Microwave pulse generation with independently tunable pulse width and repetition rate in an actively mode-locked optoelectronic oscillator driven by an amplitude-modulated signal
Bibliographic record
Abstract
An approach to generating microwave pulse trains with independently-tunable pulse width and repetition rate is proposed and demonstrated based on an actively mode-locked optoelectronic oscillator (AML-OEO). In this scheme, an external amplitude-modulated signal, consisting of a carrier frequency and an envelope frequency, is injected into a dual-drive Mach-Zehnder modulator (DDMZM) acting as both the modulation device and the mode-locking device in the cavity. Active mode-locking is established by setting the envelope frequency of the amplitude-modulated signal identical to an integer time of the free spectral range (FSR) in the OEO. Microwave pulses are generated at the temporal positions where the amplitude-modulated signal has the maximum absolute amplitudes. In that regard, a higher carrier frequency equal to an integer multiple of the envelope frequency corresponds to a narrower pulse width. Hence, the pulse width and the repetition rate of the microwave pulse train obtained by AML-OEO can be independently tuned through setting the carrier frequency and the envelope frequency of the amplitude-modulated signal. Both numerical simulation and experiment have been accomplished to verify the feasibility of this method. Experimental results show that microwave pulse trains with a fixed repetition rate of 179.61 kHz and tunable pulse widths in the range of 365 ns to 105 ns are generated. In addition, microwave pulse trains with an identical pulse width of 165 ns and tunable repetition rates in the range of 179.61 kHz and 359.22 kHz are generated. Furthermore, an ultra-short microwave pulse train with a pulse width of 15.7 ns and a repetition rate of 475.468 kHz is obtained, where the pulse width is only 3.94% of that from an AML-OEO driven by a sinusoidal signal under an identical repetition rate. The proposed scheme provides a path to independently control the pulse width and the repetition rate of the microwave pulse train and obtain ultra-short microwave pulse trains in an AML-OEO.
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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 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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 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".