Simple fiber optic refractive index sensor based on evanescent higher order modes
Bibliographic record
Abstract
This paper presents an optical fiber refractive index sensor based on the evanescent higher order modes. Its structure and principle are quite simple. The sensor is composed of two segments of optical fibers that are spliced together. An ordinary multimode fiber with a core diameter of 50 μm is used to input the light. The functions of a second multimode fiber with a core diameter of 200 μm are twofold. In the region of the splice, a section of the cladding a few centimetre long is removed by an electrical discharge. This part works as a sensing element, and the rest of the fiber is used to output the light. Once the light travels though the input fiber and crosses the splice to enter the second fiber, numerous modes both guided and leaky are generated due to the abrupt increase of the core diameter. The evanescent light fields of these guided modes are sensitive to changes in the refractive index of the material surrounding the fiber cladding. The evanescent field change directly causes a change in the output light intensity. The developed sensor is compact in size, simple to fabricate, promising in performance, and has a high potential for practical applications.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".