Bibliographic record
Abstract
Our team has an on-going quantum satellite network project in Canada called Quantum Encryption and Science Satellite (QEYSSat). I would like to introduce our polarization-based entangled photon source suitable for the satellite QKD. The idea of satellite based QKD came up to overcome the technical limitation of using fibers. We are aiming for our quantum source to sufficiently overcome the current distance limits. In order to achieve, my quantum source will have to meet the following three criteria; high pair production rate, narrow bandwidth of wavelengths and high stability. We require the minimum pair production rate for the satellite communication to be above 100 MHz (meaning 100 million photon pairs per second). Meanwhile, most telecommunication through the ground these days uses optical fibers which transports signals with 1550nm or 1310nm wavelengths. We have specifically chosen 791nm signal wavelength which can have 1550nm idler wavelength as its pair. Another focus was bandwidths of the photon wavelengths. A broad photon wavelength will require a large bandwidth filter to be used to detect the signal. This will result in our filter allowing more photon backgrounds which will reduce the accuracy of the measurements. The condition may become even worse in the daylight operations. After having conducted an extensive study in how a crystal changes its shape from thermal expansions caused by the pumped beam, or interactions with its surroundings, we have chosen the periodically poled lithium niobate crystal (PPLN), and experimentally confirmed its performance in the lab. Efficiency tests for the candidate source will soon be run outside the laboratory during the daytime to verify whether it meets the requirement. An entangled photon source with high stability and robustness can be achieved by improving the photon interferometer that is necessary to make the correlated photon pairs. Beam splitters are one of the optical devices commonly used to make such interferometers. The disadvantage of beam splitters that it is difficult to separate the pair with that much of large separation in the wavelengths (which is the wavelength difference between 791nm and 1550nm). Our team has come up with an alternative interferometer design which uses two beam displacers instead of the beam splitters, and its performances have been verified. Ground-to-ground EB QKD has already been well established, and now we are about to make a next huge step by applying it to a satellite networking system.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.007 | 0.002 |
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".