Ultrafast multi-directional devices for optical wireless communications
Bibliographic record
Abstract
Optical wireless communications (OWC) has become an increasingly attractive technology for dense urban environments, as it merges the high-speed capability of optical communications with the mobility of wireless operation. Early generations of OWC systems are now emerging as indoor (e.g., Li-Fi) networks and outdoor (e.g., free-space optical) links. Unlike contemporary point-to-point fibre-optic networks, however, these OWC systems typically demand bi-/multi- directional operations between distributed transceivers. With this in mind, various forms of multi-directional optical wireless transceivers are presented in this dissertation. A corner-cube (CC) optical wireless transceiver is introduced first, with orthogonal photoconductive (PC) switches facilitating OWC operation over a solid angle of π/2 steradians. The CC-PC transceiver is capable of simultaneous photodetection (via PC switches operating at a gigahertz bandwidth), optical retroflection (via a CC architecture operating over a solid angle of π/2 steradians), and optical modulation (via a liquid crystal modulator operating at a kilohertz bandwidth). The capabilities of the multi-directional optical wireless transceiver are then extended through the introduction of a spherical (SP) optical wireless transceiver. The SP-PC transceiver offers improved performance over that of the CC-PC transceiver. It is capable of simultaneous photodetection (via PC switches operating at a gigahertz bandwidth), optical retroflection (via refraction over a solid angle of 4π steradians), and optical modulation (via all-optical modulation at a terahertz bandwidth). The proposed optical wireless transceivers are well-suited to the demands of bi-directional OWC networks, with active downlink and passive uplink operation, and they yield great potential for future implementations of OWC networks.
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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 | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 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".