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利用表面等离激元短波长和近场增强效应的特性,用多束P偏振态相干光激发表面等离激元(SPPs),并优化干涉光刻的曝光参数,可获得高分辨率、高对比度周期性纳米结构.阐述了多束SPPs干涉法制备纳米光子晶体的原理,并得到了干涉场强度分布随光束增加的关系.随着干涉SPPs数目的增加,干涉场会复杂变化,对此进行了计算机模拟.模拟了三束SPPs和六束SPPs干涉的强度分布,并分析了调制技术干涉曝光结果,该方法适合光电子器件中大范围亚波长的周期性孔阵或点阵结构的制作以及纳米量级光子晶体的的制作,并可以有效降低制作成本. 相似文献
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用三光束干涉模型解释锥镜产生类贝塞尔光束 总被引:10,自引:10,他引:0
对高斯光束通过锥镜产生类似贝塞尔光束的环形光束进行了理论分析及实验研究.数值模拟过程中,基于相干光干涉理论,考虑到实际情况中锥尖不尖带来的影响,建立了三光束干涉的数学模型.模拟得到的光场分布与实验结果及基于菲涅尔衍射积分理论或空间光谱理论得到的零阶贝塞尔光束很接近.这种光场具有非衍射特性,可应用于新型光镊研究. 相似文献
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本文介绍了一种基于Wollaston棱镜角剪切和Savart偏光镜横向剪切组合的静态、紧凑型、高通量差分偏振干涉成像光谱技术.其显著特点是无运动部件,可同时获取目标正交偏振组分的干涉图和二维空间图像.干涉图经傅里叶变换和图像融合算法可得到正交偏振组分的偏振光谱图像,正交偏振光谱图像之和等效于传统强度光谱图像,正交偏振光谱图像之差称为差分偏振光谱图像.高对比度的差分偏振光谱不仅能刻画目标详细的表面形貌、纹理和结构信息,还可反演弹性散射粒子的尺度、浓度和折射率等信息.文中描述了差分偏振干涉成像光谱仪的原理结构,给出了干涉强度分布规律表达式,分析了完整干涉图和二维空间图像的数据获取模式.利用杨氏干涉模型对光通过Savart偏光镜后形成干涉直条纹的近轴关系进行了深入分析.利用光场衍射理论确定了光谱仪中准直透镜和成像透镜实现紧凑化的结构关系.计算机仿真模拟验证了方案的可行性.为偏振成像光谱仪的发展提供了一种新思路. 相似文献
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在大学物理中,光的干涉和衍射现象是描述光的粒子性和波动性非常常见的内容。那么光的干涉需满足相干条件,即两束光具有相同的偏振态、相同的频率和固定的相位差。因此,在标量衍射理论中,完全正交偏振的光不能够发生干涉现象。为拓展和探究正交偏振态下两束光相遇时光场的矢量变化,本文构建了基于马赫-曾德尔配置的正交偏振光(即正交线偏振和正交圆偏振)相干涉而产生的光场,利用检偏器检测光场的矢量特征及条纹分布情况。结果表明正交偏振光相干涉产生了周期性的矢量光场。该研究能够帮助学生更加直观的掌握波片及偏振片调制不同偏振态的光束并实现矢量光场的检测和分析。 相似文献
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非共面多光束干涉及其在制作周期性微结构中的应用(Ⅰ)--一般分析及二维周期结构 总被引:1,自引:1,他引:0
非共面多光束干涉可以在空间形成二维或三维周期性强度分布,从而被用来制作二维或三维光子晶体.本文将对此课题的相关物理基础进行较为系统的分析和讨论,为沟通基础物理与近代物理的联系,理解光子晶体这一重要的前沿课题从一个侧面打下基础.本文第一部分首先简要介绍了此领域的相关背景,然后给出非共面多光束干涉的一般分析,最后着重讨论了非共面三光束干涉所形成的二维周期性空间结构,包括结构类型、光束设计及偏振最佳化等问题. 相似文献
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《光子学报》2015,(10)
建立了多光束干涉光刻干涉场内光强分布的数学模型,仿真计算了双光束、三光束、四光束干涉曝光情况下,入射光束存在角度偏差以及各入射光强不同时的干涉图样,并与理想状态的模拟结果进行对比.结果表明:光束入射角度偏差主要影响干涉图样的形状和周期;入射光的光强不同是降低图形对比度的主要因素.利用402nm波长激光光源进行多光束干涉光刻实验.设定激光器输出功率32mW,每两束光夹角为16°,通过控制曝光、显影工艺,双光束干涉光刻产生周期为1.4μm的光栅、点阵和孔阵结构,三光束干涉光刻产生周期为1.7μm的六边形图形阵列.该模型可为利用干涉光刻技术制备微细周期结构,提高光刻图形质量,提供一定的理论参考. 相似文献
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理论研究了五能级系统中三光子共振非简并六波混频(NSWM) 由于中间能级加入耦合光场而产生的量子干涉效应. 分析了耦合光场对三光子共振NSWM信号以及频谱的影响. 研究发现, 在强耦合场作用下, NSWM的频谱出现了Autler-Townes分裂, 它反映的是两个缀饰态的能级, 量子干涉可以使NSWM信号被抑制或增强. 提出利用量子干涉对NSWM信号产生增强作用, 可以由耦合场产生的缀饰态代替原子固有能级, 成为三光子共振的中间态, 从而控制耦合场来选择三光子共振的中间态的位置. 相似文献
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Z. Wang Y. Zhang P. Li S. Sang C. Yuan H. Zheng C. Li M. Xiao 《Applied physics. B, Lasers and optics》2011,104(3):633-638
We report experimental observations of intensity modulation and spatial splitting of four-wave mixing (FWM) signal beams which
can be effectively controlled by the polarization states of the pumping laser beams. Due to the periodic change of the pumping
beam’s polarization states, the intensity of the FWM beam also evolves periodically. The periodic spatial splitting phenomenon
has been observed in both x- and y-directions. The cases with/without the dressing beams are compared. Such studies can be very useful in better understanding
the formation of spatial solitons and for signal processing applications, such as spatial beam splitter, routing, and switching. 相似文献
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Xin Jia Tianqing Jia Shian Zhang Zhenrong Sun Jianrong Qiu Zhizhan Xu 《Applied Physics A: Materials Science & Processing》2014,114(4):1333-1338
