Photorefractive Bragg gratings in nematic liquid crystals aligned by a magnetic field

Journal Article · Tue Jun 01 00:00:00 EDT 1999 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.124127· OSTI ID:341352

Wiederrecht, G P ^[1]; Wasielewski, M R ^[1]

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1. Chemistry Division, Argonne National Laboratory, Argonne, Illinois 60439-4831 (United States)

Photorefractive Bragg gratings are observed in low-molar-mass nematic liquid crystals doped with electron donor and acceptor molecules. This is accomplished by alignment of the nematic liquid crystals in a 0.3 T magnetic field, which produces thicker homeotropic aligned samples than traditional surfactant techniques. Grating fringe spacings as low as 3.7 {mu}m are achieved with 176-{mu}m-thick samples, producing grating {ital Q} values of 33. Up to this point, low molar mass nematic liquid crystals have exhibited photorefractive gratings with Q{le}1. Asymmetric two-beam coupling and photoconductivity experiments are performed to verify the photorefractive origin of the gratings. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 341352
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 23 Vol. 74; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALIGNMENT
DIFFRACTION GRATINGS
DOPED MATERIALS
LIQUID CRYSTALS
MAGNETIC FIELDS
PHOTOCONDUCTIVITY
REFRACTIVE INDEX