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钛酸锶钡薄膜的室温光学性能研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了(Ba0.75Sr0.25)TiO3薄膜,研究了不同退火温度下样品的物相结构、薄膜的光致发光性能和光学透过率。结果表明:室温下非晶钛酸锶钡薄膜在蓝光激发下具有明显的发光现象,发光波长范围是500~650 nm,峰值在525 nm附近。延长非晶态薄膜的退火时间能够显著提高样品的发光强度,且发光强度随薄膜厚度增加而增大。晶态薄膜有微弱的发光现象。透射谱测试结果表明,钛酸锶钡薄膜在可见光范围内具有良好的光学透过率。 相似文献
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基于锑化铟材料在太赫兹波段的横向磁光效应,提出了一种金属-空气-锑化铟-金属非对称周期性亚波长线栅阵列结构的表面等离子体器件,研究了外加磁场和温度对不同频率透射波聚焦特性的影响.结果表明,在外加磁场强度B=0.6 T、温度T=172 K时,可实现0.8 THz透射光束的聚焦,焦点处能流密度透过率比没有外加磁场时增强28倍.对于不同频率入射波,通过主动调节磁场强度和温度,能实现从0.4—0.8 THz宽频带的聚焦,而且焦点处的透过率相比于无外加磁场时的普通狭缝聚焦透过率增强20倍以上,该器件是太赫兹波段理想的可调谐、宽频段、高透过率的聚焦器件. 相似文献
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针对二氧化钒纳米点阵从半导体到金属的可逆相变,考虑到点阵中各个点之间散射光的交互作用,基于VO2在不同温度和波长下的折射率和消光系数,以及小颗粒的吸收和散射特性,建立了VO2纳米颗粒的数学模型,研究了VO2纳米颗粒的相变光学特性.结果表明,随着波长变化,吸收截面相对散射截面占主导,金属相在980 nm附近出现吸收峰值|随着温度变化,可见光区域的消光系数变化较小,而红外区域较大,其中在近红外区域的消光系数变化最大.在纳米点阵中,消光截面随着颗粒间距变化,当颗粒间距增大时,消光峰值出现红移,且峰值大小也会随之增大|当间距超过一定数值后,峰值反而会逐渐减小.采用多孔氧化铝掩模的方法,通过磁控反应溅射制备VO2纳米点阵,测试结果表明其透过率比薄膜的透过率高. 相似文献
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In this paper, we observe the transmittance of fiber optic plates (FOPs) which were hot-pressed by different temperature and different pressure. Experimental results show that the effect of temperature and pressure in hot-pressing process on the transmittance is relatively large, especially temperature. Meanwhile, the FOPs hot-pressed by high-pressure and low-temperature are uniform and have high transmittance. 相似文献
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通过解析方法研究了高温等离子体的太赫兹波传输特性.研究发现,高温等离子体对太赫兹波高频频段透过率较高,表现为通带;对低频频段透过率较低,表现为阻带.这与冷等离子体中电磁波的传输特性是一致的.但其透射率还受到温度与磁场的影响,当改变高温等离子体的电子温度与磁场时,在阻带内会产生一尖锐的透射峰.这种现象在冷等离子体模型中从来没有出现过.本文主要对电子温度和外加磁场两个影响因素进行讨论.研究发现,禁带内出现的透射峰频率受磁场影响,而峰值幅度受温度影响.计算得到了不同外加磁场条件下产生高透过率(透射率约为1)时的电子温度.基于该结果进一步研究了透射峰出现的规律,并通过曲线拟合的方法得到了透射峰频率所遵循的计算公式.数值结果表明透射峰频率与外磁场之间为正比例函数关系,而峰值电子温度取值与外磁场的关系表现为指数规律.最后对拟合得到的方程采用时域有限差分法进行了验证,数值结果与解析解符合较好,证明了该研究的正确性. 相似文献
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A tunable filter is demonstrated based on a squared lattice two-dimensional photonic crystal. The filter is formed by a single semiconducting point defect and two neighboring waveguides. Modal properties of the defect modes and the transmittance of the proposed system are analyzed using supercell method and finite difference time domain method, respectively. We show that there is a narrow pass band for each temperature between 218 and 240 Kelvin. The peak of the pass band transmittance and the frequency can be highly tunable with the temperature of an intrinsic semiconducting point defect. Also, we have showed that the frequency and temperature of the desired high transmitted filter do not sensitive on the cavity size. 相似文献
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采用高温熔融法制备了Yb3+/Er3+掺杂的氟氧化物发光微晶玻璃,确定了最佳熔化温度(1 100℃)和退火温度(440℃,480℃)。测定得到基质玻璃的透过率为85%,掺入稀土后,透过率有所下降,并出现了稀土离子的特征吸收峰。980 nm半导体激光器(LD)激发下样品的上转换发射光谱存在4个明显的发射峰,分别为410,532,546和656 nm,对应于2H9/2→4I15/2,2H11/2→4I15/2,4S3/2→4I15/2和4F9/2→4I15/2跃迁。研究了不同Yb3+/Er3+(摩尔分数)和Er3+浓度对上转换发光强度的影响,当Yb3+∶Er3+=4∶1、Er3+摩尔分数为1.5%时,上转换发光强度达到最高。根据发光强度与泵浦功率之间的关系,确定了上转换发射均为双光子过程。讨论了Yb3+,Er3+离子间的能量传递,建立了上转换发光机制。 相似文献
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Photoluminescence in fluorescent 4H-SiC single crystal adjusted by B,Al,and N ternary dopants
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《中国物理 B》2019,(1)
This paper reports the sensitive effect of photoluminescence peak intensity and transmittance affected by B, Al, and N dopants in fluorescent 4H-SiC single crystals. The crystalline type, doping concentration, photoluminescence spectra,and transmission spectra were characterized at room temperature. It is found that the doped 4H-SiC single crystal emits a warm white light covering a wide range from 460 nm to 720 nm, and the transmittance increases from ~10% to ~60%with the fluctuation of B, Al, and N ternary dopants. With a parameter of C_(D-A), defined by B, Al, and N concentration, the photoluminescence and transmittance properties can be adjusted by optimal doping regulation. 相似文献
