Theory And Application Of Optical Tamm States

Optical Tamm states?OTS?are lossless surface states which were proposed by AV Kavokin in 2005.Such surface wave is mainly exist in the PC heterojunction or the interface between a metal and a distributed Bragg reflector without any special incident angle and dispersion adjustment elements which can be directly excited by TM or TE polarized light.OTS have a variety of excellent features such as low loss,local field enhancement effect,narrow bandwidth and so on.Based on the advantage of OTS,a new method to enhance the light transmission of a single nano-slit is proposed in this paper.What's more,a multi-channel and tunable Tamm plasma absorber is also designed and discussed.The main research contents are as follows:Firstly,based on the physical mechanism and dispersive properties of OTS,a novel method and the related structure are proposed to effectively enhance the EOT in a single nano-slit.This structure is made up of a silver film on a distributed Bragg reflector?DBR?,where a single nano-slit is imbedded in the silver film.The OTS and the surface plasmon polaritons?SPPs?in the nano-slit can intercoupling and leads to the appearance of a hybrid state under the illumination with a TM polarized light by means of transfer matrix method and finite element method.When the wave-vectors between the OTS and the SPPs modes are matched,due to the local field enhancement of the TPPs mode,the excitation efficiency of SPPs can be improved significantly.Furthermore,utilizing the quasi Fabry-Pérot?F-P?resonance in the nano-slit,a high light transmission through the single nano-slit can be achieved.The study elucidate that a thickness of the silver film of 100 nm and a width of the nano-slit of 11 nm can enhance the light transmission through the single nano-slit by about 16 times in comparison to a single nano-slit in a silver film on the TiO₂ substrate.The proposed method has potential applications in the Optical non-destructive testing,the polariton lasers,the magnetic filter and other related areas.Secondly,a Tamm plasma absorber with high absorption,multi-channel and tunable absorption peak position is designed based on the coupling mode of OTS.This kind of absorber consists of a Metal-Dielectric-Metal?MDM?waveguide and a metal-DBR-metal intercalation-DBR-metal within the waveguide.It makes use of the SPPs into the waveguide and the OTS on the interface between a metal and a distributed Bragg reflector so that the incident light is localized at the interface between the dielectric and the metal,thereby suppressing the reflection of light and achieving a strong absorption of light.The absorption spectrum characteristics are analyzed with the finite element method?FEM?.On account of the local field enhancement effect of SPPs in MDM and the coupling of OTS in waveguide,simulation results show that the multi-channel absorber can realize perfect absorption,the absorption rate is over 98% and the minimum of Full Width Half Maximum?FWHM?is up to 8nm.By changing the width of MDM waveguide,the periodicity of DBR on both sides of the metal intercalation and the thickness of the metal intercalation,the absorption peak position can be tunable.Further studies show that the increasing of the number of metal intercalations n in DBR can increase the number of absorption peaks N,their relationship can be expressed as N= 2*?n+1??where n?0?.This Tamm plasma absorber helps to improve the sensitivity of biosensors and multi-wavelength photodetectors.The proposed structure can be widely applied in the hazardous substance detection,hyperspectral multi-frequency imaging,coherent thermal radiation,and stealth technology.