Alignment properties of a ferroelectric nematic liquid crystal on the rubbed substrates

Abstract

The orientation characteristics of FNLC-919, a new material with a ferroelectric nematic phase at room temperature, were investigated. The alignment characteristic varied greatly depending on the relative rubbing direction on...

Lateral electric field switching in thin ferroelectric nematic liquid crystal cells

“…5(b) shows how the substrates are assembled with parallel rubbing and how the observed permanent polarization is oriented. The link between parallel rubbing and permanent polarization was also found by others, 12,26 in particular for thin cells. 27 In the nematic phase, parallel rubbing leads to a splay in the bulk due to the pretilt at the interfaces.…”

Electrically tunable chiral liquid crystal lens arrays

“…The fielddependent refractive index 𝑛(𝐸) can be written as 𝑛(𝐸)=𝑛𝑖+𝛿𝑛(𝐸), where 𝑛 / = ' ∥ 0%' ' 1 is the refractive index in the optically isotropic state at zero field applied; 𝑛 ∥ and 𝑛 3 are the refractive indices of the liquid crystal along and perpendicular to the director, respectively. Taking 𝑛 3 ≈ 1.53 and 𝑛 ∥ = 1.75 for FNLC 919 26 (another room temperature ferroelectric nematic liquid crystal from Merck), we get 𝑛 / ≈ 1.60. With this, from the measured 𝑓(𝐸) (see Figure 3a), we get 𝑛(𝐸)~1.61, i.e., d𝑛 = 0.01 at 2.7𝑉/µ𝑚.…”

Electrically Tunable Polymer Stabilized Chiral Ferroelectric Nematic Liquid Crystal Microlenses

“…The field-dependent refractive index n(E) can be written as n (E) = n i + 𝛿n(E), where n i = n ∥ +2n ⊥ 3 is the refractive index in the optically isotropic state at a zero field applied; n ∥ and n ⊥ are the refractive indices of the liquid crystal along and perpendicular to the director. Taking n ⊥ ≈ 1.53 and n ∥ = 1.75 for FNLC 919, [47] we get n i ≈ 1.60. We calculated the focal length values using the shape parameters and 𝛿n ≈ 0 for E < 1.0 V μm −1 , 𝛿n = 0.001 for E = 2.0 V μm −1 and 𝛿n = 0.004 for E = 2.5 V μm −1 (see Figure 1b).…”

“…The phase sequence in cooling was 80 ○ C N 1 44 ○ C N 32 ○ C N F 8 ○ C Cr. FNLC 919 was studied by Yu et al, [47] who reported that at room temperature it has a birefringence Δn ≈ 0.22 at 550 nm and showed a polarization peak without giving its value. Máthé et al found that the ferroelectric polarization of the pure FNLC 919 was 0.03 C m 2 at room temperature, [49] which was typical for ferroelectric nematic materials.…”