共查询到19条相似文献,搜索用时 109 毫秒
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反射式多通道滤光片在光学通讯、光学成像、遥感高光谱等方面有着重要的应用。利用含缺陷一维光子晶体独特的带隙特性,依据其相应的能带理论,设计了一种由金属和介质组成的反射式多通道滤光片。这种滤光片通道的工作范围由光子带隙理论计算得到,通道个数由"光子晶体"缺陷的周期数决定,通道的位置利用等效相位厚度的方法确立。相对于传统的以经验为主的反射式多通道滤光片设计方法,这种基于光子晶体的带隙理论的设计能够从"光子"的角度给出此类反射式滤光元件的设计思路和理论解释。 相似文献
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光子晶体是由两种或两种以上不同介电常数材料所构成的周期性光学纳米结构.光子晶体结构可分为一维、二维和三维,其中二维光子晶体已成为研究的热点.可调带隙的二维光子晶体可以设计出新型的光学器件,因此,对它的研究具有重要的理论意义和应用价值.本文提出的二维新型函数光子晶体可以实现光子晶体带隙的可调性.所谓二维函数光子晶体,即组成它的介质柱的介电常数是空间坐标的函数,它不同于介电常数为常数的二维常规光子晶体.二维函数光子晶体是通过光折变非线性光学效应或电光效应使介质柱的介电常数成为空间坐标的函数.运用平面波展开法给出了TE和TM波的本征方程,由傅里叶变换得到二维函数光子晶体介电常数ε(r)的傅里叶变换ε(G),其傅里叶变换比常规二维光子晶体的复杂.计算发现当介质柱介电常数为常数时,其傅里叶变换与常规二维光子晶体的相同,因此二维常规光子晶体是二维函数光子晶体的特例.在此基础上具体研究了二维函数光子晶体TE波和TM波的带隙结构,其介质柱介电常数函数形式取为ε(r)=k·r+b,其中k,b为可调的参数.并与二维常规光子晶体TE波和TM波的带隙结构进行了比较,发现二维函数光子晶体与二维常规光子晶体TE波和TM波的带隙结构有明显的区别,二维函数光子晶体的带隙数目、位置以及宽度随参数k的变化而发生改变.从而实现了二维函数光子晶体带隙结构的可调性,为基于二维光子晶体的光学器件的设计提供了新的设计方法和重要的理论依据. 相似文献
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设计了用反Opal结构光子晶体测量透明液体折射率的实验.根据布拉格公式推导了用反Opal光子晶体测量透明液体折射率的公式.利用紫外-可见分光光度计分别测得光子晶体处于空气和透明液体中的透射谱,由透射谱分别确定光子晶体处于2种介质中的禁带中心波长,将中心波长代入测量公式即可得到透明液体折射率.实验测量了水和甘油的折射率,得到了与公认值相吻合的结果. 相似文献
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光子晶体超窄带滤波器 总被引:35,自引:13,他引:22
本文利用光学传输矩阵法研究了一种类似于谐振腔结构的光子晶体.研究发现在这种光子晶体的光子带隙的中央存在一个极窄的透光窗口,窗口的宽度在红外波段1500nm附近可以做到0.0001nm以下,窗口内的透光率峰值可以接近100%,窗口以外的区域的透光率可以做到0.01%以下.通过改变所研究结构中的周期厚度、中间夹层厚度、两边光子晶体的周期重复数和波的入射角可以改变窄带透过窗口的位置和窄带的宽度.这种光子晶体可以用来制作超窄带滤波器,有望在光通信超密度波分复用技术和光学信息精密测量技术当中获得应用. 相似文献
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V. A. Tolmachev 《Optics and Spectroscopy》2017,122(4):646-660
The theoretical and experimental investigations of photonic band gaps in one-dimensional photonic crystals created by micromatchining silicon, which have been performed by the author as part of his doctoral dissertation, are presented. The most important result of the work is the development of a method of modeling photonic crystals based on photonic band gap maps plotted in structure–property coordinates, which can be used with any optical materials and in any region of electromagnetic radiation, and also for nonperiodic structures. This method made it possible to realize the targeted control of the optical contrast of photonic crystals and to predict the optical properties of optical heterostructures and three-component and composite photonic crystals. The theoretical findings were experimentally implemented using methods of micromatchining silicon, which can be incorporated into modern technological lines for the production of microchips. In the IR spectra of a designed and a fabricated optical heterostructure (a composite photonic crystal), extended bands with high reflectivities were obtained. In a Si-based three-component photonic crystal, broad transmission bands and photonic band gaps in the middle IR region have been predicted and experimentally demonstrated for the first time. Si–liquid crystal periodic structures with electric-field tunable photonic band-gap edges have been investigated. The one-dimensional photonic crystals developed based on micromatchining silicon can serve as a basis for creating components of optical processors, as well as highly sensitive chemical and biological sensors in a wide region of the IR spectrum (from 1 to 20 μm) for lab-on-a-chip applications. 相似文献
