Multi-reflection process of extraordinary optical transmission in a single subwavelength metal slitYun-Song Zhou1, Ben-Yuan Gu2, Huai-Yu Wang3 and Sheng Lan4
1 Department of Physics, Capital Normal University - Beijing 100048, China
2 Institute of Physics, Chinese Academy of Sciences - P.O. Box 603, Beijing 100080, China
3 Department of Physics, Tsinghua University - Beijing 100084, China
4 Laboratory of Photonic Information Technology School for Information and Optoelectronic Science and Engineering - Guangzhou, Guangdong 510006, China
received 10 November 2008; accepted in final form 29 December 2008; published January 2009
published online 30 January 2009
The process of the light passing through a single subwavelength metal slit is analyzed by the finite-difference time-domain method. The simulation results show that the slit can be considered as an effective dielectric region sandwiched by two scattering regions at the two slit ends. Thus, the slit is analogous to a Fabry-Perot (FP) etalon consisting of a dielectric slab with high-reflection coatings on its two surfaces. A formula is presented to evaluate the phase shift caused by the amplitude transmissivity of the coatings.
42.79.Dj - Gratings.
78.66.Bz - Metals and metallic alloys.
42.25.Hz - Interference.
© EPLA 2009