共查询到20条相似文献,搜索用时 49 毫秒
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《红外与毫米波学报》2020,(3)
提出了一种基于光子晶体的二维多通道光学化学传感器。该器件由中心波长为3.3μm的四个腔组成,各通道工作波长间隔为10 nm。该传感器采用800 nm厚的绝缘体上硅材料,可利用标准CMOS技术加工。通过三维时差有限差分法对微腔结构的光学特性进行模拟。每个通道的传输效率为39%,通道之间的传输效率不一致性小于0.25dB。该传感器的功能为检测四氯化碳和苯溶液浓度,其灵敏度为209.2 nm/RIU。 相似文献
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雪粒径大小影响着积雪反照率的高低,从而影响着局地或全球能量收支平衡和气候变化,其影响程度取决于积雪本身的微物理特征和光学特性。在研究550nm、1030nm和1640nm波长处积雪光学特性的基础上,采用辐射传输方程模拟并分析了雪粒径对积雪双向反射率的影响。模拟结果表明近红外通道1030nm是反演雪粒径的敏感波长,积雪双向反射率在该波段随粒径和观测角度变化明显,多角度遥感信息可以更有效地体现积雪的微物理特征和光学特性,为利用多角度遥感数据反演雪粒径提供理论基础。 相似文献
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提出一种可实现351 nm波长激光高通量传输的终端光学组件(FOA)的物理设计方案,研究了设计优化方法,并利用神光Ⅱ装置第九路系统开展了实验研究。实验共进行了33发激光发射:激光光束净口径310 mm,时间脉冲宽度3 ns,1053 nm波长激光能量1000~4500 J。实验获得最高三次谐波转换效率69.6%和351 nm波长激光传输通量3.76 J/cm2,同时监测到高通量激光传输引起的动态环境污染物颗粒变化数和光学元件激光诱导损伤等现象。实验结果表明,通量密度约为3 J/cm2@351 nm的光学元件损伤主要是由激光传输散射鬼光束辐照材料所激发的污染物所致。 相似文献
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提出了一种基于体布拉格光栅(VBG)和横向啁啾体布拉格光栅(TCVBG)组合的双光栅外腔半导体激光器,该外腔半导体激光器采用反射率15%的体光栅和反射率17%的啁啾体布拉格光栅作为反馈元件和模式选择元件,实现特定波长的选择和调谐,实验研究了外腔激光器的功率-电流特性、光谱特性和波长调谐特性。实验结果表明:双光栅外腔半导体激光器最大输出功率为1.96 W,斜率效率为0.94 W/A,外腔效率达到78%。输出光谱为双波长,一个波长为808.6 nm,另一个波长连续可调,通过改变横向啁啾体光栅的位置,该波长可从800 nm调谐至815 nm,可调范围达15 nm,在整个可调范围内两个波长的谱线宽度(FWHM)均小于0.3 nm。 相似文献
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设计了一种高效的1060 nm大功率半导体激光器,该激光器包含有源层、波导层和光限制层。其中有源层采用InGaAs/GaAs量子阱(QW)结构,将该层控制在临界厚度范围内,提高腔内量子效率;波导层采用非故意掺杂GaAs材料非对称大光学腔结构,减小空腔损耗;光限制层采用掺杂的Al0.25Ga0.75As材料形成线性的过渡,以减小串联电阻。应用MOCVD对器件结构进行优化,外延,制作和封装测试,获得功率效率为47.4%的1060 nm半导体激光器。实验结果表明,腔内量子效率达到98.57%,腔损仅为0.273 cm-1。在室温下,QCW脉冲条件下制备的器件具有4 mm腔长和100μm条宽的器件,效率达到47.4%,峰值波长为1059.4 nm。 相似文献
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High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center. 相似文献
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In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy. 相似文献
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This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors. 相似文献
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YUXiao-hua XIANGYu-qun 《半导体技术》2005,30(2):30-32,37
An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB. 相似文献
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The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO>6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs. 相似文献
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Meihua Shen Wilfred Pau Nicolas Gani Jianping Wen Shashank Deshmukh Thorsten Lill Jian Zhang Hanming Wu Guqing Xing 《半导体技术》2004,29(8)
This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration. 相似文献
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White organic light-emitting devices based on fac tris(2- phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene 总被引:1,自引:0,他引:1
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V. 相似文献
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Complete approach to automatic identification and subpixel center location for ellipse feature 总被引:1,自引:0,他引:1
XUE Ting WU Bin SUN Mei YE Sheng-hua 《光电子快报》2008,4(1):51-54
To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction. 相似文献
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We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network. 相似文献