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Seiichi Furumi*, Shiyoshi Yokoyama, Akira Otomo, Shinro Mashiko This Paper describes the study on laser action from UV-curable chiral nematic liquid crystals (CLCs) doped with a fluorescentdye before and after photopolymerization of CLC host when an optically active agent without crosslinkable moiety was dopedin a UV-curable nematic liquld crystal, the laser action from the CLC cell was quite different before and after photopolymerization. Before the polymerizntion, optically pumping of dye-doped CLC cells with a linearly polarized laser beam gave rise to the laseremission with circular polarization at the band edge of CLC reflection as a consequence of the internal distributed feedbackeffect. Successively, photopolymerization of the CLC with 365 nm light brought about the thorough disappearance of the CLCreflection band probably due to the phase separation leading to the emergence of amplified spontaneous emission of fluorescentdye by optically pumping. In contrast, the dye-doped CLC cell including a crosslinkable agent with a cholesteryl residue enabledthe mirrorless laser action after photopolymerization. This is becaus the selective reflection band of CLC host was retained by the planar atructure of cholesteric polymer network. |