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全固态光子带隙光纤由于其独特的带隙和色散特性以及易于和传统光纤熔接的优势,引起了国内外研究人员的广泛关注.本文采用等离子体化学气相沉积工艺结合堆叠拉制法制备了全固态光子带隙光纤,并运用频域有限差分法模拟了其损耗和色散特性.该光纤1550 nm处有较低损耗且单模传输,计算得到1550 nm处的有效模场面积和色散分别为191.81μm2和16.418 ps/(km·nm),在测试范围1500—1650 nm内损耗小于0.15 dB/m.结合实验结果,对光纤参数做了进一步模拟优化. 相似文献
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G. J. Pert 《Contemporary Physics》2013,54(4):303-306
In the first part of this introductory review we outline the developments in photonic band gap materials from the physics of photonic band gap formation to the fabrication and potential applications of photonic crystals. We briefly describe the analogies between electron and photon localization, present a simple model of a band structure calculation and describe some of the techniques used for fabricating photonic crystals. Also some applications in the field of photonics and optical circuitry are briefly presented. In the second part, we discuss the consequences for the interaction between an atom and the light field when the former is embedded in photonic crystals of a specific type, exhibiting a specific form of a gap in the density of states. We first briefly review the standard treatment (Weisskopf?–?Wigner theory) in describing the dynamics of spontaneous emission in free space from first principles, and then proceed by explaining the alterations needed to properly treat the case of a two-level atom embedded in a photonic band gap material. 相似文献
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The tunable two-dimensional photonic crystals band gap, absolute photonic band gap and semi-Dirac point are beneficial to designing the novel optical devices. In this paper, tunable photonic band gaps structure was realized by a new type two-dimensional function photonic crystals, which dielectric constants of medium columns are functions of space coordinates. However for the two-dimensional conventional photonic crystals the dielectric constant does not change with space coordinates. As the parameter adjustment, we found that the photonic band gaps structures are dielectric constant function coefficient, medium columns radius, dielectric constant function form period number and pump light intensity dependent, namely, the photonic band gaps position and width can be tuned. we also obtained absolute photonic band gaps and semi-Dirac point in the photonic band gaps structures of two-dimensional function photonic crystals. These results provide an important theoretical foundation for design novel optical devices. 相似文献
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一维光子晶体禁带的展宽 总被引:7,自引:6,他引:7
作为一维光子晶体的应用基础,一维光子晶体的禁带是研究的重点。通过传输矩阵的方法分析了一维光子晶体禁带的特性,讨论了影响带宽的因素。说明了相对带宽对光子晶体设计的重要性。在这个基础上讨论了扩展一维光子晶体带宽的方法,提出了在角域范围内对光子晶体进行叠加的方法,为设计制造一维光子晶体提供了一种行之有效的方法。分别对2个、3个和4个晶体的叠加进行了分析,最后计算了所设计的合成晶体的反射率。其中4个晶体的叠加,相对带宽达到57.52%,极大地展宽了一维光子晶体的禁带,从而证明利用角域的叠加来展宽一维光子晶体的禁带是非常有效的。 相似文献
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光子晶体由于具有光子带隙和光子局域等一系列优异的光学特性而受到了人们广泛的关注。由于采用胶体颗粒自组装法制备光子晶体制备工艺简单,所需要的费用也较低,因此已成为制备可见光至红外波段三维光子晶体的一种简便有效的方法。采用垂直沉积法制得了三维光子晶体薄膜,并用扫描电子显微镜和紫外-可见光-近红外分光光度计对其显微结构和光学特性进行了详细的研究。结果表明,自组装薄膜在三维方向上都具有有序结构,其密排面平行于载波片的表面。制备的光子晶体薄膜具有明显的光子带隙特性,带隙中心波长为956nm。研究了带隙中心波长同入射线与密排面法线夹角之间的变化关系,其结果与理论值吻合得很好。 相似文献