Characterization of the Birefringence in Fiber Bragg Gratings Fabricated With an Ultrafast-Infrared Laser
Bibliographic record
Abstract
<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The changes of birefringence in Type I-infrared (Type I-IR) and Type II-IR fiber Bragg gratings induced by an ultrafast-IR laser in SMF-28 fibers are examined after and/or during grating inscription. The gratings are then annealed at increased temperatures up to 800 <formula formulatype="inline"><tex>$^{\circ}\hbox{C}$</tex></formula>, and their polarization properties are monitored. It is shown that the birefringence in Type I-IR gratings inscribed in hydrogen <formula formulatype="inline"><tex>$(\hbox{H}_{2})$</tex></formula>-loaded fibers is small <formula formulatype="inline"><tex>$(\sim{\kern-2pt}10^{-6})$</tex></formula> and can be decayed at room temperature, while the birefringence in Type I-IR gratings inscribed in non-<formula formulatype="inline"><tex>$ \hbox{H}_{2}$</tex></formula>-loaded fibers is relatively higher <formula formulatype="inline"><tex>$(\sim{ \kern-2pt}10^{ - 5})$</tex></formula> and shows strong dependence on the polarization of the IR laser beam. It has the same annealing resistance as the induced index. For Type II-IR gratings, the birefringence is an order of magnitude higher than in Type I-IR gratings <formula formulatype="inline"><tex>$(\sim{\kern-2pt}10^{ - 4})$</tex> </formula> and shows strong temperature variation during annealing. </para>
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".