Radiometry and Few-photon Metrology at the National Research Council of Canada
Bibliographic record
Abstract
Over the last few years, the National Research Council of Canada (NRC) has been establishing new facilities and improving capabilities in three areas of radiometry: optical power, spectral irradiance, and few-photon measurements. Canada’s realization of the optical radiant power scale now utilizes a new cryogenic electrical substitution radiometer as the primary instrument. With higher cavity absorptance, reduced non-equivalence effects, and a closed-cycle helium cryocooler, this new cryogenic radiometer has significantly contributed to improvements in measurement uncertainties. NRC’s primary spectral irradiance scale has transitioned from a detector based approach to a detector and source based realization. Filter radiometers with spectral responsivity traceable to the cryogenic radiometer and a high temperature blackbody primary light source are implemented in the calibration of transfer standard FEL lamps from 200 nm to 2500 nm. Most recently, NRC has been working to establish a few-photon metrology capability for optical radiometry. The initial goal of this new facility is to measure the detection efficiency of free-space single-photon detectors using a calibrated detector substitution technique. This capability will then be extended to the traceable characterization of NRC on-chip semiconductor quantum dot-based single-photon sources, the evaluation of these sources as new quantum standards, and using entangled photons from these sources for fundamental quantum metrology measurements. Ongoing efforts and details of these new radiometry facilities will be presented.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| 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 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".