一维光子晶体的光子带隙研究

通过改变一维光子晶体的周期排列常数、两种介质的折射率比观察了电磁波在光子晶体中的光子带隙(PBG)行为.当两种介质的排列周期常数a:b=1:1和1:2时,发现光子晶体在可见光区存在一个很宽的频率截止带,即光子带隙区.另外,当两种介质的介电常数比εα:εb小于1:5,在可见光区无光子带隙存在;而当该比率大于1:5时则出现一个很宽的光子带隙.说明两种介质的介电常数比对光子带隙的影响很大,该比例越大,越容易获得光子带隙.

Study on the photonic band gap of one dimensional photonic crystals

The photonic band gap (PBG) of photonic crystals has been studied through electromagnetic field propagation in one dimensional (1 D) periodic medium. The transmission dependence of the frequency of electromagnetic wave has been investigated by changing the periodic constant and the ratio of dielectric constants. A large stop frequency band in the visible region has been obtained when the periodic a = b = 1:1 and 1:2, respectively, which indicates that there exists a large PBG in the region. In addition, we found there is no PBG in the visible light region when the ratio of the dielectric constants is smaller than 1:5, but a large PBG band appears when the ratio is larger 1:5. which shows that PBG is strongly affected by the dielectrics index contrast of two mediums. The larger the difference contrast of the dielectric constants, the easier it is to obtain the PBG.