optical properties of au-ag bimetallic nanoparticles of different shapes for making efficient bimetallic-photonic whispering gallery mode hybrid microresonators

For the first time, we propose a bimetallic-photonic whispering gallery mode (wgm) hybrid microresonator for the detection and sizing of single protein molecules in real time. to optimize the sensitivity of hybrid microresonators, theoretical simulations have been carried out to understand the optical properties of different types of au-ag bimetallic nanoparticles such as solid nanospheres, dielectric core-bimetallic nanoshells, nanostars, and nanoprisms using lorenz-mie theory, aden-kerker theory, and finite element method (fem). the role of size and au-ag ratio on the optical properties of the nanospheres and nanoshells has been studied. in addition, the effect of the au-ag ratio on the optical properties of nanostars and nanoprisms has been investigated. the local electric field intensity enhancement values of bimetallic nanostructures of different shapes have been estimated using the fem. finally, the advantages of the bimetallic-wgm hybrid microresonator as compared to the monometallic-wgm hybrid microresonator have been explained in detail.