Optically band-tunable color cone lasing emission in a dye-doped cholesteric liquid crystal with a photoisomerizable chiral dopant
作者:C.-R. Lee、S.-H. Lin、H.-S. Ku、J.-H. Liu、P.-C. Yang、C.-Y. Huang、H.-C. Yeh、T.-D. Ji
DOI:10.1063/1.3364942
日期:2010.3.15
of an opticallyband-tunablecolorconelasingemission (CCLE) based on a dye-dopedcholestericliquidcrystal with a photoisomerizablechiraldopant. Experimental results indicate that the lasing band of the formed CCLE can be tuned optically among various color regions by adjusting the UV irradiated fluence. The optical band tunability of the laser is attributed to the presence of two chiral agents
New Chiral-Photochromic Dopant with Variable Helical Twisting Power and its use in Photosensitive Cholesteric Materials
作者:Alexey Yu. Bobrovsky、Natalia I. Boiko、Valery P. Shibaev
DOI:10.1080/10587250108025256
日期:2001.7
A new photosensitive chiral dopant based on cinnamic acid and isosorbide was synthesised. UV light action leads to E-Z photoisomerization of the dopant about C=C double bond of cinnamoyl fragment. Mixtures of the dopant with nematic and cholestric polymers were studied. It was shown, that planarly-oriented films of mixtures possess a selective light reflection in ultraviolet, visible and infrared regions of spectrum depending on the dopant concentration. The helical twisting power of the chiral dopant was calculated. UV light action on mixture films leads to a shift of selective light reflection peak to the long wavelength region of spectrum, which is explained by photoisomerization and decrease of the helical twisting power of the dopant. Kinetics of the process of photoinduced untwisting of the cholesteric helix was studied. Advantages of the use of the synthesised dopant and of mixtures based on it were demonstrated in comparison to earlier studied chiral-photochromic materials for optical data recording and storage.