Optical bistability in plasmonic nanoparticles: Effect of size, shape and embedding medium

• Study of optical bistability in metallic cylindrical and spherical nanoparticles.
• Study of the dependence of optical bistability on the size and shape of plasmonic nanoparticles.
• Investigation of the effect of shell thickness and the embedding medium on the optical bistability.
• Investigation of the role of key parameters on the width of the bistability region and the bistable threshold.

We theoretically investigate the optical bistability, which one input signal allows two possible outputs, from single spherical/cylindrical nanoparticles and also nanoshells in the frame work of quasi-static formalism. It is shown that the bistability behavior greatly depends on several parameters such as the nanoparticle size, material and the surrounding dielectric environment. We demonstrated the width of the bistability region and also the bistable threshold depends on the geometrical parameters, and can be tuned by adjusting the size of nanoparticle, the shell thickness and the dielectric constant of the embedding medium. It is also shown that the optical bistable behavior depends strongly on the shape of plasmonic nanoparticles and nanoshells. However, these dependences of optical bistability of spherical/cylindrical nanoparticles and nanoshells on changing of their geometrical parameters can be used for realize optical switching and sensing purposes.