一维缺陷型光子晶体湿敏特性研究

Study on the Characteristics of Humidity Sensitive for One-dimensional Photonic Crystal with Defects

本文设计了一种含缺陷层的一维光子晶体,采用传输矩阵法研究了一维缺陷型光子晶体的光子禁带、缺陷峰与环境湿度之间的关系。环境湿度变化将致使构成一维缺陷型光子晶体的介质的折射率发生变化,而构成一维缺陷型光子晶体的介质的折射率变化将会引起一维缺陷型光子晶体的光子禁带与缺陷峰发生变化。本文研究了一维缺陷型光子晶体在TE模式和TM模式下其能带结构中的光子禁带、缺陷峰与环境湿度变化之间的关系。研究结果表明,TE模式和TM模式下,在0%RH^100%RH的湿度变化范围内,一维缺陷型光子晶体存在显著的双光子禁带,且两个光子禁带的起始波长、终止波长、禁带宽度及缺陷峰的中心波长都随环境湿度呈规律变化。

In this paper,a One-Dimensional(1-D)photonic crystal with defects is designed by using two-dimensional humidity sensitive nano materials,based on the unique optical properties of two-dimensional nano materials.The transmission characteristics of 1-D photonic crystal with defects and the relationship between the photonic band gap in the energy band structure and environmental humidity are studied,which provides theoretical preparation for the preparation of 1-D photonic crystal with defects humidity sensor.1-D photonic crystal with defects is composed of humidity sensitive medium.The result show that the refractive index of the humidity sensitive medium of 1-D photonic crystal with defects changes as the environmental humidity changes,which will cause to change of the transmission characteristics and band structure of 1-D photonic crystal with defects.That is,the change of environmental humidity will eventually lead the change of the transmission spectrum and photonic band gap in the band structure of 1-D photonic crystal with defects.And the transmission characteristics and the relationship between the photonic band gap in band structure and environmental humidity change of 1-D photonic crystal with defects in TE mode and TM mode,are studied by using the Transfer Matrix Method(TMM).The starting and termination wavelength of the first and second photonic bandgap,as well as central wavelength of defect peak drift towards the direction of the increasement of wavelengths with the increasing of environmental humidity.For the starting wavelength of the photonic band gap,the drift of the starting wavelength of the first and second photonic bandgap in TE mode are 35.7 nm and 22.7 nm respectively,and that of the first and second photonic bandgap in TM mode are 29.6 nm and 21.2 nm,respectively.For the termination wavelength of the photonic band gap,the drift of the termination wavelength of the first and second photonic band gap in TE mode are 17.9 nm and 12.9 nm respectively,and that of the first and second photonic bandgap in TM mode are 18.9 nm and 12.5 nm respectively.For the central wavelength of defect peak,the drift of central wavelength of defect peak in TE mode is 20.4 nm,and that in TM mode is 19.9 nm.The bandgaps of the first and second photonic bandgap are reduced gradually,and the reduction of the band gap width of the first and second photonic bandgap are different.In TE mode,the first and second photonic bandgap are reduced by 17.8 nm and 9.8 nm respectively.In TM mode,the first and second photonic bandgap are reduced by 10.7 nm and 8.7 nm respectively.Then,the starting wavelength,the termination wavelength,the band gap width of the first and second photonic band gap and the central wavelength of defect peak are basically proportional to the square of the environmental humidity.Thus,there are two photonic band gaps and defect peak in the band structure both in TE mode and TM mode for 1-D photonic crystal with defects designed in this paper.The transmission spectrum of 1-D photonic crystal with defects gradually moves to the direction of the increasement of wavelength,with the increasing of the environmental humidity in the range of 0%RH^100%RH.And the starting and termination wavelength of the first and second photonic band gap,as well as central wavelength of defect peak,also both drift to the direction of the increasement of wavelength as a whole.The drift of the first and second photonic band gap,as well as defect peak,are both proportional to the square of environmental humidity.