PA36 Observation of polar structures in liquid crystals by means of SHG microscope

Abstract

Symmetrical requirement for existence of polar structure is included in that for activity of the second-order nonlinear optics, because both of them are of even-order polarization phenomenon. Hence the second-order nonlinear optics becomes a powerful tool to investigate the polar properties. So far, the second harmonic generation (SHG) technique has been used mainly for confirming the existence of a polar order. Here, we suggest the new technique, SHG micro-imaging, to obtain much detailed information of microscopic polar structure in liquid crystals. In this report, we introduce the SHG microscope system and show several SHG micro-images of polar structures in various liquid crystalline systems.