Background: 'Plasmonics’ dealing with localized surface plasmon resonances in metal nanoparticles
(nanostructures) and planar metal-dielectric interfaces is a rapidly developing field and is
under recent intensive investigations owing to fundamental interests and numerous potential applications.
In this regard, the polarization properties of scattered light from plasmonic systems are of paramount
importance for gaining fundamental understanding on a number of interesting and intricate polarization
optical effects and for their potential applications. Coupling and inter-conversion between
the spin (SAM, circular / elliptical polarization) and orbital angular momentum (OAM, phase vortex)
degrees of freedom of light leading to the so-called spin orbit interaction (SOI) of light, is one such
intriguing spin (polarization) optical effect that has recently been observed in diverse plasmonic systems.
These have received particular attention because of their potential applications towards development
of novel spin-controlled nanophotonic devices.
Objective: Here, we briefly review the basic concepts of SOI, the resulting spin optical effects and
their manifestations in diverse nano-plasmonic systems.
Method: Mueller matrix spectroscopic system is developed and utilized for probing and tuning spindependent
Results: We provide illustrative results on controlled enhancement of the SOI effects in plasmonic
nanostructures. The specifics of a novel dark field Mueller matrix spectroscopic experimental system
and the representative results of studies using this system on the SOI and other spin-based plasmonics
effects are presented.
Conclusion: The implications of these results towards spin-controlled photonic applications are discussed.