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近年来,有两种人工材料,即光子晶体和左手材料在电磁波传输方面发挥着重要作用。光子晶体是周期性结构排列的介电结构,存在波的能带结构,在光学器件方面有着许多重要的应用。新型人工左手材料同时呈现负介电常数和负磁导率,有着许多与传统介质不同的反常电磁波特性,具有广泛的应用前景。采用传递矩阵的方法研究了由正折射率材料和负折射率材料交替排列组成的一维光子晶体结构的透射谱,并对其能带结构和色散关系进行分析。这种正负折射率光子晶体不仅存在一般的布拉格禁带,还存在低频共振禁带。在这种系统中存在非局域化态,同时由于低频禁带的存在,使得这种结构有更小的局域化长度,更适合观察局域化现象。
In recent years, two kinds of artificial materials, namely photonic crystals and left-handed materials, play an important role in electromagnetic wave transmission. Photonic crystals are periodic structure of the dielectric structure, the existence of wave band structure, in the optical device has many important applications. The new artificial left-handed material exhibits negative dielectric constant and negative magnetic permeability at the same time, and has many unusual electromagnetic wave characteristics different from the traditional medium, which has a wide range of application prospects. The transmission spectra of a one-dimensional photonic crystal structure consisting of alternating materials of positive refractive index and negative refractive index were investigated by transfer matrix method. The relationship between the band structure and dispersion was analyzed. The positive and negative refractive index photonic crystals not only exist in the general Bragg band gap, there are low frequency resonance forbidden band. In this system, there exists a nonlocalized state. At the same time, due to the existence of the low-frequency forbidden band, this structure has a smaller localization length and is more suitable for observing the localization phenomenon.