Using pulse with a dark base to achieve high spatial and frequency resolution for the distributed Brillouin sensor
Bibliographic record
Abstract
A stimulated Brillouin scattering based distributed optical fiber sensor using a probe pulse (<5 ns) of finite extinction ratio (ER) (>20 dB) followed by a dark base of a finite length is proposed to achieve higher spatial and frequency resolution for the first time. The basic mechanism for detecting the small stress or temperature section is to reduce the peak height of the Brillouin spectrum contributed by dc at the stress point so that the Brillouin frequency shift (BFS) of small stress or temperature section can show up at a much lower peak height of the Brillouin spectrum. The finite ER of the positive pulse is used as prepumping of the phonon field to achieve higher contrast for the Brillouin spectrum. The length of dark base is determined by the balanced contribution of the normal base in fiber and the dark base after the pulse to the Brillouin gain spectrum. The theoretical simulation and the experimental results both demonstrate that the proposed novel pulse shape can be used to measure a centimeter stress or temperature section with small uncertainty for the BFS. For two 5 cm stress sections of 15 MHz equivalent strains in BFS with a 30 cm separation, the measured frequency uncertainty is 0.9 MHz.
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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".