共查询到19条相似文献,搜索用时 93 毫秒
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以一直径为Φ20mm、平行度为10″的晶体锗窗口零件为例,介绍了晶体窗口零件加工中的关键技术。由于该零件直径小,平行差精度要求特别高,且为单晶锗材料,因此要高质高效地加工出符合技术指标的零件有相当的难度。在研究中摒弃了人们常说的晶体零件无法进行光胶的思想,大胆尝试“光胶”的方法,并结合工艺研究中经常出现的问题,有针对性地提出一套加工高精度晶体零件的控制措施。通过该措施的实施,能够很好地加工出高质高效的晶体窗口零件。实践证明:该方法适于批量加工;合格率高;能够满足设计的高精度需求。 相似文献
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鉴于光学零件高陡度凹曲面的抛光是光学加工的一个难题,轮带光学确定性抛光方法是解决此类零件抛光的有效方法之一;提出轮带光学抛光技术的原理和方法。研究了轮带光学抛光方法修形的可行性,采用五轴精密数控机床系统对一块直径Ф80 mm的K9玻璃平面样镜进行了修形试验,经过3次迭代修形使其面形精度均方根误差(RMS)由初始的0109 λ提高到0028 λ,平均每次收敛率达到13。实验结果表明,应用轮带光学抛光技术进行光学镜面修形,面形收敛速度较快,加工精度较高。本实验验证了轮带光学抛光技术的修形能力,为高陡度光学零件的抛光提供了研究基础。 相似文献
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鉴于光学零件高陡度凹曲面的抛光是光学加工的一个难题,轮带光学确定性抛光方法是解决此类零件抛光的有效方法之一;提出轮带光学抛光技术的原理和方法。研究了轮带光学抛光方法修形的可行性,采用五轴精密数控机床系统对一块直径Ф80 mm的K9玻璃平面样镜进行了修形试验,经过3次迭代修形使其面形精度均方根误差(RMS)由初始的0.109 λ提高到0.028 λ,平均每次收敛率达到1.3。实验结果表明,应用轮带光学抛光技术进行光学镜面修形,面形收敛速度较快,加工精度较高。本实验验证了轮带光学抛光技术的修形能力,为高陡度光学零件的抛光提供了研究基础。 相似文献
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针对惯性约束聚变(ICF)系统中大口径超薄KDP晶体在不同夹持和不同姿态下的面形变化,采用有限元分析软件ANSYS,建立了大口径超薄KDP晶体在不同夹持和不同姿态下的应变模型及其边界条件的确定方法,计算了四周简支正面点力、四周固支正面压条、四周简支侧面点力、四周固支侧面压条4种夹持方式在30°和垂直姿态下大口径超薄KDP晶体的面形变化,并给出了面形变化的P-V值和RMS值。在此基础上,通过对不同夹持和不同姿态下KDP晶体面形变化的分析和比较,给出了四周固支正面压条是引起晶体面形变化相对较小的夹持方式的结论。 相似文献
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用激光蒸发方法产生了大量BxNy^-负离子,发现在其形过程中倾向于B-N成键,而团簇离子形成成的气相反应方式又使其组成偏离子理想晶体配比,产生了大量的B或N悬键。结合红外振动光谱实验,还对其他一些实验现象进行了讨论。 相似文献
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介绍CO_2激光测距机与热像仪的三种组合即机械组合、激光发射系统独立,激光接收与FLIR光学系统合一和FLIR与CO_2激光测距机光路全部合一方案原理,并对这三种组合进行比较,最后提出并讨论CO_2激光测距机与热像仪(FLIR)兼容技术中频带宽度匹配、激光光斑与探测器尺寸几何失配、红外光学零件加工和红外光学薄膜的设计与工艺等问题。 相似文献
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本文介绍了一种加工YVO4晶体薄片的新工艺。采用这一工艺,一次加工36片YVO4晶体薄片,成品率达到96%。在确保晶体加工质量的前提下,明显提高了加工效率。经过二年多的实际应用,这个新工艺很适用批量加工。 相似文献
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S. P. Palto M. I. Barnik I. V. Kasyanova A. R. Geivandov N. M. Shtykov V. V. Artemov M. V. Gorkunov 《JETP Letters》2016,103(1):25-29
The electro-optic effect in hybrid structures based on subwavelength metallic nanogratings in contact with a layer of a nematic liquid crystal has been experimentally studied. Metallic gratings are fabricated in the form of interdigitated electrodes, which makes it possible to use them not only as optical elements but also for the production of an electric field in a thin surface region of the layer of the liquid crystal. It has been shown that, owing to the electric-field-induced reorientation of molecules of the liquid crystal near the surface of the grating, it is possible to significantly control the spectral features of the transmission of light, which are caused by the excitation of surface plasmons. The electro-optic effect is superfast for liquid crystal devices because a change in the optical properties of the system requires the reorientation of molecules only in a very thin surface layer of the liquid crystal. 相似文献
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H. L. Margaryan V. K. Abrahamyan D. L. Hovhannisyan N. H. Hakobyan V. M. Aroutiounian V. V. Belyaev A. S. Solomatin 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2017,52(3):258-263
A technique is developed for recording the centrally-symmetric liquid crystal phase plates with the anisotropic orientation of molecules providing a smooth change of the optical axis in a thin film of liquid crystal polymer. The technique enables one to record the elements with the cylindrically-symmetric and planar-symmetric distributions. Such structures can be used to develop the optical elements with the new functional possibilities. Using the developed techniques, the polarization-sensitive Fresnel lens is realized which is functioning either as a collecting or as a scattering lens for the light beams with the orthogonal circular polarizations. 相似文献
