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1、Photonic crystalPhotonic crystals are periodic optical nanostructures that are designed to affect the motion of photons in a similar way that periodicity of a semiconductorcrystal affects the motion of electrons. Photonic crystals occur in nature and in various forms have been studied scientifically
2、 for the last 100 years.光子晶体具有周期性光学纳米结构，光子晶体对光子的作用与半导体晶体对电子的作用具有相同的效果。光子晶体具有天然和多种形式，对光子晶体研究已经有百年历史。IntroductionPhotonic crystals are composed of periodic dielectric or metallo-dielectric nanostructures that affect the propagation of electromagnetic waves (EM) in the same way as the periodic potentia
3、l in a semiconductor crystal affects the electron motion by defining allowed and forbidden electronic energy bands.光子晶体由周期性电解质或者金属电解质组成的纳米结构，光子晶体对传播电磁波的作用与周期性半导体对电子运动形成的通带和禁带作用具有相同形式。Essentially, photonic crystals contain regularly repeating internal regions of high and low dielectric constant. 实质上，
4、光子晶体内部包括规则性和重复性的高低不同的介电常数。Photons (behaving as waves) propagate through this structure - or not - depending on their wavelength. 具有波动性的光子在光子晶体内传播与否主要取决于光子的波长。Wavelengths of light that are allowed to travel are known as modes, and groups of allowed modes form bands. 允许光波长通过被人认为是模式，多个模式组成一个带。Disallowe
5、d bands of wavelengths are called photonic band gaps. 不允许波长通过的被称为光子带隙。This gives rise to distinct optical phenomena such as inhibition of spontaneous emission, high-reflecting omni-directional mirrors and low-loss-waveguiding, amongst others.光子带隙产生了独特的光学现象，例如：抑制自发发射，全方位高度镜像反射，和低耗波导。Since the basic p
6、hysical phenomenon is based on diffraction, the periodicity of the photonic crystal structure has to be of the same length-scale as half the wavelength of the EM waves i.e. 350 nm (blue) to 700 nm (red) for photonic crystals operating in the visible part of the spectrum - the repeating regions of hi
7、gh and low dielectric constants have to be of this dimension. 因为光学散射这一物理现象，光子晶体的周期性尺度限定于电磁波波长 350（蓝光）700nm （红光）的一半，光子晶体高低介电常数周期重复被定义为可见光谱区域。This makes the fabrication of optical photonic crystals cumbersome and complex.由于以上的特殊光学性质，光子晶体的制备十分复杂和难以实现。History of photonic crystalsAlthough photonic crysta
8、ls have been studied in one form or another since 1887, the term photonic crystal was first used over 100 years later, after Eli Yablonovitch and Sajeev John published two milestone papers on photonic crystals in 1987.12尽管光子晶体研究在 1887 年就已经开始，但是自 1987 年， Eli Yablonovitch 和 Sajeev John 对光子晶体研究以来，“光子晶体
9、”这一术语才有100 年历史。Before 1987, one-dimensional photonic crystals in the form of periodic multi-layers dielectric stacks (such as the Bragg mirror) were studied extensively.在 1987 年前，周期性多层电解质堆积的一维光子晶体已被广泛研究。 Lord Rayleigh started their study in 1887,3 by showing that such systems have a one-dimensional
10、photonic band-gap, a spectral range of large reflectivity, known as a stop-band. 1887 年，Rayleigh 报道具有一维光子带隙结构的反射光谱研究，该带隙被定义为止带。Today, such structures are used in a diverse range of applications; from reflective coatings to enhancing the efficiency of LEDs to highly reflective mirrors in certain lase
11、r cavities (see, for example, VCSEL). 直到今天，该结构的已被广泛应用到多个领域，通过添加反射层加强了二极管在激光反射腔内反射效率。A detailed theoretical study of one-dimensional optical structures was performed by Vladimir P. Bykov,4 who was the first to investigate the effect of a photonic band-gap on the spontaneous emission from atoms and mo
12、lecules embedded within the photonic structure. Vladimir P. Bykov 对一维光学结构做了仔细研究，第一次对原子和分子嵌入光子结构后光子带隙对自发辐射的影响。Bykov also speculated as to what could happen if two- or three-dimensional periodic optical structures were used.5 Bykov 同时也研究如果二维和三维光学结构将会发生什么现象。 The concept of three-dimensional photonic cr
13、ystals was then discussed by Ohtaka in 1979,6 who also developed a formalism for the calculation of the photonic band structure. Ohtaka 于 1979 年讨论了三维光子结构，推到了计算光子带隙结构的公式。However, these ideas did not take off until after the publication of two milestone papers in 1987 by Yablonovitch and John. 然而，三维光子
14、结构制备及延续直到 1987 年 Yablonovitch and John 发表两篇具有里程碑的文章后才得以延续。Both these papers concerned high dimensional periodic optical structures photonic crystals. 两篇文章涉及到多维周期性光学结构光子晶体。Yablonovitchs main motivation was to engineer the photonic density of states, to control the spontaneous emission of materials em
15、bedded within the photonic crystal; Yablonovitch 致力于光子态密度研究，从而控制嵌入光子晶体材料的自发辐射。Johns idea was to use photonic crystals to affect the localisation and control of light. John 致力于应用光子晶体作用和控制光传播。 The structure that Yablonvitch was able to produce involved drilling a triangular array of cylindrical holes
16、in layers of transparent material, where the holes of each layer are placed on top of the remaining material in the layer below, the structure repeats every 4 layers, and was modeled after an inverse diamond structure, and today is known asYablonovite.After 1987, the number of research papers concerning photonic crystals began to grow exponentially. 自 1987 年后，关于光子晶体研究的论文考试指数增长。However, due to the difficulty of actually fabricating these structures at optical
