The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufact...The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5′10–4 K–1 and 5.4′10–10 Pa–1, respectively.展开更多
A mechanism of oxygen transportation in Czochralski growth of silicon crystals under a horizontal magnetic field (HMCZ) is proposed. Oxygen depleted surface melt, driven to the growth interface by the thermal Marangon...A mechanism of oxygen transportation in Czochralski growth of silicon crystals under a horizontal magnetic field (HMCZ) is proposed. Oxygen depleted surface melt, driven to the growth interface by the thermal Marangoni flow, determines oxygen concentration in the grown crystals. Systematic study was carried out to investigate effects of growth parameters on oxygen incorporation into crystals.展开更多
Based on the Cantor function and phase modulation, a tunable fractal axicon is formed on a liquid crystal on silicon （LCoS） with an improved generating method. It has higher focusing efficiency in higher fractal sta...Based on the Cantor function and phase modulation, a tunable fractal axicon is formed on a liquid crystal on silicon （LCoS） with an improved generating method. It has higher focusing efficiency in higher fractal stage and approaches to 100% theoretically. The on-axis intensity keeps its fractal structure unchanged in operation of fractal stages. The tunability of the axicon is demonstrated by tune fractal stage from 1 to 3 and focal length from 0.8 m to 1 m. We also provide details of theoretical analyses and experimental results.展开更多
市场背景 LCOS（Liquid Crystal on Silicon)为反射式液晶投影板，LCOS可视为LCD的一种，但传统的LCD是做在玻璃基板上．但LCOS则是长在矽晶圆上。LCD通常用穿透式投射的方式，光利用效率只有3％左右，解析度不易提高；LCOS则采用反射...市场背景 LCOS（Liquid Crystal on Silicon)为反射式液晶投影板，LCOS可视为LCD的一种，但传统的LCD是做在玻璃基板上．但LCOS则是长在矽晶圆上。LCD通常用穿透式投射的方式，光利用效率只有3％左右，解析度不易提高；LCOS则采用反射式投射光利用效率可达40％以上，因此被认为是数码投影技术中的明星级产品。展开更多
This paper describes the fundamentals of phase-only liquid crystal on silicon(LCOS)technology,which have not been previously discussed in detail.This technology is widely utilized in high efficiency applications for r...This paper describes the fundamentals of phase-only liquid crystal on silicon(LCOS)technology,which have not been previously discussed in detail.This technology is widely utilized in high efficiency applications for real-time holography and diffractive optics.The paper begins with a brief introduction on the developmental trajectory of phase-only LCOS technology,followed by the correct selection of liquid crystal(LC)materials and corresponding electro-optic effects in such devices.Attention is focused on the essential requirements of the physical aspects of the LC layer as well as the indispensable parameters for the response time of the device.Furthermore,the basic functionalities embedded in the complementary metal oxide semiconductor(CMOS)silicon backplane for phase-only LCOS devices are illustrated,including two typical addressing schemes.Finally,the application of phase-only LCOS devices in real-time holography will be introduced in association with the use of cutting-edge computer-generated holograms.展开更多
