ABSTRACT
This chapter explores electro-optic measurement in frequency-domain to the nonlinear regime and apply to ferroelectric liquid crystals in the chiral smectic C (SmC) phase and antiferroelectric liquid crystals in the antiferroelectric smectic CA phase. Liquid crystal is an intermediate state of matter between a liquid and a solid. Most molecules that show liquid crystalline state have anisotropic shapes such as rods, disks, and ellipsoids. Especially, the anisotropy of refractive index and permittivity makes it possible to utilize liquid crystals for flat panel displays for TVs, personal computers, digital watches, calculators, and cellular phones. A sinusoidal electric field generated from a synthesizer equipped with a FFT analyzer is applied to a homogeneously aligned liquid crystal cell. The nonlinear electro-optical spectroscopy in the frequency-domain is applied to the Goldstone mode of a ferroelectric liquid crystal in the SmC phase and that of an antiferroelectric liquid crystal in the SmCA phase.
