Based on the characteristics of evanescent wave moiré fringes generated from subwavelength gratings, we numerically investigated the contrast of moiré fringes for two gratings with and without a silver slab. The effect of the gratings’ geometrical parameters on the contrast of moiré fringes is analyzed in detail by using the finite-difference time domain method. Numerical results show that great enhancement of the contrast of evanescent wave moiré fringes could be achieved by surface plasmon excitations on a silver slab. These evanescent wave moiré fringes with high contrast will have potential applications in the nanofabrication field.
© 2008 Optical Society of America
Diffraction and Gratings
Original Manuscript: September 27, 2007
Manuscript Accepted: November 5, 2007
Published: February 29, 2008
Fabo Deng, Chunlei Du, and Xiangang Luo, "Characteristic analysis of evanescent wave moiré fringes," J. Opt. Soc. Am. B 25, 443-447 (2008)