Deep optical penetration dynamics in photobending.

Abstract

We model both the photostationary state and dynamics of an illuminated, photosensitive, glassy liquid crystalline sheet. To illustrate the interplay between local tilt θ of the sheet, effective incident intensity, curvature, and dynamics, we adopt the simplest variation of local incident light intensity with angle, that is, cosθ. The tilt in the stationary state never overshoots the vertical, but maximum curvature could be seen in the middle of the sheet for intense light. In dynamics, overshoot and self-eclipsing arise, revealing how important moving fronts of light penetration are. Eclipsing is qualitatively as in the experiments of Yu et al. [Y. Yu, M. Nakano, and T. Ikeda, Nature (London) 425, 145 (2003)].