Optical second-harmonic generation enhanced by a twist defect in ferroelectric liquid crystals

Abstract
Second-harmonic generation (SHG) spectra were numerically calculated in ferroelectric liquid crystals with a twist defect. It is shown that SHG is enhanced when the SHG wavelength is close to the defect mode. The spectral width of the enhanced peak becomes sharper with increasing the sample thickness at the same rate for the width of the defect mode peak. The SHG peak intensity increases with about seventh power of the sample thickness.