STP954: Nonlinear Rotatory Power of 90° Twisted Nematic Liquid Crystals

    Wu, S-T
    Hughes Research Laboratories, Malibu, California

    Hess, LD
    Hughes Research Laboratories, Malibu, California

    Pages: 8    Published: Jan 1986


    Abstract

    The optical rotatory power of 90° twisted nematic liquid crystal cells was measured with a CW CO2 laser and found to be intensity dependent for intensities > kW/cm2. We found that the rotatory power can either decrease monotonically or increase first and then decrease as the laser intensity increases; this effect depends on the liquid crystal layer thickness. A threshold-like transition was observed and the threshold power was found to be linearly proportional to the inverse square of the liquid crystal layer thickness. These results provide evidence that optical field induced molecular reorientation and thermal effect are responsible for the observed nonlinear optical effect. Self-defocusing, self-phase modulation and laser-induced damage were also observed with the use of a HeNe laser probe beam.

    Keywords:

    CO, 2, laser, diffractions, dynamic recovery, liquid crystals, nonlinear rotatory power, phase transition


    Paper ID: STP23102S

    Committee/Subcommittee: F01.02

    DOI: 10.1520/STP23102S


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