Investigation of circular Bragg reflection in an azo polymer with photoinduced chirality
Bibliographic record
Abstract
There has been recent interest in photoinduced chirality in azo polymers upon irradiation with circularly polarized light. The mechanism of ordering is thought to involve successive twisting of the achiral photoactive azo-containing side chains in response to the handedness of the pump polarization. In this study, a thin film of a liquid-crystalline azo polymer with a room-temperature nematic phase is irradiated with circularly polarized light and a circular Bragg reflection is observed in the absorption spectrum. When probed at normal incidence, the evolution of this selective reflection is monitored with increasing exposure. Then, the probing is carried out for various angles of incidence and the change in peak shape is studied. In the last experiment, the position of the Bragg reflection is monitored as the wavelength of the pump laser is varied. We propose that while the induced chirality is due to the circularly polarized light, the associated pitch may be large; the induced periodicity corresponding to the Bragg reflection may be the result of partial erasure due to a standing wave created by back reflection in thin films.
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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 | 0.000 |
| 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 | 0.001 |
| 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".