Far-Field Patterns from Dye-Doped Planar-Aligned Nematic Liquid Crystals Under nanosecond Laser Irradiation
High-definition patterns were observed under 10-Hz-pulse-repetition-rate, nanosecond laser irradiation of azodye-doped planar-nematic liquid crystal layers at incident intensities I ~ 5-10 MW/cm^2 in a single beam configuration and without any feedback involved. An incident polarization parallel to the nematic director was used. Under periodic pulsed laser irradiation, far-field beam patterns at the output of a dye-doped liquid crystal layer changed kaleidoscopically from rings and stripes to multiple hexagons. This pattern-formation regime had a buildup time of several seconds to minutes. We explain the observed effect by diffraction of the laser beam on light-induced micrometer-size inhomogeneities inside the liquid crystal layer with absorption and refraction properties different from the surrounding area. Possible mechanisms of the formation of the inhomogeneities are discussed.
- Research Organization:
- Univ. of Rochester, NY (United States). Lab. for Laser Energetics
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FC52-92SF19460
- OSTI ID:
- 889584
- Report Number(s):
- DOE/SF/19460-690; 1653; 2005-185; TRN: US200721%%309
- Journal Information:
- Molecular Crystals and Liquid Crystals, Vol. 453; Conference: 11th International Topical Meeting on Optics of Liquid Crystals, Sand Key, FL, 2-7 October 2005
- Country of Publication:
- United States
- Language:
- English
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