We report the fabrication of cross-linked micro/nanopatterns on ZnO by adjusting the femtosecond-laser polarizations of four-beam interference. The micro/nanopatterns are composed of two types of patterns with vertically oriented and horizontally oriented ripples, respectively. The relative locations, ablation depths and the nanoripple distributions of the two patterns can be manipulated by adjusting the laser polarizations. Theoretical calculations of the interference patterns indicate clearly that the micropatterns are determined by the interferential intensity patterns, while the nanopatterns depend on the interferential polarization patterns. The micro/nanopatterns have potential applications in micro-optical polarization diffraction elements by virtue of femtosecond-laser-induced anisotropy. 相似文献
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In view of the increasingly stronger available laser fields it is becoming feasible to employ them to probe the nonlinear dielectric properties of the vacuum as predicted by quantum electrodynamics (QED) and to test QED in the presence of intense laser beams. First, we discuss vacuum-polarization effects that arise in the collision of a high-energy proton beam with a strong laser field. In addition, we investigate the process of light-by-light diffraction mediated by the virtual electron-positrons of the vacuum. A strong laser beam “diffracts” a probe laser field due to vacuum polarization effects, and changes its polarization. This change of the polarization is shown to be in principle measurable. Also, the possibility of generating harmonics by exploiting vacuum-polarization effects in the collision in vacuum of two ultra-strong laser beams is discussed. Moreover, when two strong parallel laser beams collide with a probe electromagnetic field, each photon of the probe may interact through the “polarized” quantum vacuum with the photons of the other two fields. Analogously to “ordinary” double-slit set-ups involving matter, the vacuum-scattered probe photons produce a diffraction pattern, which is the envisaged observable to measure the quantum interaction between the probe and strong field photons. We have shown that the diffraction pattern becomes visible in a few operating hours, if the strong fields have an intensity exceeding 1024W/cm2. 相似文献
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Photofabrication of periodic microstructures in azodye-doped polymers by interference of laser beams 总被引:4,自引:0,他引:4
Volume holographic gratings and two-dimensional periodic microstructures in azodye-doped polymethylmethacrylate were fabricated,
respectively, by interference of two coherent beams of a femtosecond laser and by interference of three coherent beams of
a nanosecond laser. The dependence of the first-order Bragg diffraction efficiency and the photoinduced refractive-index modulation
of the gratings on the intensity of the writing light was investigated. The measurements of the absorption spectra before
and after irradiation with the writing light suggest that the photoinduced gratings were refractive-index-modulated gratings,
which arose from a photoinduced decomposition reaction of the azodye molecules through multiphoton absorption. In the experiments
involving the interference of three beams, the period of the two-dimensional periodic microstructures was changed by adjusting
the angle between the three writing beams.
