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1.
大模场宽频单模光子晶体光纤的设计与制备   总被引:1,自引:1,他引:0  
文章对无尽单模光子晶体光纤进行了理论设计,并提出了微结构光纤的制造工艺技术和相应的光纤拉丝工艺参数,制造出了较大模场的宽频单模光子晶体光纤,该光纤的芯直径为13.1 μm,微孔直径为3.2 μm,孔间距为8.2 μm,1 550 nm波长的模场直径为14.6 μm,1 550 nm的衰减为0.6 dB/km,1 383 nm水峰为14.9 dB/km.截止波长测试和近场光强分布检验表明,该光子晶体光纤确实具备较宽的单模工作范围.  相似文献   

2.
为了获得微结构光纤的平坦色散特性,设计了一种圆形排列的微结构光纤,其包层由周期分布的空气孔构成,通过有限元数值分析法对该微结构光纤基模的色散特性进行了数值仿真,研究了色散和纤芯圆孔尺寸以及波长的关系。结果表明:内外空气孔间距和直径对微结构光纤的色散曲线都有影响,但内包层大孔间距和第一圈小空气孔的直径对色散曲线的走向起决定作用。在内圈空气孔直径为3.1μm,其他空气孔直径为1.0μm,内圈空气孔中心间距为5μm,其他空气孔中心间距为4μm时,光纤在1.3μm波长的色散为19.5ps/(nm·km),在1.6μm波长的色散为26.5ps/(nm·km),在1.3~1.6μm波长范围内,其色散值变化范围为7ps/(nm·km)。  相似文献   

3.
用于激光能量传输的大纤芯微结构光纤的设计及制备   总被引:1,自引:1,他引:0  
设计和制备了一种传输高功率激光能量石英基质微结构光纤。光纤的外径为180μm,芯径为84μm,包层为双层空气孔。实验结果表明,对半导体激光的980nm和YAG激光的1 064nm波长的传输损耗分别为6dB/km和7dB/km,而最低损耗可达到1dB/km@935nm;在弯曲半径为0.25cm的条件下,弯曲的附加损耗为0.56dB/circle@980nm和0.416dB/circle@1 064nm;实验测得在980nm波长的实际模场面积为2 951.71μm2,与理论值2 951.4μm2相吻合。研制的光纤具有结构简单、柔软性好、易制备、低非线性、低损耗和高损坏阈值等特点,是高功率激光能量柔性传输系统的理想介质。  相似文献   

4.
孙虎  李稳  陆云清  陆懿  陈陶 《激光与红外》2015,45(6):697-701
设计了一种全固态六角晶格卤化银光子晶体光纤,光纤由 AgBr 基底和 AgCl 低折射率介质柱构成。运用全矢量有限元法研究了光子晶体光纤包层层数、占空比和晶格常数等结构参数对光纤有效折射率、损耗以及色散等传输特性的影响。经过参数优化,当包层层数为6,占空比为0.455,晶格常数为110μm 时,卤化银光子晶体光纤在10.6μm 处的泄露损耗仅为0.0195 dB /km,同时在4~14.5μm 中红外波段,色散值在0.3~0.7 ps/(nm·km)之间波动,展示出了极为优良的近零超平坦色散特性和低损耗特性。  相似文献   

5.
本文利用国产半导体激光器泵浦掺Yb3+光纤环形激光器获得成功.掺Yb3+光纤长3 m,与1053 nm/980 nm波分复用器(WDM)构成交叉耦合型全光纤环形腔.总腔长为4 m,泵浦波长980 nm,激光波长为1042.3 nm,斜率效率9.6%,激光阈值低于0.5 mW,利用可调谐钛宝石激光器泵浦,得到该光纤激光器的最佳泵浦波长为978 nm.  相似文献   

6.
载流子注入全内反射型GaAs/GaAIAs光波导开关   总被引:3,自引:0,他引:3  
研制出利用载流子注入能带填充效应制成的全内反射型(CI-TIR)GaAs/GaAIAs光波导开关。开关工作波长为0.87μm,工作电流70mA,消光比14dB,串话-13dB,该开关具有尺寸小,与偏振无关,无阻塞,易集成的优点。  相似文献   

7.
掺Yb3 双包层光子晶体光纤激光器的实验研究   总被引:5,自引:1,他引:4  
实验采用中心波长975nm的最大输功率5W的LD作泵源,掺Yb^3-双包层光子晶体作增益介质,二色镜和光纤端面构成F-P腔。光纤长6m;纤芯直径为3.9μm.对泵光的吸收系数为2300dB/m;内包层直径为200μm.大数值孔径设计(对泵光,数值孔径为0.7)。实验结果表明,在入纤泵浦功率1.73W时获得波长1.078μm、功率1.45W的单模激光,斜率效率为85.1%;模式竞争和自脉动效应是影响激光器输出稳定性能的主要因素。  相似文献   

8.
研制了一种高功率高边模抑制比及高波长稳定性的DBR 型掺铒光纤激光器。该激光 器使用980nm LD 作为泵浦源,并使用长度为2. 75m 的高掺杂浓度的掺饵光纤作为增益介质,在1. 55μm 波段获得了3dB 线宽为0. 2nm ,25dB 线宽为0. 4nm 的激光输出。最大输出光功率25mW ,输出功率稳定性±0. 01dB ,边模抑制比60dB ,波长稳定性0. 01dB (受光功率计精度的限制) ,阈值泵浦光功率8. 6mW ,斜率效率21. 7 %。  相似文献   

9.
基于改进的化学气相沉积(MCVD)工艺,结合溶液掺杂技术,成功制备出11μm/125μm掺镱保偏光纤,并研究了其激光性能。该光纤的纤芯数值孔径为0.09,双折射系数值为3.0×10-4,915 nm和976 nm处的包层吸收系数分别为2.48 dB/m和7.05 dB/m。搭建了全光纤振荡器结构测试平台,当掺镱保偏光纤长度为2.25 m、976 nm泵浦功率为57 W时,实现了最大输出功率为48.9 W、斜率效率为85.5%的激光输出,输出光谱呈洛伦兹型。  相似文献   

10.
研究了基于硫化物微结构光纤产生的超连续谱。设计了一种正常色散区色散平坦的硫化物芯/碲酸盐包层微结构光纤,该光纤能够获得超平坦的超连续谱。为了实现平坦的正常色散,对硫化物纤芯直径、空气孔大小和位置等光纤结构参数进行了优化,获得了波长范围在1.4~3μm之间、起伏小于4dB的超平坦超连续谱;同时还设计了一种硫化物芯/氟化物包层的微结构光纤,通过对光纤参数的优化,获得了波长从1.2~7μm的超宽超连续谱。  相似文献   

11.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

12.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

13.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

16.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

17.
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   

18.
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   

19.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

20.
Due to variable symbol length of digital pulse interval modulation(DPIM), it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation(FDPIM) method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.  相似文献   

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