Jitter reduction of the 729 nm clock laser for a Ca+ optical frequency standard
Why this work is in the frame
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Bibliographic record
Abstract
The electric quadrupole transition between the ground state and the first metastable state of a single Ca ion is an attractive choice for a frequency standard in the optical domain. Probing of the clock transition is carried out using quantum jump statistics which requires cycle times of several seconds. The spectral linewidth of the probe laser (local oscillator) must reach the hertz level for a duration at least as long as these cycle times. To reduce the TiSa laser linewidth at 729 nm, we use a KD*P electro-optic modulator (EOM) inside the laser cavity. This device shows a couple of mechanical resonances induced by piezo-electric ringing at frequencies larger than 50 kHz, limiting notably the use of the device for frequency corrections. Actual performances (Delta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">v</sub> < 1 kHz for tau < 1 ms) of our laser set-up allow the observation of a preliminary spectrum with Zeeman splitting of the 729 nm transition of a single trapped Ca <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ion.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 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 it