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31.
A. Waksberg 《International Journal of Infrared and Millimeter Waves》2002,23(9):1327-1335
Coupling losses have been calculated for laser resonators with unequal apertures and extended Fresnel Numbers. This was done using both, diffraction theory and a simple linear model.A close form expression was derived to calculate coupling losses with reasonable accuracies for a limited range of paramters. This should help in the preliminary design of hole coupling laser resonators. 相似文献
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Advanced high-pressure plasma diagnostics with hairpin resonator probe surrounded by film and sheath 下载免费PDF全文
The hairpin probe using microwave resonance in plasma is applicable to high pressure 1.33×10 3-1.01×10 5 Pa)) as developed recently.In this work,an analytic model of the hairpin resonator probe surrounded by a thin dielectric layer and a sheath layer is proposed.The correction factor due to these surroundings is analytically found and confirmed by electromagnetic field finite difference time domain simulation,thus enabling the accurate measurement of electron density in a high-pressure non-equilibrium uniform discharge. 相似文献
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基于严格电磁场理论,给出了微型谐振环形和Fishnet结构体内太赫兹波的严格表达式,并利用电磁场的边界条件分析了太赫兹波在微型谐振环形和Fishnet结构体内空间分布的增强效应。数值模拟结果表明:谐振环金属条附近的电场大于磁场,金属条附近的电场相对其他区域明显要强得多,开口处表现更为突出,太赫兹波在Fishnet结构体内电磁场的峰位处电场和磁场分布关于x对称;电场的极值出现在大十字架的上下四个角,而磁场的极值则出现在小十字架的上下两端点。同时用电磁场传输线理论对该现象作出一定的物理解释。收稿日期:; 修订日期: 相似文献
36.
Si基双环级联光学谐振腔应变检测研究 总被引:1,自引:0,他引:1
绝缘衬底上的硅材料制备的光学微环谐振腔结构具有高灵敏度、结构尺寸小和极低模式体积等特性,被广泛应用到光信息传递、惯性导航领域,但极少被应用到力学信号的测试,为此,研究了一种基于硅基光学微环谐振腔结构的悬臂梁式应力/应变敏感计,利用微环谐振腔环形波导径向形变量作为感应应力的中间物理量,在外界应力作用下,环形波导的半径将发生改变,使结构的光学谐振参数产生变化,从而使光学微环谐振腔谐振谱线发生明显红移,体现出良好的应力/应变敏感特性;通过设计双环级联光学微腔,并采用MEMS光刻、ICP腐蚀工艺制备了嵌入式光学微腔应变计结构,结合理论计算了悬臂梁结构的应力应变敏感特性,经仿真及实验得到,应变计结构的应力/应变灵敏度分别为0.185 pm·kPa-1,18.04 pm·microstrain-1,与单环微腔结构相比,线性量程增加了近50.3%,应力灵敏度提高了近10.6%,初步验证了嵌入式光学微腔结构进行高灵敏度应力/应变检测的可行性,有望实现新型光学力敏传感器件的微型化、集成化。 相似文献
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A Bessel-Gauss resonator (BGR) was proposed to produce the Bessel Gauss beams. In this paper transverse profiles and their corresponding losses of the BGR are computed by use of the entire matrix formalism and the transfer matrix method, and the computation results from two algorithms are compared. The computation results show that for the BGR there is no inconsistence in the mode fields yielded by two methods, and the transfer matrix methods are more accurate in the mode losses than the entire matrix formalism, which lead to a believable conclusion that the BGR with a convex-spherical mirror easily produces the fundamental Bessel-Gauss mode of good quality. 相似文献
39.
Duy-Thach PhanGwiy-Sang Chung 《Applied Surface Science》2011,257(9):4339-4343
Zinc oxide (ZnO) thin films were deposited on unheated silicon substrates via radio frequency (RF) magnetron sputtering, and the post-deposition annealing of the ZnO thin films was performed at 400 °C, 600 °C, 800 °C, and 1000 °C. The characteristics of the thin films were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The films were then used to fabricate surface acoustic wave (SAW) resonators. The effects of post-annealing on the SAW devices are discussed in this work. Resulting in the 600 °C is determined as optimal annealing temperature for SAW devices. At 400 °C, the microvoids exit between the grains yield large root mean square (RMS) surface roughness and higher insertion losses in SAW devices. The highest RMS surface roughness, crack and residual stress cause a reduction of surface velocity (about 40 m/s) and increase dramatically insertion loss at 1000 °C. The SAW devices response becomes very weak at this temperature, the electromechanical coupling coefficient (k2) of ZnO film decrease from 3.8% at 600 °C to 1.49% at 1000 °C. 相似文献
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Based on the paraxial vectorial theory of beams propagating in uniaxially anisotropic media, we have derived the analytical propagation equations of beams generated by Gaussian mirror resonator (GMR) in uniaxial crystals, and given the typical numerical example to illustrate our analytical results. Due to the anisotropy crystals, the ordinary and extraordinary beams originated by incident beams generated by GMR propagate with different diffraction lengths, thus the linear polarization state and axial symmetry of the incident beams generated by GMR do not remain during propagating in crystals. 相似文献