共查询到19条相似文献,搜索用时 515 毫秒
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根据多光束干涉原理,理论上分析了棱镜-漏波导耦合器,且与棱镜-波导耦合器作了比较,给出正确使用这两种耦合器的判据.分析结果表明,在强耦合条件下,棱镜-漏波导耦合器可用于薄膜参数测量和光波导输入-输出耦合;对于弱耦合,本文的结果与Tien和Ulrich的理论一致. 相似文献
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本文指出了在棱镜耦合状态下降低平板波导基模截止厚度的途径,用文中提出的准对称波导法测量了薄的MgO膜的折射率和厚度,并给出了测量结果. 相似文献
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本文对棱镜耦合法测波导衬底折射率进行了实验研究,在两种入射情况下,对石英玻璃、CaF_2、LiF衬底及C-813-8胶块进行了折射率测量,并得到有益的实验结果. 相似文献
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依据全反射理论和棱镜耦合原理,实现了对棱镜折射率及波导薄膜材料折射率和厚度的同步测量。使用高准直半导体激光器激光入射到棱镜内部与波导膜的分界面上,逐步旋转棱镜或改变棱镜的入射角,得到棱镜耦合M线,曲线前面几组的波谷为波导模激发,在M线左侧收尾处有一个不完整波峰,其反射光强随入射角迅速衰减,为全反射时的临界点,由此可实现棱镜及波导薄膜参数的同步测量;用此法测量了棱镜耦合一体化平面波导棱镜的折射率和聚甲基丙烯酸甲酯(PMMA)聚合物波导薄膜的折射率和厚度。测量棱镜折射率精度为±1.9×10-4,波导薄膜折射率和厚度的精度分别为±6.2×10-4 μm和±1.6×10-2 μm。 相似文献
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利用溶胶-凝胶分子模板法在表面覆金的玻璃基底上制备275 nm厚的介孔二氧化钛(TiO_2)薄膜,形成等离子体波导(PW)传感芯片.利用菲涅耳公式拟合实验测得的导模共振波长,得出TiO_2薄膜的多孔度约为0.589.基于光学互易定理仿真分析了置于介孔导波层中的电偶极子的拉曼辐射角分布,结果表明:辐射到衬底中的拉曼光包含沿导模共振角辐射的定向信号和辐射角小于全反射角的非定向信号;前者需借助棱镜耦合器才能被探测到,后者可从芯片背面直接被探测到;从导波层直接辐射到空气中的拉曼光称为背向信号,它的角分布呈发散式,几乎不受棱镜耦合器影响;定向信号的最大功率值远大于非定向信号和背向信号的相应值.实验研究了吸附于介孔导波层中的结晶紫分子的拉曼光谱,采用体光束激发方式探测到了定向、非定向和背向拉曼信号,定向信号强度的最大值是非定向信号的2倍多,在使用棱镜耦合器前后测得的背向信号强度几乎不变. 相似文献
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本文提出测量单模波导参数的新方法.用棱镜耦合器测量两种偏振基导模和基漏模的模折射率,并由相应的四个模方程确定单模波导参数.其测量精度优于纯导模测量.用这种方法测量了单模玻璃波导参数,并对误差来源作了理论分析. 相似文献
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《Optics Communications》1987,64(1):31-35
We investigate how bulk losses of the thin film waveguide core influence the propagation constants of the modes of an asymmetric slab waveguide. Film absorption of a few hundreds inverse centimeters causes measurable shifts of the effective refractive indices, particularly for modes of higher order. We evaluate the error, that would be introduced into measurements of the refractive index and film thickness by the prism coupler method, if existing film losses were to be ignored. 相似文献
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Xiangmin Liu Pengfei Zhu Zonglin Yan Jiangwen Wu Qingfen Yang 《Optics Communications》2008,281(2):273-277
The accurate reflection coefficient of prism waveguide coupler that takes coherence property of incident light into account is obtained at first. Based on the reflection coefficient, the effect of coherence property of incident light on prism coupling is discussed in this work. It is shown that extra damping in waveguide caused by the coherence property is larger for high-order resonant mode than that for low-order mode. For 100 fs Gaussian pulses incidence, the reflected spectra at different resonant modes are obtained theoretically and experimentally, which show that coherence property has a strong effect on prism coupling at high-order modes. 相似文献
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We report a novel method for enhancing near-field nanophotolithography using negative-refractive-index slabs. In our method,
a negative-refractive-index-metal film (NIF) is attached to the plane surface of an aplanatic solid immersion lens (SIL),
and the polymer layer is coated on the negative-refractive-index film. The intensity of the transmitted light is enhanced
by the surface plasmon polaritons excited in the NIF-polymer composite layer. The numerical results based on the vector diffraction
theory show that under the illumination of the SIL-NIF-polymer composite by a sharp focused radially polarized beam, the composite
configuration under investigation can substantially increase the spot intensity, suppress the spot expansion along the distance
from the interface, and improve the depth of focus, in comparison with conventional focusing systems using bare SILs. In the
case where a photoresist film is placed near the composite configuration, a subtle deep-etching pattern with high resolution
can be achieved. 相似文献
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A. B. Sotsky L. M. Steingart S. O. Parashkov L. I. Sotskaya 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(4):421-425
A criterion for selecting the best ranges for measuring the reflectivity of a prism coupler, based on minimizing the error in reconstructing the parameters of thin films using the least-square method, is proposed. The effectiveness of the criterion is demonstrated by solving the inverse optical problem for a SiOx film deposited on a silicon substrate as an example. 相似文献