Liquid crystal spatial light modulator （LCSLM） realizing equal-intensity multiple beams often has some features, i.e., phase valley between two adjacent pixels, flybaek region when phase decreases immediately from 2...Liquid crystal spatial light modulator （LCSLM） realizing equal-intensity multiple beams often has some features, i.e., phase valley between two adjacent pixels, flybaek region when phase decreases immediately from 2~r to 0, and inevitable backplane curvature, which are different from those of most conventional diffractive optical elements （DOEs）, such as static DOEs. For optimal intensity uniformity, equal-intensity multi-beam generation must be considered for these artifacts. We present a tunable-grating method in which the intensity uniformity can be improved by considering the LCSLM artifacts. For instance, tuning phase modulation depth of the grating, called isosceles triangle multilevel phase grating （ITMPG）, can be used not only to improve the intensity uniformity, but also to fast steer four beams with narrow beamwidths, determined by the same effective aperture of ITMPG. Improved intensity uniformity and high relative diffraction efficiency are demonstrated through experiments with phase-only LCSLM.展开更多
Using the amorphous silicon (a-Si:H) film, which is cheap and has a small time lag, as the photoconductive layer of the liquid crystal light valve(LCLV) is an ideal selection. With the method of impedance matching use...Using the amorphous silicon (a-Si:H) film, which is cheap and has a small time lag, as the photoconductive layer of the liquid crystal light valve(LCLV) is an ideal selection. With the method of impedance matching used, we have designed and fabricated an a-Si:H LCLV and have obtained a clear image on a large screen projection system. The resolution of the valve was 20 lp/mm. The sensitometry measurement showed that the projection light level varies linearly with the writing light level when the latter is below 100 μW/cm2. The measurement of the transient response at the writing light level of 100 μW/cm2 indicated that the rise time and the decay time were 60 ms and 80 ms, respectively.展开更多
In this paper,the feasibility of a high laser damage threshold liquid crystal spatial light modulator based on gallium nitride(GaN)transparent conductive electrodes is proved.The laser-induced damage threshold(LIDT)is...In this paper,the feasibility of a high laser damage threshold liquid crystal spatial light modulator based on gallium nitride(GaN)transparent conductive electrodes is proved.The laser-induced damage threshold(LIDT)is measured,and a high LIDT reflective optically addressed liquid crystal light valve(OALCLV)based on GaN is designed and fabricated.The proper work mode of the OALCLV is determined;the OALCLV obtained a maximum reflectivity of about 55%and an on–off ratio of 55:1,and an image response is demonstrated.展开更多
The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crysta...The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crystal droplets, the model of orientation of droplets, and the contrast ratios of a cell are investigated. Droplet size, spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets. Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 60878048)the China Postdoctoral Science Foundation (Grant No. 20080440898)
文摘Liquid crystal spatial light modulator （LCSLM） realizing equal-intensity multiple beams often has some features, i.e., phase valley between two adjacent pixels, flybaek region when phase decreases immediately from 2~r to 0, and inevitable backplane curvature, which are different from those of most conventional diffractive optical elements （DOEs）, such as static DOEs. For optimal intensity uniformity, equal-intensity multi-beam generation must be considered for these artifacts. We present a tunable-grating method in which the intensity uniformity can be improved by considering the LCSLM artifacts. For instance, tuning phase modulation depth of the grating, called isosceles triangle multilevel phase grating （ITMPG）, can be used not only to improve the intensity uniformity, but also to fast steer four beams with narrow beamwidths, determined by the same effective aperture of ITMPG. Improved intensity uniformity and high relative diffraction efficiency are demonstrated through experiments with phase-only LCSLM.
基金Supported by the National Science Foundation of China
文摘Using the amorphous silicon (a-Si:H) film, which is cheap and has a small time lag, as the photoconductive layer of the liquid crystal light valve(LCLV) is an ideal selection. With the method of impedance matching used, we have designed and fabricated an a-Si:H LCLV and have obtained a clear image on a large screen projection system. The resolution of the valve was 20 lp/mm. The sensitometry measurement showed that the projection light level varies linearly with the writing light level when the latter is below 100 μW/cm2. The measurement of the transient response at the writing light level of 100 μW/cm2 indicated that the rise time and the decay time were 60 ms and 80 ms, respectively.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA25020303)。
文摘In this paper,the feasibility of a high laser damage threshold liquid crystal spatial light modulator based on gallium nitride(GaN)transparent conductive electrodes is proved.The laser-induced damage threshold(LIDT)is measured,and a high LIDT reflective optically addressed liquid crystal light valve(OALCLV)based on GaN is designed and fabricated.The proper work mode of the OALCLV is determined;the OALCLV obtained a maximum reflectivity of about 55%and an on–off ratio of 55:1,and an image response is demonstrated.
文摘The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crystal droplets, the model of orientation of droplets, and the contrast ratios of a cell are investigated. Droplet size, spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets. Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves.
