Random and distributed feedback laser action using spontaneous liquid crystal-liquid crystal nano-scale phase separation

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The purpose of this study is to fabricate the nano-scale phase separated structure in the cholesteric liquid crystal -bent-core liquid crystal binary system, and to attain the combination of random laser mode and distributed feedback laser mode. Furthermore, gold nanoparticles are dispersed in this system, and we aimed the combination with surface plasmonic effect.At first, it was found that chiral molecules contained in the cholesteric phase was macroscopically phase separated by small-angle X-ray scattering. To overcome this problem, we tried to find the best condition to make the nano-scale phase separated structure by changing the cooling rate etc, but it was not successful to fabricate the such a structure exhibiting the good photonic band. For the coherent back scattering measurement system, At the same time, we modified the decan-thiol to gold nano-particle, and check whether particles are accumulated in the lower orientational order region of nematic phase. Unexpectedly, the particles are accumulated in the higher orientational order region. Under the study, on the other hand, we fabricated the CLC shells as a wate-in-oil-in-water (W/O/W) double emulsion using a microfluidic device. The oil phase of the W/O/W emulsion is made up of a CLC phase. The photonic structure in the CLC shellis confirmed by the spatial mapping of fluorescence emission spectra of a dye dissolved in the aqueous core region with a two-dimensional imaging spectrometer. The curious lasing characteristics in the CLC shell are also presented.