Mirrorless Microcavity Spontaneously Formed in Ferroelectric Liquid Crystals

Abstract
We have observed second-harmonic generation (SHG) from ferroelectric liquid crystals (FLC) as a function of helicoidal pitch. Not only the transmitted but also the reflected SH intensities markedly increase when the wavelength of the SH light coincides with the optical pitch of the helicoid. This fact implies the existence of cavity action by FLC: the helicoidal structure confines the SH light generated inside.