High-efficiency off-chip grating couplers for silicon nitride photonics
Bibliographic record
Abstract
Silicon nitride (Si3N4) is a leading platform in integrated photonics, providing unique passive functionalities, while maintaining compatibility with complementary metal-oxide-semiconductor processes and scalable and low-cost high-volume production. However, the moderate index contrast of the Si3N4 platform makes it difficult to implement efficient vertical surface grating couplers. In this work, we present efficient and robust fiber-chip grating couplers on native and hybrid Si3N4 platforms. Minimum coupling losses between -5 dB and -3 dB were measured for single-etch fabricated devices near 1.55 μm wavelength. Moreover, by leveraging the amorphous-silicon overlay on top of the Si3N4 platform, we develop hybrid single-etch grating couplers, with a coupling loss approaching 1 dB. The demonstrated grating couplers are promising for SiN integrated photonics, enabling a rapid and cost-effective chip interfacing with standard optical fibers. This opens up novel opportunities for rising applications, including optical communications, nonlinear optics, or quantum information sciences.
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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) | 0.000 | 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) | 0.001 | 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".