为了满足动态星模拟器大视场、高精度的技术要求,针对传统星模拟器光学系统的技术特点,提出了一种基于硅基液晶(liquid crystal on silicon,LCOS)光学拼接技术的动态星模拟器光学系统设计方案。结合动态星模拟器的技术指标,使用LCOS作...为了满足动态星模拟器大视场、高精度的技术要求,针对传统星模拟器光学系统的技术特点,提出了一种基于硅基液晶(liquid crystal on silicon,LCOS)光学拼接技术的动态星模拟器光学系统设计方案。结合动态星模拟器的技术指标,使用LCOS作为星图显示的核心器件,通过LCOS光学拼接技术来实现星图显示覆盖全视场并满足拼接误差≤10″的拼接结果。根据动态星模拟器的工作原理,设计小畸变、平场复消色差的准直光学系统以实现动态星模拟器实时准确模拟星点,其设计结果表明:在10.2°视场角内准直光学系统相对畸变≤0.025%,调制传递函数(modulation transfer function,MTF)在60 lp/mm达到0.7。通过经纬仪实际测量,其星对角距误差≤25″,单像元等效张角误差≤6″,满足设计指标中的要求。展开更多
在计算机视觉研究领域,采集到的图像通常由于被测物体局部高亮或局部镜面反射导致局部过饱和,从而影响测量系统的后续数据处理。针对此问题,根据反射式硅基液晶能够逐像素调节入射光的发射率的性质,采用高解析度硅基液晶(liquidcrystal ...在计算机视觉研究领域,采集到的图像通常由于被测物体局部高亮或局部镜面反射导致局部过饱和,从而影响测量系统的后续数据处理。针对此问题,根据反射式硅基液晶能够逐像素调节入射光的发射率的性质,采用高解析度硅基液晶(liquidcrystal on silicon,LCoS)和图像传感器(CCD或CMOS)相结合,设计了基于LCoS的图像亮度调节硬件系统。根据硅基液晶与图像传感器的光学性质,确立了摄像机模型像平面和LCoS掩膜平面之间的映射关系,提出了基于空间映射的像素对应算法,实验证明,该算法准确、可靠,可以实现图像亮度的像素级调整。展开更多
提出采用反射型LCOS(Reflective Liquid Crystal on Silicon-RLCOS)器件实现动态红外场景仿真,阐述了RLCOS器件的结构及信号写入原理。利用液晶指向矢分布计算模型和光在液晶中传播规律计算模型,分析了液晶光阀的电光特性,结果表明,如...提出采用反射型LCOS(Reflective Liquid Crystal on Silicon-RLCOS)器件实现动态红外场景仿真,阐述了RLCOS器件的结构及信号写入原理。利用液晶指向矢分布计算模型和光在液晶中传播规律计算模型,分析了液晶光阀的电光特性,结果表明,如果选取一组适当的光阀参数,可使光阀在中波和长波红外波段均有较好的调制特性,输出红外辐射功率与像素电压有较近似的线性关系,可以达到较好的仿真效果。展开更多
硅基液晶(liquid crystal on silicon,LCoS)微显示芯片是一种结合了CMOS芯片和液晶显示的硅基微显示技术,具有体积小、分辨率高和帧率高等特点,可以广泛应用于便携激光投影、AR眼镜、车载HUD和智能制造等领域。介绍了LCoS微显示芯片的...硅基液晶(liquid crystal on silicon,LCoS)微显示芯片是一种结合了CMOS芯片和液晶显示的硅基微显示技术,具有体积小、分辨率高和帧率高等特点,可以广泛应用于便携激光投影、AR眼镜、车载HUD和智能制造等领域。介绍了LCoS微显示芯片的结构、关键技术和驱动方式,并提出了一种高分辨率、高帧率的LCoS显示芯片设计方法,采用模拟像素驱动、高速数据接口和时序彩色显示方案,分辨率达到了1080 P,刷新帧率达到了360 HZ。展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51105347)National Key Technology R&D Program of Ministry of Science and Technology of China(Grant No.2011BAI02B03)
文摘The accurate measurement on the compressibility and thermal expansion coefficients of density standard liquid at 2329kg/m3（DSL-2329） plays an important role in the quality control for silicon single crystal manufacturing. A new method is developed based on hydrostatic suspension principle in order to determine the two coefficients with high measurement accuracy. Two silicon single crystal samples with known density are immersed into a sealed vessel full of DSL-2329. The density of liquid is adjusted with varying liquid temperature and static pressure, so that the hydrostatic suspension of two silicon single crystal samples is achieved. The compression and thermal expansion coefficients are then calculated by using the data of temperature and static pressure at the suspension state. One silicon single crystal sample can be suspended at different state, as long as the liquid temperature and static pressure function linearly according to a certain mathematical relationship. A hydrostatic suspension experimental system is devised with the maximal temperature control error ±50 μK; Silicon single crystal samples can be suspended by adapting the pressure following the PID method. By using the method based on hydrostatic suspension principle, the two key coefficients can be measured at the same time, and measurement precision can be improved due to avoiding the influence of liquid surface tension. This method was further validated experimentally, where the mixture of 1, 2, 3-tribromopropane and 1,2-dibromoethane is used as DSL-2329. The compressibility and thermal expansion coefficients were measured, as 8.5′10–4 K–1 and 5.4′10–10 Pa–1, respectively.
