2000
• Est. Priority Date: 09/28/1998
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Jin, Sungho, Mavoori, Hareesh
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US09/162,325
• Time in Patent Office: 792 Days
• Field of Search: 385/37, 385/6, 385/12, 385/19, 385/16, 385/31, 385/137, 372/20, 372/64, 359/115, 359/124, 359/130, 359/341
• US Class Current: 385/37
• 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

Abstract

In accordance with the invention, a tunable optical grating device comprises a grating, which is fixed at both ends to a support frame and is flexed so that a tensile strain induced in the grating reconfigures the resonant wavelength. Typical embodiments include mechanical or magnetic latching arrangements capable of inducing a latchable change in grating periodicity. In typical embodiments programmable and latchable magnets accurately produce a predetermined amount of fiber deflection and tensile strain, thereby producing a latchable wavelength shift with minimal power. The device is especially useful in WDM communication systems for adding or dropping channels, for dynamically gain-equalizing optical amplifiers, for tuning lasers, and for dispersion compensation.

Claims

1. A wavelength-tunable grating device comprising:

a support frame for supporting a body of material;

a body of material including an optical grating, the body attached to the support frame on opposite sides of the grating; and

a movable body for pushing of pulling laterally on the body or material to elastically flex the body and induce a tensile strain therein, thereby altering the resonant resonant wavelength of the grating.

2. The device of claim 1 wherein the movable body is magnetic and including a programmable magnet for moving the magnetic movable body.

3. The device of claim 2 wherein the programmable magnet is latchable.

4. The device of claim 3 wherein the magnetization latching of the programmable magnet after the applied field is removed, is at least 80% of the magnetization when the field is on.

5. The device of claim 1 wherein said body comprises a length of optical waveguide.

6. The device of to claim 5 wherein said grating is a long-period grating.

7. The device of claim 1 including means for mechanically moving the movable body.

8. The device of claim 1 wherein said movable body is latchable.

9. The device of claim 1 including means for magnetically moving the movable body.

10. The device of claim 1 wherein the said device is bistable with a switching capability between two strain states.

11. The device of claim 1 wherein said grating is a Bragg grating.

12. A device of to claim 1 wherein said grating is a diffraction grating.

13. The device of claim 1 wherein the movable body includes an elastically deformable surface.

14. The device of claim 1 wherein said body comprises an optical fiber.

15. The grating device of claim 1 wherein said grating is chirped grating.

16. The device according to claim 1 including a tweaking mechanism for adjusting the wavelength of the grating after fabrication.

17. An optical multiplexer/demultiplexer comprising an optical grating device according to claim 1.

18. An optical waveguide amplifier comprising a long period optical grating device according to claim 1.