Light-induced chaotic rotations in nematic liquid crystals

Area of Science:

• Optics and Photonics
• Soft Matter Physics
• Nonlinear Dynamics

Background:

• Nematic liquid crystals exhibit complex behaviors when subjected to optical excitation.
• Understanding nonlinear phenomena in liquid crystals is crucial for developing advanced optical devices.
• Boundary conditions invariant by rotation were applied to the liquid-crystal film.

Purpose of the Study:

• To investigate the nonlinear rotation regimes in optically excited nematic liquid crystals.
• To identify the transition to chaos and its underlying mechanisms.
• To develop a model explaining the observed dynamics.

Main Methods:

• Optical excitation with circularly polarized light.
• Circularly symmetric intensity profile with a small beam diameter.
• Observation of nonlinear rotation regimes and transition to chaos via quasiperiodicity.
• Development of a coupled rotator model for qualitative explanation.

Main Results:

• Various nonlinear rotation regimes were observed.
• A transition to chaos via quasiperiodicity was identified by increasing light intensity.
• Transverse nonlocal effects were suggested as the cause of the observed dynamics.

Conclusions:

• The study reveals complex nonlinear dynamics in liquid crystals under specific optical conditions.
• Transverse nonlocal effects play a significant role in the observed chaotic transitions.
• A simple coupled rotator model provides a qualitative understanding of the liquid-crystal dynamics.