Claims
- 1. A method for manufacturing an optical waveguide refractive index grating having a desired grating pitch Λ, the method comprising the steps of:
providing a photosensitive waveguide; providing a writing beam of actinic radiation, the writing beam having an intensity; translating the waveguide relative to the writing beam at a velocity v(t); modulating the intensity of the writing beam as a function of time at a frequency f(t), wherein 17v(t)f(t)≈Λ;the step of modulating the intensity of the writing beam as a function of time at a frequency f(t) comprising the step of varying Λ.
- 2. The method of claim 1, including the steps of translating a chirped phase mask through the writing beam to create an interferogram of a changing period Λ(t), where
- 3. The method of claim 1, the step of providing a writing beam comprising providing a writing beam having a peak intensity illuminating the fiber I0 and a width D, wherein the fluence Φ(x) delivered to the waveguide is determined by the equation
- 4. The method of claim 1, wherein the varying-period interferogram is produced using a tunable interferometer.
- 5. A long-length phase continuous Bragg grating manufactured in accordance with the method of claim 1.
- 6. The grating of claim 5, the grating having a length of at least 2.5 meters.
- 7. The grating of claim 5, wherein the grating has a length of at least four meters.
- 8. The grating of claim 5, wherein the grating is a continuous phase Bragg grating.
- 9. The grating of claim 5, wherein the waveguide is a photosensitive optical fiber and the grating is a continuous refractive index perturbation.
- 10. The grating of claim 5, wherein the index perturbation has a changing periodicity along the length of the grating.
- 11. The grating of claim 5, wherein the step of translating included placing the waveguide on a rotary stage.
- 12. The grating of claim 5, where in the grating is chirped.
- 13. An optical dispersion compensator comprising the grating of claim 5.
- 14. A broadband light generator comprising the grating of claim 5.
- 15. A rapid spectral interrogator comprising the grating of claim 5.
- 16. A sensor comprising the grating of claim 5.
- 17. A method for writing a refractive index grating having a desired grating pitch Λ on an optical waveguide, the method comprising the steps of:
providing a writirg beam of actinic radiation; translating the waveguide relative to the writing beam at a velocity v(t); modulating the intensity of the writing beam as a function of time at a frequency f(t), wherein 21v(t)f(t)≈Λ; the step of modulating the intensity of the writing beam as a function of time at a frequency f(t) comprising the step of varying Λ.
- 18. A grating manufactured in accordance with the method of claim 17.
RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S. application Ser. No. 09/161,944, entitled “Long-Length Continuous Phase Bragg Reflectors In Optical Media”, filed Sep. 28, 1998, which is a continuation-in-part of U.S. application Ser. No. 08/942,590, issued as U.S. Pat. No. 5,912,999, entitled “Method For Fabrication Of In-Line Optical Waveguide Refractive Index Gratings Of Any Length”, filed Oct. 2, 1997, both of which are incorporated herein by reference.
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
09161944 |
Sep 1998 |
US |
Child |
10066524 |
Jan 2002 |
US |
Parent |
08942590 |
Oct 1997 |
US |
Child |
09161944 |
Sep 1998 |
US |