Received: 10 July 2002 / Revised version: 5 September 2002 / Published online: 20 December 2002
RID="*"
ID="*"Corresponding author. Fax: +81-774/955206, E-mail: jhsi@photon.jst.go.jp 相似文献
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Two-dimensional periodic hexagon lattice is fabricated on silica glass by the interference of three non-coplanar beams originating from a single femtosecond laser pulse. The Atom Force Microscopy (AFM) characterizations indicate the elongation ratio R of periodic hexagon lattice can be conveniently controlled by changing colliding angles of the three beams and the angles difference. Controllable formation of periodic hexagon lattice on glass could be well interpreted by the theoretical simulation based on three-dimensional intensity distribution formed by the spatial interference of three non-coplanar beams. 相似文献
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采用单电子模型和经典辐射理论分别对低能和高能电子在线偏振激光驻波场中的运动和辐射过程进行了研究. 结果表明: 垂直于激光电场方向入射的低速电子在激光驻波场中随着光强的增大, 逐渐从一维近周期运动演变为二维折叠运动, 并产生强的微米量级波长的太赫兹辐射; 高能电子垂直或者平行于激光电场方向入射到激光驻波场中, 都会产生波长在几个纳米的高频辐射; 低能电子与激光驻波场作用中, 激光强度影响着电子的运动形式、辐射频率以及辐射强度; 高能电子入射时, 激光强度影响了电子高频辐射的强度, 电子初始能量影响着辐射的频率; 电子能量越高, 产生的辐射频率越大. 研究表明可以由激光加速电子的方式得到不同能量的电子束, 并利用电子束在激光驻波场的辐射使之成为太赫兹和X射线波段的小型辐射源. 研究结果可以为实验研究和利用激光驻波场中的电子辐射提供依据. 相似文献
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The contrast of interference pattern formed by two circularly polarized waves and by a linearly polarized wave and a circularly polarized one is discussed. The results are compared with that by two linear beams. It shows that the use of circular light in holographic fabrication of three-dimensional periodic microstructures may remove the necessity of beam ratio and polarization optimization needed in the interference of three linear noncoplanar beams and improve the uniform contrast of resultant pattern simultaneously. 相似文献
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Mützel M Tandler S Haubrich D Meschede D Peithmann K Flaspöhler M Buse K 《Physical review letters》2002,88(8):083601
In atom lithography with optical masks, deposition of an atomic beam on a given substrate is controlled by a standing light-wave field. The lateral intensity distribution of the light field is transferred to the substrate with nanometer scale. We have tailored a complex pattern of this intensity distribution through diffraction of a laser beam from a hologram that is stored in a photorefractive crystal. This method can be extended to superpose 1000 or more laser beams. The method is furthermore applicable during growth processes and thus allows full 3D structuring of suitable materials with periodic and non-periodic patterns at nanometer scales. 相似文献