Efficient nonlinear optical ferroelectric liquid crystals for integrated optics devices

Liquid crystal displays, LC-materials and LPP photo-alignment

“…This design was shown to render thermally stable and highly efficient organic NLO-FLC-waveguides feasible. The resulting exceptionally large macroscopic NLO efficiency of X 2 = 5pm/V even exceeds X 2 (LiNbO 3 ) = 3pm/V of lithium niobate [43,44].…”

“…Schadt and collaborators used a completely different approach from the prior art demonstrating that thermally inherently stable and highly efficient NLO-active FLC devices are indeed feasible if the following four prerequisites are met [43,44]: (i) proper incorporation of NLO-active functional groups into FLC-molecules such that sufficiently broad FLC-phases combined with large spontaneous polarization P s result, (ii) generation of synergy between S C * -symmetry and NLO-activity on the molecular level via close proximity between NLO-moiety and large spontaneous polarization (P s ) group, (iii) transfer of molecular NLO-efficiency into a macroscopic FLC-wave-guiding device configuration by (iv) operation of the NLO/FLC-configuration in an electronically switchable mono-stable state (most important). The last condition was achieved by electronically switching a bi-stable NLO-FLC configuration into one of its two thermally inherently mono-stable states.…”

“…Fig. 10 shows the structure of a strongly NLO-active FLC molecule [43]. Because SBF-configurations enable electrical switching into one of its two stable states, it was shown that inherent long-term NLO stability is feasible within the operating temperature range of the SBF-material.…”

“…Because SBF-configurations enable electrical switching into one of its two stable states, it was shown that inherent long-term NLO stability is feasible within the operating temperature range of the SBF-material. In case of time limited bi-stability the NLO-active state can be fixed either by incorporating a glass-transition into the NLO-S C * -FLC-material and subsequent cooling slightly below T g [43], or by polymer stabilization. This design was shown to render thermally stable and highly efficient organic NLO-FLC-waveguides feasible.…”

Anisotropic Networks, Elastomers and Gels

“…Their temporal stability is much higher than that of analogous low molar mass ferroelectric S; compounds, even stabilized in a glassy state [9], as the dipolar order is fixed permanently in the anisotropic network. Ferroelectric monomers with a transverse chromophore axis with respect to the optic axis are used for this application due to the noncentrosymmetrical polar ordering and ease of alignment in a desired configuration.…”