Difluorooxymethylene-bridged(CF2O)liquid crystal(LC)with low viscosity is prepared and used as a fast response LC material.When the material is mixed with isothiocyanato LCs with high birefringence,the visco−elastic c...Difluorooxymethylene-bridged(CF2O)liquid crystal(LC)with low viscosity is prepared and used as a fast response LC material.When the material is mixed with isothiocyanato LCs with high birefringence,the visco−elastic coefficient of the mixture decreases evidently and,accordingly,the response performance increases.While the concentration of CF2O LCs is about 7%,the LC mixture approximately maintains high birefringence and exhibits a fastest response performance that is 14%higher than that of pure isothiocyanato LCs.Therefore,the LC material and mixing method could find useful applications in optical devices.展开更多
A wedge liquid crystal(LC)cell is designed and manufactured,and a dye-doping cholesteric LC laser formed by mutual diffusion of the cholesteric LC with different pitches.A laser that is tunable in the 558–624 nm rang...A wedge liquid crystal(LC)cell is designed and manufactured,and a dye-doping cholesteric LC laser formed by mutual diffusion of the cholesteric LC with different pitches.A laser that is tunable in the 558–624 nm range is obtained under moderate optical pumping,with a tuning range of 66 nm and a laser spectral tuning resolution of 1 nm,so as to achieve the spatial position of a wide range of tunable lasers.The laser threshold varies at different positions in the device,and the lasing thresholds of the dye-doping cholesteric LC cell at 40 and 9μm are 18 and 25μJ/pulse,respectively.The density of the photonic states is simulated in the experimental sample,and the result is in good agreement with the photonic band gap in our experiment,which not only explains the low-threshold laser at the band gap edge,but also predicts the experiment.展开更多
基金by the National Natural Science Foundation of China under Grant Nos 50703039 and 60736042.
文摘Difluorooxymethylene-bridged(CF2O)liquid crystal(LC)with low viscosity is prepared and used as a fast response LC material.When the material is mixed with isothiocyanato LCs with high birefringence,the visco−elastic coefficient of the mixture decreases evidently and,accordingly,the response performance increases.While the concentration of CF2O LCs is about 7%,the LC mixture approximately maintains high birefringence and exhibits a fastest response performance that is 14%higher than that of pure isothiocyanato LCs.Therefore,the LC material and mixing method could find useful applications in optical devices.
基金Supported by the National Natural Science Foundation of China under Grant No 60777011the Natural Science Foundation of Liaoning Province under Grant No L2010465Technology Project of Education Department of Liaoning Province under Grant No L2012070.
文摘A wedge liquid crystal(LC)cell is designed and manufactured,and a dye-doping cholesteric LC laser formed by mutual diffusion of the cholesteric LC with different pitches.A laser that is tunable in the 558–624 nm range is obtained under moderate optical pumping,with a tuning range of 66 nm and a laser spectral tuning resolution of 1 nm,so as to achieve the spatial position of a wide range of tunable lasers.The laser threshold varies at different positions in the device,and the lasing thresholds of the dye-doping cholesteric LC cell at 40 and 9μm are 18 and 25μJ/pulse,respectively.The density of the photonic states is simulated in the experimental sample,and the result is in good agreement with the photonic band gap in our experiment,which not only explains the low-threshold laser at the band gap edge,but also predicts the experiment.