文摘A mechanism of oxygen transportation in Czochralski growth of silicon crystals under a horizontal magnetic field (HMCZ) is proposed. Oxygen depleted surface melt, driven to the growth interface by the thermal Marangoni flow, determines oxygen concentration in the grown crystals. Systematic study was carried out to investigate effects of growth parameters on oxygen incorporation into crystals.
文摘Based on the Cantor function and phase modulation, a tunable fractal axicon is formed on a liquid crystal on silicon （LCoS） with an improved generating method. It has higher focusing efficiency in higher fractal stage and approaches to 100% theoretically. The on-axis intensity keeps its fractal structure unchanged in operation of fractal stages. The tunability of the axicon is demonstrated by tune fractal stage from 1 to 3 and focal length from 0.8 m to 1 m. We also provide details of theoretical analyses and experimental results.
文摘市场背景 LCOS（Liquid Crystal on Silicon)为反射式液晶投影板，LCOS可视为LCD的一种，但传统的LCD是做在玻璃基板上．但LCOS则是长在矽晶圆上。LCD通常用穿透式投射的方式，光利用效率只有3％左右，解析度不易提高；LCOS则采用反射式投射光利用效率可达40％以上，因此被认为是数码投影技术中的明星级产品。
基金This work was supported by the National Natural Science Foundation of China(61307077)Beijing Natural Science Foundation(4144076)+1 种基金China Postdoctoral Science Foundation(2013M530613)This work was also supported by an EPSRC Platform Grant for LC Photonics(EP/F00897X/1).
文摘This paper describes the fundamentals of phase-only liquid crystal on silicon(LCOS)technology,which have not been previously discussed in detail.This technology is widely utilized in high efficiency applications for real-time holography and diffractive optics.The paper begins with a brief introduction on the developmental trajectory of phase-only LCOS technology,followed by the correct selection of liquid crystal(LC)materials and corresponding electro-optic effects in such devices.Attention is focused on the essential requirements of the physical aspects of the LC layer as well as the indispensable parameters for the response time of the device.Furthermore,the basic functionalities embedded in the complementary metal oxide semiconductor(CMOS)silicon backplane for phase-only LCOS devices are illustrated,including two typical addressing schemes.Finally,the application of phase-only LCOS devices in real-time holography will be introduced in association with the use of cutting-edge computer-generated holograms.
文摘为了满足动态星模拟器大视场、高精度的技术要求,针对传统星模拟器光学系统的技术特点,提出了一种基于硅基液晶(liquid crystal on silicon,LCOS)光学拼接技术的动态星模拟器光学系统设计方案。结合动态星模拟器的技术指标,使用LCOS作为星图显示的核心器件,通过LCOS光学拼接技术来实现星图显示覆盖全视场并满足拼接误差≤10″的拼接结果。根据动态星模拟器的工作原理,设计小畸变、平场复消色差的准直光学系统以实现动态星模拟器实时准确模拟星点,其设计结果表明:在10.2°视场角内准直光学系统相对畸变≤0.025%,调制传递函数(modulation transfer function,MTF)在60 lp/mm达到0.7。通过经纬仪实际测量,其星对角距误差≤25″,单像元等效张角误差≤6″,满足设计指标中的要求。
文摘在计算机视觉研究领域,采集到的图像通常由于被测物体局部高亮或局部镜面反射导致局部过饱和,从而影响测量系统的后续数据处理。针对此问题,根据反射式硅基液晶能够逐像素调节入射光的发射率的性质,采用高解析度硅基液晶(liquidcrystal on silicon,LCoS)和图像传感器(CCD或CMOS)相结合,设计了基于LCoS的图像亮度调节硬件系统。根据硅基液晶与图像传感器的光学性质,确立了摄像机模型像平面和LCoS掩膜平面之间的映射关系,提出了基于空间映射的像素对应算法,实验证明,该算法准确、可靠,可以实现图像亮度的像素级调整。
文摘提出采用反射型LCOS(Reflective Liquid Crystal on Silicon-RLCOS)器件实现动态红外场景仿真,阐述了RLCOS器件的结构及信号写入原理。利用液晶指向矢分布计算模型和光在液晶中传播规律计算模型,分析了液晶光阀的电光特性,结果表明,如果选取一组适当的光阀参数,可使光阀在中波和长波红外波段均有较好的调制特性,输出红外辐射功率与像素电压有较近似的线性关系,可以达到较好的仿真效果。
