Study Of Micro Nano Photonic Devices Based On Optical Tamm States

Optical Tamm states(OTS,also known as Tamm plasmons),were lossless interface mode which were proposed by AV Kavokin in 2005.OTS were recently discovered at the interface between a metal film and a one-dimensional photonic crystal(PhC).In this paper,several micronano photonic devices are designed based on the OTS characteristics.The main research contents are as follows:An efficient nanoscale unidirectional transmission device at telecommunication wavelength is proposed,which is made up of a metal-dielectric-metal(MDM)waveguide.The waveguide core is asymmetric and comprises of a one-dimensional photonic crystal(PhC),a thin Ag film and adielectric layer in a sequential order.The unidirectional propagation is realized by combining thephotonic bandgap effect and the asymmetric excitations of Tamm plasmon polaritons(TPPs)on two sides of the PhC,i.e.TPPs are only excited at the interface between the PhC and the Ag core film,and not excited on the other facet of the PhC.It is demonstrated by numerical simulations that the maximum positive transmittance(87%)and a high transmission contrast ratio(1250)are achieved in this structure.A highly sensitive refractive index sensor and an efficient unidirectional absorber are designed based on the properties of the quasi optical Tamm states.The sensor structure is composed of MDM waveguide structure,a thin Ag film and the periodic double toothed structure of the Bragg gratingare introduced into the waveguide core.The TM polarized light is incident from a thin Ag film.When the phase matching condition is satisfied,OTS of a thin Ag film and the Bragg gratinginterface is effectively excited.The excitation wavelength of the quasi optical Tamm state changes with the change of the refractive index of the measured objects in the Bragg grating.The refractive index sensing function can be achieved.The FHWM of the sensor is 14 nm and sensitivity is1500nm/RIU.The structure of the absorber is composed of MDM waveguide structure,a thin Agfilm and single side branch structure in the waveguide core.Based on the local field enhancementcharacteristic of the quasi optical Tamm state at the interface between a thin Ag film and the singleside branch,the unidirectional absorption rate of the absorber is 89.948% and the absorption ratio is0.83.A high sensitive refractive index sensor is designed based on double Fano resonance.The structure is composed of a MDM waveguide structure.In the waveguide core,the upper rectangularcavity,the lower rectangular cavity and a thin Ag film are introduced.Because the narrow spectrumformed by the upper and lower cavity is superposed with the wide spectrum interference formed by the MDM-Ag structure,the transmission line is Fano linear.It is found that multiple rectangularresonances are added to the structure to form multiple Fano resonances.Through the coupling of two Fano,the transmitted spectrum lines have narrow line width and high sensitivity.Finally,The FHWM of the sensor is 14 nm and sensitivity is 1200nm/RIU.