Bibliographic record
Abstract
A computer modelling program has been developed to model the extraction of an ideal 4-level laser system based on the equations of Franz and Nodvik (1963) with the capability of handling realistic temporal shapes of the pump pulse and various overlap geometries of the pump and laser radiation. Two different simulation programs are used to account for different laser pumping geometries. A cylindrical geometry is used for axial pumping, and a Cartesian geometry is used for transverse pumping. In both cases, the laser beams and gain medium are divided into smaller radial and axial zones according to the geometry in use. Absorption of the pump radiation and amplification of output radiation is calculated separately for each cell of the gain medium. Overlap fractions are used to determine the amount of energy from the pump and extraction beams which are present in a particular gain zone. The simulation algorithm calculates absorption and amplification within the gain region for each time step then propagates the laser and pump radiation forward one time step. The fraction of spontaneous emission that propagates along with the laser beam is also amplified but accounted for separately from the laser beam for amplifier systems. The simulation program calculates the spatial and temporal profile of the output pulse energy and accompanying ASE. The geometry assumes collimated or diverging wavefronts for the laser radiation with different beam radii for different passes to allow simulation of expanding beam or unstable resonator geometries. Currently the modelling code is being used to simulate oscillation and short pulse amplification in Ti:sapphire crystals. Initial comparisons with published experimental results show close agreement with the simulation. The ultimate goal will be to model the performance of multistage short pulse amplifier systems.
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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 | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.016 | 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".