Measurement of the liquid crystal pretilt angle in cells with homogeneous and inhomogeneous liquid crystal director configuration

Abstract

Optical and electro-optical methods of liquid crystal (LC) director pretilt angle measurement are described for LC cells with homogeneous and inhomogeneous LC director distribution. The LC pretilt on both LC substrates can have the same or opposite direction. The phase retardation difference of both extraordinary and ordinary polarized rays passing through an LC cell with homogeneous and inhomogeneous LC director distribution has been calculated versus the LC pretilt angle θ(0) on the cell's substrates in the range 0≤θ(0)≤90°. The experimental procedure for phase retardation difference determination by measurement of the LC cell transmission between crossed polarizers for cells with LC tilted alignment is described. The method developed can also be used in optical compensator design.

P‐123: Oblique Light Incidence onto Hybrid Aligned Nematic (HAN) Cells for Optical Compensators

“…) dependences calculated have been used to determine the pretilt angle in every cell's type when the cell's phase retardation difference value ΔΦ has been measured in accordance procedure is described in detail in [18]. Besides of the LC pretilt angle value on the substrate with the OC film the polar anchoring energy W has been measured too by using a method described in [23].…”

“…The calculation method was firstly described in [16][17][18] for the LC cells with homogeneous, splay or bend director configuration. On the base of such calculation a method of the LC pretilt angle measurement has been developed in [18] for the cells with unknown arbitrary LC director configuration.…”

“…On the base of such calculation a method of the LC pretilt angle measurement has been developed in [18] for the cells with unknown arbitrary LC director configuration.…”

“…Besides, a method described in [18] did not allow measurement of the pretilt angles in the cells with asymmetric boundary conditions.…”

Microlense liquid crystal devices on the base of cylindrical objects

“…The B microlens is like a usual convex (collecting) lens and the S microlens is like a concave (scattering) lens. Different values of the LC pretilt angle can be obtained by using organosilicon substances or photoalignment technology . A method of deposition of a photoaligning coating into alumina oxide pores and filling them with LC material was described in Kozenkov et al Theoretical description of the LC alignment on the pores surface is presented in Dadivanyan et al…”