级联对称结构光子晶体的透射谱特性

Transmission Spectrum Characteristics of Photonic Crystal with Cascaded Symmetrical Structure

利用传输矩阵法理论,研究级联对称结构一维光子晶体的透射谱特性,结果表明:当不同厚度的A、B介质构成单级联光子晶体(AnBn)10时,光子晶体透射谱中出现带宽较宽的禁带,且禁带随介质层物理厚度的增大向长波方向移动(蓝移现象);当光子晶体为单级联对称结构(AnBn)5(BnAn)5时,禁带中出现1条透射率为100%的精细透射峰,具有对称结构光子晶体的透射谱特征,且禁带及禁带中的单透射峰随介质层物理厚度的增大也出现蓝移现象;当级联数目增多构成多级联对称结构光子晶体(A1B1)5(A2B2)5…(AnBn)5(BnAn)5…(B2A2)5(B1A1)5时,透射谱中出现带宽很宽的禁带,且禁带随介质层物理厚度的增大向长波方向展宽,而短波一侧则出现波长间隔密集的精细透射峰。级联对称结构光子晶体的透射谱特性,为设计制备光学全反射器件提供理论依据。

The transmission spectrum characteristics of photonic crystal with cascaded symmetrical structure are studied by transfer matrix method. It shows that when media A, B with different physical thickness constitute a single cascade photonic crystal （ AnBn ） 10, the wide band gap appears in the transmission spectrum of photonic crys- tal, and the band gap shift to long wave direction （the blue -shift） with the increase of the physical thickness of the dielectric layer. When the photonic crystal is a single cascade symmetric structure （AnBn）5（BnAn）5, there is a fine transmission peak appearing （the transmittance is 100% ） in the ban gap, having the same characteristic as the transmission spectrum of the symmetrical structure photonic crystal, and the band gap and the single transmis- sion peak are also appearing blue - shift with increase of the thickness of the dielectric layer. When the increasing number of cascades forms the multi cascades symmetrical structure photonic crystal （ A1 B1 ） 5 （ A2B2 ） 5... （ AnBn ） 5 （BnAn）5... （B2A2）5（B1A1）5, the wide band gap appears in the transmission spectrum. The band gap is broad- ened to the long wave direction, and in the short wave side there is the frequency interval intensive transmission peak appearing with the increase of the thickness of the dielectric layer. The properties of the cascade symmetrical structure photonic crystal can provide theoretical basis for the design and fabrication of optical total reflection de- vices.