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08:48
Writing Bragg Gratings in Multicore Fibers
Published on: April 20, 2016
Analysis of fiber bragg gratings by a side-diffraction interference technique.
Applied Optics
|March 22, 2008
Summary
A novel, non-destructive optical technique accurately measures fiber Bragg grating (FBG) properties and locates faults. This method uses interfering laser beams to precisely determine grating index modulation and period, even for weak gratings.
Area of Science:
- Optics and Photonics
- Materials Science
- Fiber Optic Sensors
Background:
- Fiber Bragg gratings (FBGs) are crucial optical components.
- Accurate characterization of FBG geometry and defects is essential for performance.
- Existing methods may be destructive, non-contact, or lack sensitivity.
Purpose of the Study:
- To present a new nondestructive, noncontact, and sensitive technique for FBG characterization.
- To enable precise measurements of FBG geometry and index-fault locations.
- To facilitate in situ analysis during FBG fabrication.
Main Methods:
- Utilizes two plane-wave probe laser beams incident on the FBG.
- Forms an interference pattern from diffracted and transmitted beams.
- Analyzes fringe visibility and period to determine index modulation and grating period.
Main Results:
- Achieved high accuracy: 1 x 10(-4) for index modulation and 0.01 nm for period.
- Demonstrated sensitivity for weak gratings.
- Successfully analyzed both unchirped and chirped FBGs.
Conclusions:
- The proposed technique offers a sensitive, nondestructive, and noncontact method for FBG analysis.
- It is valuable for both post-fabrication analysis and in situ monitoring during manufacturing.
- This method enhances quality control and fabrication process understanding for FBGs.
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