336 Gb/s in Direct Detection Below KP4 FEC Threshold for Intra Data Center Applications
Bibliographic record
Abstract
We demonstrate direct detection of single polarization and dual polarization PAM4 signals delivering 168 and 336 Gb/s below the KP4 FEC threshold of 2.2×10-4. The 84 Gbaud 2 bits and 4 bits per symbol transceivers operate at a bit error rate (BER) that is compliant to the RS(544, 514) FEC encoding for error-free operation, as considered for next generation PAM4 400GBase Ethernet standard targeting data center applications. For the DP-PAM4 format, we show that the BER is independent of the state of polarization of the optical signal. To the best of our knowledge, this is the first experimental demonstration of a single carrier delivering 336 Gb/s in direct detection at a BER compliant to the physical coding sublayer of 400GBASE interfaces. Finally, using an intensity modulator in series with a phase modulator, we demonstrate chromatic dispersion pre-compensation of 84 Gbaud PAM4 signals, producing a 40-fold BER improvement after 10 km of single-mode fiber.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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".