提出了一种新型金属-绝缘体-半导体(MIS)混合表面等离子体结构,基于时域有限差分法验证了该结构在归一化频率范围(0.243-0.271)α/λ内具有明显的TM模式带隙。在二维光子晶体层移除或改变中间行空气孔半径构成线缺陷,形成混合波导结构1和2。分析表明入射光频率位于带隙内的光子能量被很好地局域在低折射率层中,且只能沿线缺陷传输。当入射波长为1550nm时,两种波导的传输距离分别为18.41pm、15.70μm,群速度极值分别为0.186c、0.166c,品质因数达到384.74、1042.50。此波导能通过光子晶体层的线缺陷控制低折射率层表面等离子体(SPP)激光的传输路径,为波导器件的研究提供了有效的理论依据。
A new type of metal-insulator-semiconductor (MIS) hybrid surface plasmonstructure is proposed. It is verified that the structure has obvious TM mode band gap in the normalized frequency range of (0.243-0.271)α/λ. Line defect is formed by removing and changing the radius of air holes in the two- dimensional photonic crystal layer, and hybrid waveguide structure 1 and 2 are constituted. Analysis shows that the photon energy whose frequency is located in the bandgap is well confined in the low index layer and can only be transmitted along the line defect. When the incident wavelength is 1550 nm, the transmission distances of two waveguides are 18.41 tern, 15.70 μm, the group velocity extreme values are 0.186c, 0.166c, the quality factors axe 384.74, 1042.50, respectively. The waveguide can control the transmission path of low refractive index layer surface plasmon polariton (SPP) through the line defect of photonic crystal layer. It provides an effective theoretical basis for the research of waveguide devices.