含负折射率材料的光子晶体异质结构的能带

构造了(AnBm)s型正负折射率材料交替生成的一维异质结构光子晶体.由于传输矩阵法具有方法简单、计算量低和精确度好等优点,本文利用传输矩阵法来研究电磁波在这种结构中的传输特性.由透射谱可以看出,该结构的光子晶体具有宽窄不同的通带,且整个能带结构不敏感于周期数的变化,而敏感于晶格厚度和入射角的改变:随着晶格厚度的减小,禁带逐渐变宽,在原来的通带区逐渐形成多个禁带,通带区震荡的剧烈程度逐渐减弱;随着入射角的增加,在原来的通带区也会逐渐出现多个禁带,其中在低频区逐渐出现的禁带都比较窄,而在高频区则逐渐出现一个很宽的禁带,并且这个禁带随着入射角的增加而变宽,同时透射峰随入射角的增加而逐渐向低频移动.由此可以看出,这种光子晶体可以同时实现窄带滤波和宽带滤波的双重滤波功能.

Band Structures of Photonic Crystal Heterostructure Containing Negative Refraction Materials

A one-dimensional photonic crystal heterostructure in the form of (AnBm)8 is constructed Because of simplicity, low calculation amount and high accuracy, the transfer matrix is used to study the propagation properties of electromagnetic waves in this structure. It can be found from the transmission spectrum that there are some passbands with di旺"erent widths in the photonic crystal containing the above structur巴The full band structure is not sensitive to the change of periodicity, but is sensitive to various incident angles and the scale length of crystal lattice. With the decrease of the scale length of lattice, the bandgap increases and forms several new bandgaps in the original pa启sband gradually, hence the intensity of the passband becomes weaker 飞Nith the increase of the scale length of lattice, several new bandgaps are also formed gradually in the original passband. The bandgaps formed in the low frequency range are narrow. However, a large bandgap is formed in the high frequency range. This large bandgap lncreωes with the increase of the incident angle and its transmisson peak moves toward the low frequency range gradually with the increru弓e of the incident angle. The result shows that this photonic crystal can be used as both a narrow-band filter and a wide-band filter at the same time.