基于光子晶体光学塔姆态的耦合分析,提出了一种含金属插层的折射率传感结构。对该光子晶体结构中光学塔姆态的形成机理进行了分析,并调整金属插层的厚度来实现两个光学塔姆态的耦合。建立缺陷峰波长与待测溶液折射率的关系模型,并分析其折射率传感特性。通过对光子晶体周期数和入射角度的讨论,可以得到,增加光子晶体周期数(或入射光的入射角度)可减小缺陷峰的半峰全宽(FWHM),从而提高传感器的灵敏度和折射率的分辨率。以乙二醇为待测样本,可得该传感器的灵敏度为445.45 nm/RIU(折射率单元),品质因数(Q值)可达1259.45。该传感器结构具有制备工艺简单和结构紧凑等优点,可为高Q值和高灵敏度折射率传感器的设计提供一定的理论参考。
Based on the coupling analysis of the optical Tamm states in the photonic crystal, a refractive index sensing structure containing metal inset layer is proposed. The formation mechanism of optical Tamm state is analyzed and the suitable thickness of the metal is chosen to realize the coupling of two optical Tamm states. The relationship model between the reflection peak wavelength and the refractive index of the sample solution is established, and its refractive index sensing characteristics are discussed. Through the discussion of the periodicity and the incident angle of the photonic crystal, it shows that the full width at half maximum (FWHM) can be reduced by increasing the periodicity (or the incident angle), which can improve the sensitivity of the sensor and the resolution of the refractive index obviously. The ethylene glycol is adopted as the sample detected, the sensitivity of the refractive index sensing structure is about 445.45 nm/RIU, and the quality factor (Q value) can attain to 1259.45. The sensor structure has several advantages such as simple preparation and compact structure, which can provide some theoretical references for the design of high Q value and high sensitivity refractive index sensors.