Bibliographic record
Abstract
Pump-probe spectroscopy of molecular systems requires high average power, short pulse, mid-infrared sources. Today OPO deliver wavelengths up to 4 µm and THz systems supply wavelengths beyond 20 µm. To achieve tunable wavelengths in between these two regions, the signal and idler beams of the OPO can be difference frequency mixed again. This two-step nonlinear process necessarily leads to average power much less than the OPO pump, which is typically a 1 W Ti:sapphire laser. In this paper, we report initial experimental results of two-wavelength amplification in a Yb-doped DCF fiber. Yb:fibre amplifiers have been shown to deliver short pulses at average power levels of up to 20 W[1] .The goal of the work is to generate high average power (<1W) pump and signal beams for difference frequency generation at around 15 µm. A schematic of the experimental is shown in Fig.1. A photonics crystal fiber is pumped by a mode-locked Ti:Sapphire laser to create supercontinuum, from which we can select the two seed wavelengths by using a standard zero dispersion grating line that has been adapted to have individual mirrors in the focal plane for the two different colours. The Yb:fibre is pumped by a 915nm diode laser. As shown in Fig. 2, at a pump power of 2.1 W, 500 gain was achieved yielding 150 mW total power(1055 and 1095 nm). References:1. D. Nickel et al, Opt. Commun. 190, 309 (2001)
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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 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.007 | 0.003 |
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".