Abstract
A spectroscopic Stokes polarimeter is used to directly measure the linearly, circularly, and randomly polarized components of light obtained on transmission of unpolarized light through thick chiral nematic liquid-crystal cells in the stop band. The Stokes parameters are simulated to fit the experimental data by use of the Berreman 4 × 4 transfer matrix by means of the Jones and Stokes vectors and taking into account multiple reflections at the interfaces of the cell. Excellent agreement is obtained. The transmitted light through a commercial cell is mainly circularly polarized at normal incidence, but a significant linearly polarized component is also observed. The model shows that this results from refractive-index mismatching at the liquid-crystal-alignment-layer interface, but a small linearly polarized component remains even with optimized index matching. An improved device configuration incorporating random defects at the exit boundary of the liquid crystal gives a highly circularly polarized output with virtually no linear or unpolarized components.
| Original language | English |
|---|---|
| Pages (from-to) | 760-766 |
| Number of pages | 7 |
| Journal | Journal of the Optical Society of America A: Optics and Image Science, and Vision |
| Volume | 22 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2005 Apr |
| Externally published | Yes |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Computer Vision and Pattern Recognition