First Demonstration of Type-A Femtosecond-Written Volume Bragg Gratings using a Gaussian-Bessel Laser Beam
Bibliographic record
Abstract
In the past decades, Volume Bragg gratings (VBGs) have been extensively used in many applications. So far, they have been commonly inscribed in photo-thermo-refractive glasses using UV light [1]. Moreover, femtosecond (fs) direct laser writing (DLW) has been employed to obtain VBGs in other materials supported mainly by type-1 refractive-index modifications (An) [2]. Thanks to this approach, there is therefore an evergrowing interest for writing VBGs in new types of glasses capable of generating stronger refractive-index modifications like silver-containing phosphate glasses. These glasses have a distinct modification type referred to as Type A (A for Argentum), related to the spatial distribution of the generated silver clusters around the interaction voxel showing two positive Δn peaks for every laser pass [3], allowing to reach Δn values of up to 2*10-<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> [4].
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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 | 0.000 |
| 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".