Theoretical analysis of obliquely excited surface plasmon self-interference.
We present the theoretical analysis of surface plasmon polaritons induced by a tightly focused light beam at oblique incidence. Firstly, we propose a geometrical model to explain the evolution of SPPs effect as light deviating from normal incidence, and introduce a concept of critical oblique angle (θ(co)) which is one of the key factors affecting the stability, efficiency and lateral resolution of SPPs. Secondly, the integral expressions for the transmitted SPP field excited by a linearly polarized vortex beam are derived, using angular spectrum representation and rotation matrix trans-formation, for the oblique directions as parallel and perpendicular to polarization plane. An interesting finding is that the system completely goes out of SPP self-interference resonance at an incident angle smaller than θ(co) at parallel obliquity, while larger than θ(co) at perpendicular obliquity.
Key Laboratory of Nondestructive Test (Ministry of Education), Nanchang Hangkong University, Nanchang, 330063, China. 18979106189@189.cn
Wendong
W
Zou
Pinbo
P
Huang
Wenjuan
W
Ma
Fei
F
Guo
D003198:Computer Simulation; D008027:Light; D008029:Lighting / Q000379:methods*; D008962:Models, Theoretical; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*