Opto-electromagnetic Responses of Tamm Plasmon Polariton Modes in a Symbiotic Dual-Metallic architecture

We report a Tamm plasmon polariton (TPP) arrangement whose design consists of a thin Silver (Ag) film which is the plasmon-active metal and lies adjacent to the distributed Bragg Reflector (DBR) structure. The DBR consists of periodically stratified layers of Ta 2 O 5 and SiO 2 . TPP modes are excited through normal incidence using a white light source and we have obtained the corresponding reflectivity spectrum as a function of wavelength. The excitation spectrum is characterized by a sharp and distinguishable reflectivity dip within the photonic band-gap of DBR. Extending this version of the idea, we have replaced the single plasmon-active metal by two metals to overrule the drawbacks of these single metals concerning their physiochemical properties like propagation length, chemical stability, and various losses during propagation of the plasmon wave, etc. Hence, we have obtained the reflectivity characteristics for different bimetallic architecture supporting TPP resonances. Thereafter, we have also obtained the Full Width at Half Minimum (FWHM) wavelengths and Quality Factor (Q-Factor) characteristics as a function of metal thickness for two different plasmon active metallic combinations, where the total bimetallic thickness remains constant. The shortcomings of a particular metal are nullified by the presence of the other metal with it. Such an arrangement is envisioned for the fabrication of nanoscale smart devices like optical and biosensors having potential applications in social welfare domain like monitoring the levels of food adulteration and food safety, etc.