Bifurcation analysis of optically induced dynamics in nematic liquid crystals:: circular polarization at normal incidence

We present a detailed bifurcation analysis of the nonlinear reorientation dynamics of a homeotropically aligned nematic liquid-crystal film excited by a circularly polarized beam at normal incidence with the light intensity as the control parameter. The secondary bifurcation above the optical Freedericksz transition threshold is identified as a supercritical Hopf bifurcation leading to quasi-periodicity, and the subsequent discontinuous transition from quasi-periodicity to periodicity at higher intensity is identified as a homoclinic bifurcation. The bifurcation scenario is compared with the one obtained in the case of an ordinary light wave at small oblique incidence. Despite an analogous sequence of transitions, there are substantial differences. (c) 2005 Optical Society of America.