Flattop Efficient Cascaded χ$^{\bf {\bm (}2{\bm)}}$ (SFG + DFG)-Based Wideband Wavelength Converters Using Step-Chirped Gratings
Bibliographic record
Abstract
We numerically evaluate efficient wideband wavelength converters based on quasi-phase-matched cascaded sum and difference frequency generation (SFG + DFG) using step-chirped gratings (SCG) in lossy lithium niobate waveguides, and compare them to the ones using uniform gratings, assuming a large pump wavelength difference considering a full model of depleted pump and sum-frequency waves. For the same length, appropriate critical period shifts are presented for the number of sections and chirp steps to achieve flattop conversion efficiency responses with peak-to-peak ripples less than 0.2 dB. To obtain the maximum efficiency and flat response with a decreasing chirp step of 1 nm, the criteria for the design of optimum four-section single-pass and two-section double-pass SCG-based devices, including the assignment of length (to achieve a desired bandwidth) and pump power, are presented considering a 75-nm pump wavelength difference. Also, the performances of single-pass and double-pass schemes for the two- and four-section SCG-based devices are given, respectively, and compared to those of uniform grating-based devices with and without pump detuning, assuming a 3-cm-long waveguide and 50-mW input pump powers. For the same length and power, using the SCG with fixed pumps instead of the uniform grating with detuned pumps shows a noteworthy increase in the mean efficiency to attain almost the same response flatness and bandwidth.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 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".