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采用溶胶-凝胶工艺在石英衬底上制备ZnO:Al(AZO)薄膜,通过不同温度的退火处理,研究了退火对AZO薄膜结构和光致发光特性的影响。XRD图谱表明:所制备的薄膜具有c轴高度择优取向,随着退火温度的升高,(002)峰的强度逐渐增强,同时(002)峰的半高宽逐渐减小,表明晶粒在不断增大。未退火样品的光致发光(PL)谱由361 nm附近的紫外带边发射峰和500 nm附近的深能级发射峰组成。样品经退火后,以500 nm为中心的绿带发射逐渐减弱,而带边发射强度有所增强,并且逐渐红移到366 nm附近,与吸收边移动的测试结果相吻合。对经过不同时间退火的样品分析表明,AZO薄膜的发光特性与退火时间也有很大关系,时间过短可见波段的发射较强,但时间过长会使晶粒发生团聚,导致紫外发射峰强度减弱。 相似文献
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中心波长121.6nm的真空紫外窄带滤光片设计和制备 总被引:3,自引:1,他引:2
采用双半波法布里-珀罗(F-P)干涉滤光片结构设计了中心波长在121.6 am的窄带滤光片,其峰值透射率为6.78%,通带半宽度为10.7 nm.通过设计、制备和测量峰值波长在217 nm的滤光片验证了设计用到的光学常数和膜厚定标都比较精确.在此基础上制备了121.6 nm的窄带滤光片,到合肥同步辐射实验室测量的结果是中心波长在120.74 nm,峰值透射率为5.94%,通带半宽度为12 nm.可以看出实际制备的滤光片和预先设计的基本吻合但还是有一定的偏差,最后对实际测量的和理论设计的偏差进行了分析. 相似文献
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Effect of substrate temperature on the structural and optical properties of ZnO and Al-doped ZnO thin films prepared by dc magnetron sputtering 总被引:1,自引:0,他引:1
Xue-Yong Li Hong-Jian Li Zhi-Jun Wang Zhi-Yong Xiong Bing-Chu Yang 《Optics Communications》2009,282(2):247-240
ZnO and Al-doped ZnO(ZAO) thin films have been prepared on glass substrates by direct current (dc) magnetron sputtering from 99.99% pure Zn metallic and ZnO:3 wt%Al2O3 ceramic targets, the effects of substrate temperature on the crystallization behavior and optical properties of the films have been studied. It shows that the surface morphologies of ZAO films exhibit difference from that of ZnO films, while their preferential crystalline growth orientation revealed by X-ray diffraction remains always the (0 0 2). The optical transmittance and photoluminescence (PL) spectra of both ZnO and ZAO films are obviously influenced by the substrate temperature. All films exhibit a transmittance higher than 86% in the visible region, while the optical transmittance of ZAO films is slightly smaller than that of ZnO films. More significantly, Al-doping leads to a larger optical band gap (Eg) of the films. It is found from the PL measurement that near-band-edge (NBE) emission and deep-level (DL) emission are observed in pure ZnO thin films. However, when Al was doped into thin films, the DL emission of the thin films is depressed. As the substrate temperature increases, the peak of NBE emission has a blueshift to region of higher photon energy, which shows a trend similar to the Eg in optical transmittance measurement. 相似文献
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利用传输矩阵法研究了镜像异质三周期一维光子晶体中的光子局域态随单轴应力发生变化的特性. 对于镜像异质三周期光子晶体, 由于其镜像结构, 破坏了光子晶体的有序性, 产生了一个缺陷态, 使其在较宽的光子禁带中心有一个光子局域态透射峰. 研究表明: 当对镜像异质三周期光子晶体施加单轴应力时, 其中的光子局域态透射峰会随着应力的改变而发生剧烈的变化. 当外部微弱的机械应力施加到光子晶体上时, 对光子晶体形成一个拉伸应变, 拉伸应变引起光子晶体结构的变化, 进而大幅度影响光子局域态透射峰的透射率.结果表明: 透射峰的透射率明显受单轴应力的影响. 这些特性可为用此结构的光子晶体设计超高灵敏度压力传感器提供理论参考.
关键词:
光子晶体
单轴应力
光子局域态
传输矩阵 相似文献
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Demonstration of Faraday anomalous dispersion optical filter with reflection configuration
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A narrow linewidth Faraday anomalous dispersion optical filter(FADOF)with reflection configuration is achieved for the first time based on the cesium(Cs)ground state 6S1/2 to the excited state 6P3/2 transition at 852 nm.Compared with the conventional FADOF with transmission configuration,reflection-type FADOF can greatly improve the transmittance of optical filter under the same experimental parameters,because it allows signal light to go and return through the atomic vapor cell.In our experiment,peak transmittance at Cs 6S1/2 F=4-6P3/2 transition is 81%for the reflection-type FADOF,and while 54%for the transmission-type FADOF when the temperature of Cs vapor cell and the axial magnetic field are 60℃and 19 G.The idea of this reflection-type FADOF design has the potential to be applied to the FADOF operating between two excited states to obtain higher transmittance. 相似文献
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