Details
| Original language | English |
|---|---|
| Pages (from-to) | 2574-2584 |
| Number of pages | 11 |
| Journal | ACS Applied Electronic Materials |
| Volume | 1 |
| Issue number | 12 |
| Early online date | 7 Nov 2019 |
| Publication status | Published - 24 Dec 2019 |
| Externally published | Yes |
Abstract
The diffraction behavior of a polymer network liquid crystal (PNLC) was studied in in-plane switching (IPS) test cells and compared to the behavior seen in a neat liquid crystal. Due to the presence of polymer, the diffraction behavior was varied drastically: PNLCs are composites, which possess a specific domain size. The size of such polymer-induced domains was investigated with polarized optical microscopy and scanning electron microscopy. PNLCs are capable of continuous optical-phase modulation. It was found that electrical addressing with nonhomogenous electric fields can be useful to vary the phase modulation profile as compared to a neat LC. The diffraction patterns seen in a nematic LC were influenced by the applied addressing voltage and showed some limited tunability already. However, in the PNLC, the diffraction patterns were drastically varied as compared to a neat nematic LC. These gratings showed responses localized to the electrodes, had higher tuneability, and could also be useful to partially suppress the zeroth-diffraction order. Depending on the applied voltage, the diffraction efficiency could be tuned, efficiently. The presented results are instructive to understand the impact of a polymer network on the field-dependent reorientation of the liquid crystal director: if addressed with the same electric field profile, the responses were much more localized than in a neat nematic LC. In a straightforward numerical approach, domains in the PNLC samples were described by using cuboids. Diffraction patterns were then calculated based on the director reorientations seen and compared to the experimental data.
Keywords
- electro-optics, liquid crystal composite, numerical simulations, polymer network liquid crystal, tunable diffraction grating
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Materials Science(all)
- Materials Chemistry
- Chemistry(all)
- Electrochemistry
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In: ACS Applied Electronic Materials, Vol. 1, No. 12, 24.12.2019, p. 2574-2584.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Tunable Diffraction Gratings in Copolymer Network Liquid Crystals Driven with Interdigitated Electrodes
AU - Habibpourmoghadam, Atefeh
AU - Wolfram, Lukas
AU - Jahanbakhsh, Fatemeh
AU - Mohr, Benedikt
AU - Reshetnyak, Victor Y.
AU - Lorenz, Alexander
N1 - Funding Information: Funding by the German Research Council (DFG LO 1922/4-1, DFG GRK 1464) is gratefully acknowledged.
PY - 2019/12/24
Y1 - 2019/12/24
N2 - The diffraction behavior of a polymer network liquid crystal (PNLC) was studied in in-plane switching (IPS) test cells and compared to the behavior seen in a neat liquid crystal. Due to the presence of polymer, the diffraction behavior was varied drastically: PNLCs are composites, which possess a specific domain size. The size of such polymer-induced domains was investigated with polarized optical microscopy and scanning electron microscopy. PNLCs are capable of continuous optical-phase modulation. It was found that electrical addressing with nonhomogenous electric fields can be useful to vary the phase modulation profile as compared to a neat LC. The diffraction patterns seen in a nematic LC were influenced by the applied addressing voltage and showed some limited tunability already. However, in the PNLC, the diffraction patterns were drastically varied as compared to a neat nematic LC. These gratings showed responses localized to the electrodes, had higher tuneability, and could also be useful to partially suppress the zeroth-diffraction order. Depending on the applied voltage, the diffraction efficiency could be tuned, efficiently. The presented results are instructive to understand the impact of a polymer network on the field-dependent reorientation of the liquid crystal director: if addressed with the same electric field profile, the responses were much more localized than in a neat nematic LC. In a straightforward numerical approach, domains in the PNLC samples were described by using cuboids. Diffraction patterns were then calculated based on the director reorientations seen and compared to the experimental data.
AB - The diffraction behavior of a polymer network liquid crystal (PNLC) was studied in in-plane switching (IPS) test cells and compared to the behavior seen in a neat liquid crystal. Due to the presence of polymer, the diffraction behavior was varied drastically: PNLCs are composites, which possess a specific domain size. The size of such polymer-induced domains was investigated with polarized optical microscopy and scanning electron microscopy. PNLCs are capable of continuous optical-phase modulation. It was found that electrical addressing with nonhomogenous electric fields can be useful to vary the phase modulation profile as compared to a neat LC. The diffraction patterns seen in a nematic LC were influenced by the applied addressing voltage and showed some limited tunability already. However, in the PNLC, the diffraction patterns were drastically varied as compared to a neat nematic LC. These gratings showed responses localized to the electrodes, had higher tuneability, and could also be useful to partially suppress the zeroth-diffraction order. Depending on the applied voltage, the diffraction efficiency could be tuned, efficiently. The presented results are instructive to understand the impact of a polymer network on the field-dependent reorientation of the liquid crystal director: if addressed with the same electric field profile, the responses were much more localized than in a neat nematic LC. In a straightforward numerical approach, domains in the PNLC samples were described by using cuboids. Diffraction patterns were then calculated based on the director reorientations seen and compared to the experimental data.
KW - electro-optics
KW - liquid crystal composite
KW - numerical simulations
KW - polymer network liquid crystal
KW - tunable diffraction grating
UR - http://www.scopus.com/inward/record.url?scp=85086631808&partnerID=8YFLogxK
U2 - 10.1021/acsaelm.9b00579
DO - 10.1021/acsaelm.9b00579
M3 - Article
AN - SCOPUS:85086631808
VL - 1
SP - 2574
EP - 2584
JO - ACS Applied Electronic Materials
JF - ACS Applied Electronic Materials
IS - 12
ER -