The quadratic electro-optical effect in ferroelectric liquid crystal helical nanostructures: role of cell thickness and voltage frequency

It was reliably proved in recent years both theoretically and experimentally that the electrically controlled birefringence ΔnE of chiral smectic C* phase with subwavelength helix pitch is proportional to the square of the electric field E. The goal of the present work is to investigate the restrictions of the quadratic effect imposed by the thickness of the smectic C* layer between two solid substrates, and by the frequency of applied voltage. It is shown that these restrictions are mainly associated with the dielectric dispersion of the Goldstone mode under various boundary conditions.