The impact of laterally coupled grating microstructure on effective coupling coefficients
Bibliographic record
Abstract
Lithographic fabrication may be used to define laterally coupled gratings of high refractive index contrast on waveguide ridges, eliminating the need for regrowth steps in such distributed feedback lasers. These may be made more amenable to fabrication by employing higher-order gratings. Reliable exploration of the laser design space requires that the radiating partial waves be accurately incorporated in numerical simulations. We modify the coupled-mode approach to fully consider the two-dimensional cross section, analyzing rectangular, sinusoidal, triangular and trapezoidal grating shapes. Effective coupling coefficients are determined for grating orders from first to third. We show that, by tailoring the grating microstructure, effective coupling coefficients up to double that of a 0.5 duty cycle rectangular grating can be achieved. The actual grating microstructure of an as-fabricated grating was analyzed and its effective coupling coefficient predicted as [Formula: see text]. This was found to be in excellent agreement with the value extracted from the amplified spontaneous emission spectrum, [Formula: see text].
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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 | 0.001 |
| 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".