20 W at 589 nm via frequency doubling of coherently beam combined 2-MHz 1178-nm CW signals amplified in Raman PM fiber amplifiers
Bibliographic record
Abstract
The authors report the recent breakthroughs of our research activities carried out in the framework of the ESO R&D programs to develop 589-nm CW sources for laser guide stars (LGS). Large telescopes equipped with adaptive optics require 20-25 W 589-nm CW light sources with an emission linewidth < 50 MHz. Towards this goal, we have been working on the development of high-power narrowband 1178-nm Raman fiber lasers with subsequent frequency doubling to 589 nm. Fiber lasers are an asset and probably the best laser type in remote and difficult operation sites like astronomical observatories. Typically, they are compact, maintenance-free, turn-key, ruggedized devices. Moreover their output beam quality is excellent, an important requirement for LGS.
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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) | 0.001 | 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 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".