Numerical Confirmation of Multi-Reflections of Light Inside a Subwavelength Metal Slit Structure
1Department of Physics, Capital Normal University, Beijing 100048 2Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190 3Department of Physics, Tsinghua University, Beijing 100084 4Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006
Numerical Confirmation of Multi-Reflections of Light Inside a Subwavelength Metal Slit Structure
1Department of Physics, Capital Normal University, Beijing 100048 2Institute of Physics, Chinese Academy of Sciences, PO Box 603, Beijing 100190 3Department of Physics, Tsinghua University, Beijing 100084 4Laboratory of Photonic Information Technology, School for Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006
摘要The propagation behavior of light passing through a subwavelength metal slit structure is usually modeled by a Fabry-Perot (FP) resonant cavity based on the feature of transmission spectra. However, this mechanism belongs to a conjecture and it should be proven. We present a direct evidence from the numerical simulations of the amplitude distribution of the magnetic field by employing the time-domain simulation method. The light propagation behavior clearly shows a multi-reflection process inside a subwavelength slit as soon as it enters the slit. An analytical formula for calculating the field distribution involving the multi-reflection process is presented, and the theoretical calculations agree with the numerically simulated results. Our results provide explicit evidence that the FP model is reasonable to the description of the propagation process of light inside a subwavelength slit structure.
Abstract：The propagation behavior of light passing through a subwavelength metal slit structure is usually modeled by a Fabry-Perot (FP) resonant cavity based on the feature of transmission spectra. However, this mechanism belongs to a conjecture and it should be proven. We present a direct evidence from the numerical simulations of the amplitude distribution of the magnetic field by employing the time-domain simulation method. The light propagation behavior clearly shows a multi-reflection process inside a subwavelength slit as soon as it enters the slit. An analytical formula for calculating the field distribution involving the multi-reflection process is presented, and the theoretical calculations agree with the numerically simulated results. Our results provide explicit evidence that the FP model is reasonable to the description of the propagation process of light inside a subwavelength slit structure.
2010, Vol. 27 