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Yu. V. Gulyaev S. A. Nikitov D. A. Usanov A. V. Skripal V. N. Posadskii V. S. Tiazhlov A. V. Baykin 《Doklady Physics》2014,59(10):437-440
Structures containing periodically alternating elements, which are a source of high-order waves, are investigated as low-dimensional waveguide microwave photonic crystals. The band character of the transmittance and the reflectance of a photonic crystal, which consists of sequentially alternating dielectric layers and thin metallic plates partially overlapping the waveguide section, is revealed by the numerical modeling and the experimental investigation of amplitude-frequency characteristics. It has been shown that the application of metallic plates with gaps in the structure of the photonic crystal made it possible to decrease its longitudinal size substantially compared with photonic crystals fabricated based on elements made of alternating dielectric layers with various permittivities. 相似文献
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Probing thermal properties of vanadium dioxide thin films by time-domain thermoreflectance without metal film 下载免费PDF全文
《中国物理 B》2021,30(9):96801-096801
Vanadium dioxide(VO_2) is a strongly correlated material, and it has become known due to its sharp metal–insulator transition(MIT) near room temperature. Understanding the thermal properties and their change across MIT of VO_2 thin film is important for the applications of this material in various devices. Here, the changes in thermal conductivity of epitaxial and polycrystalline VO_2 thin film across MIT are probed by the time-domain thermoreflectance(TDTR) method.The measurements are performed in a direct way devoid of deposition of any metal thermoreflectance layer on the VO_2 film to attenuate the impact from extra thermal interfaces. It is demonstrated that the method is feasible for the VO_2 films with thickness values larger than 100 nm and beyond the phase transition region. The observed reasonable thermal conductivity change rates across MIT of VO_2 thin films with different crystal qualities are found to be correlated with the electrical conductivity change rate, which is different from the reported behavior of single crystal VO_2 nanowires. The recovery of the relationship between thermal conductivity and electrical conductivity in VO_2 film may be attributed to the increasing elastic electron scattering weight, caused by the defects in the film. This work demonstrates the possibility and limitation of investigating the thermal properties of VO_2 thin films by the TDTR method without depositing any metal thermoreflectance layer. 相似文献
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本文报导了用MOCVD技术制备的ZnS:Mn电致发光薄膜为立方晶相,结晶取向性好,颗粒大。从高倍率的扫描电镜拍摄的照片观察到薄膜的表面平滑。SIMS测量表明Mn2+在ZnS薄膜纵向分布均匀,但在两侧有起伏,可能的原因是在生长的初终阶段流量的突变使化合物的化学计量比偏离而产生位错,引起原子的局部堆积,并且由于初终阶段ZnS:Mn生长的衬底不同使原子堆积层厚度不同。 相似文献
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A. S. Yurkov 《Physics of the Solid State》2007,49(8):1536-1542
The effect of the improper ferroelastic transition on the IR spectra of the Hg2Cl2 crystal is considered. It is shown that, due to lattice anharmonicity, the distortions caused by the phase transition give rise to mixing of the normal modes of the higher symmetry phase of the crystal, which results in the appearance of extra poles in the frequency dependence of the lattice permittivity. Experimentally, such extra poles manifest themselves in the appearance of extra lines in the IR absorption spectra. Symmetry analysis shows that this effect in Hg2Cl2 is strongly anisotropic in the plane normal to the tetragonal axis of the crystal. 相似文献