3C13 One- and two-photon pumped lasing from chiral nematic liquid crystal

Abstract

Here we report the lasing at the photonic band edge of chiral liquid crystals caused by visible and near-infrared laser light excitation. The samples used were chiral nematic liquid crystals doped with a laser dye (DCM). Visible (540 nm) and near-infrared (1000 nm) pump light was generated by a femtosecond laser system. In both case, the lasing occurred at the dielectric-band edge. Below threshold, the intensity of fluorescence by near-infrared pumping was proportional to the square of excitation pulse energy. Therefore, we concluded that the laser oscillation caused by near-infrared light pumping was the two-photon pumped lasing.