数字电影滤光反射镜光谱设计

为了满足数字电影光学系统色温要求及提高光源能量利用效率,降低设计及光学薄膜镀制难度,计算了色温变化小、光源利用效率高的可见光高反射光谱波段。根据椭球滤光反射镜的工作原理及滤光薄膜的光谱特性,结合氙灯光源光谱及人眼的视觉函数,分析了可见光不同光谱波段对系统光效率及色度坐标的影响。获得了可见光波段光效利用率高,色度参数变化小的波段范围,解决了数字电影反光镜滤光薄膜可见光高反射波段初始设计问题。由滤光薄膜设计及镀制结果得到,405～690nm波长范围可作为数字电影滤光反射镜薄膜高反射区域,相比与氙灯光源光谱,x、y色度偏差不超过0.001,理论反射光光效率达99%以上。

多层介质膜光谱调制反射镜的反应离子束刻蚀误差容限

在千焦拍瓦高功率放大系统设计中,激光脉冲的时空和光谱整形技术一直受到人们的广泛关注。利用反应离子束刻蚀等微纳超精细加工而成的多层电介质结构反射镜可在高功率条件下实现啁啾脉冲的光谱整形。在光谱整形介质结构反射镜的设计与制造中,需要根据要求的反射率来合理提出反应离子束刻蚀误差容限指标。推导出反应离子束刻蚀误差容限的解析表达式。针对神光Ⅱ千焦拍瓦高功率放大系统设计中提出的多层介质光谱调制反射镜,分析了调制结构反射镜各层加工的容许误差,确定了反应离子束刻蚀误差容限指标。研究表明:刻蚀高折射率介质的加工误差容限为35 nm;刻蚀低折射率介质的加工误差容限为62 nm。此外,还从使用需要和加工难易的角度,对刻蚀方案进行了讨论。就加工难易程度而言,优选反应离子束刻蚀方案,且采用刻蚀并残留低折射率介质的方案更容易实现。

Improvement of visible light-induced photocatalytic performance by Cr-doped SrTiO_3-carbon nitride intercalation compound (CNIC) composite

Novel organic-inorganic composite photocatalyst offers new opportunities in the practical applications of photocatalysis. Novel visible light-induced Cr-doped Sr Ti O3–carbon nitride intercalation compound(CNIC) composite photocatalysts were synthesized. The composite photocatalyst was characterized by X-ray diffraction(XRD), field-emission scanning electron microscopy(FESEM), high-resolution transmission electron microscopy(HRTEM), Fourier transform infrared(FT-IR) spectroscopy, UV-vis diffuse reflection spectroscopy, photoluminescence(PL) spectroscopy, and BET surface area analyzer. The photocatalytic oxidation ability of the novel composite photocatalyst was evaluated using methyl orange(MO) as a target pollutant. The photocatalysts exhibited a significantly enhanced photocatalytic performance in degrading MO. For maximizing the photodegradation activity of the composite photocatalysts, the optimal CNIC content was determined. The improved photocatalytic activity of the as-prepared Cr-doped Sr Ti O3–CNIC composite photocatalyst may be attributed to the enhancement of photo-generated electron–hole separations at the interface.

Design of fiber-optic collector for spectrometer based on curved mirror

To enlarge the detection range of traditional fiber-optic spectrometer,two rotating parabolic mirrors were first used in the design of fiber-optic collector for spectrometer,which can extend the detection range of spectrometer from centimeter-scale to50m,as a super-low altitude remote sensing detector under passive lighting conditions.According to the performance requirements of fiber-spectrometer for optical collector,this study deduced the calculation formulae of design size of parabolic optical collector applied to different sensitivity spectrometers,different detection targets,different detection ranges and different weathers.Based on the calculation results,the model of fiber-optic collector with a diameter of16mm and a height of7.8mm was designed by ZEMAX.And then,TracePro,a light simulation software,was applied to ray tracing.The simulation results of optical radiation magnification agrees well with theoretical value,and the relative error is less than0.78%.This optical collector can effectively extend the detection range of spectrometer and expand its application fields and scopes.Compared with traditional refractive optical collector,it has several advantages of compact structure,low weight and low cost.

Sharp scattering spectra induced brilliant and directional structural colors

Structural color materials,which generate colors through the interaction between light and nano-microstructures,have always been research hotspots in the fields of display,anticounterfeiting and stimuli-responsive materials.Structural colors based on scattering have received increasing attention due to their wider viewing angles than that originating from the specular reflection of photonic crystals.However,the wide scattering spectrum of an amorphous structure leads to lower purity and brightness of the appeared colors.Few researchers have focused on the scattering of ordered structures due to their strong reflection and diffraction in the visible regions.In this work,by building ordered films(OFs)using SiO2 spheres(refractive index n=1.46)with a diameter of 300–500 nm,for the first time,sharp scattering spectra with narrow full width at half-maximum(FWHM,24 nm)were generated.Importantly,under ambient light,brilliant colors covering the entire visible region can be observed,and a formula was proposed to calculate the scattering spectra of OFs.Moreover,rainbow structural color was realized under irradiation of the nonparallel light,and full-spectrum structural color patterns were fabricated using building blocks with a single particle size by a spraying method.Finally,a composite structure was constructed to explore possibilities in the field of flexible transparent displays.

Hydrothermal synthesis and characterization of rare-earth ruthenate pyrochlore compounds R_2Ru_2O_7(R=Pr_(3+),Sm(3+)-Ho(3+))

A series of pyrochlore oxides, R2Ru2O7 (R=Pr3+, Sm3+–Ho3+) were synthesized under mild hydrothermal conditions. All the samples crystallize in uniform octahedron characteristically. The products were characterized by powder X-ray diffraction, scanning electron microscopy, energy-disperse X-ray spectroscopy, and dc susceptibility, and the factors that affected the crystallization were discussed. It was found that the purity of products depends strongly on the raw materials and the amount of alkalinity in the initial reaction mixtures. The ZFC and FC susceptibilities of all of the compounds R2Ru2O7 at low temperature were also measured and discussed.