Interaction of electromagnetic waves in planar waveguide with a nematic layer

Influence of dc Electric Field on the Hysteresis of Light-Induced Fréedericksz Transition in a Nematic Cell

“…Equation (4) involves the solutions of Maxwell's equations for the electric field of an incident light wave and the dc electric field in the nematic volume. In particular, in the geometric optics approximation, the electric field of a light beam has the form [32]…”

“…Therefore, deformations of the director field are assumed to be small. The director deviation angle and the incident light intensity 0 are expanded in series in the small parameter [32], namely, the maximum of the director deviation angle = ( = 0, = /2). This maximum is reached at the cell midpoint and the center of the light beam.…”

“…From whence, it follows that, if > 0, the LIFT occurs without the hysteresis. When the incident light intensity 0 achieves the orientational instability threshold th = Fr , the system smoothly transits from the homogeneous state with = 0 into an inhomogeneous one with ̸ = 0, and vice versa (see works [16,32]).…”

“…In particular, if the incident light intensity 0 increases from zero and achieves the value of th , the system, according to Eq. (13) [16,32], transits in a jump-like manner from the homogeneous state with = 0 into an inhomogeneous one with = = √︀ − . On the other hand, if the intensity 0 decreases from values higher than th , the system returns into the initial homogeneous state from the state with = √︀ − 2 at the light intensity ′ th = th − Fr 2 /(4 ) < th (see Eq.…”

“…The finite transverse size of a light beam was taken into account, while experimentally studying the LIFT hysteresis [18,[20][21][22][23]. The influence of the shape and the finite transverse light beam size on parameters of the LIFT hysteresis in an NLC cell with an infinitely rigid surface anchoring, but in the absence of external dc fields, was studied theoretically in works [32,33]. The influence of a finite energy of anchoring of NLCs with the cell surface on parameters of the LIFT hysteresis was studied theoretically in the fields of both an infinitely wide light beam [16,34] and a light beam with a finite width.…”