Polarization property and optical simulation of metal grating

• Main Authors: Hsing-Jui Yu, 余星睿
• Other Authors: Chin-Bin Lin
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/14227433862851714731

碩士 === 淡江大學 === 機械與機電工程學系碩士班 === 103 === The main purpose of this paper is to simulate the sub-wavelength rectangle metal grating and trapezoid metal grating by optical software of Comsol. The simulation parameters comprise different metal materials (Cu, Ag, Ti and Al), grating period (120, 150, 200 and 250nm), metal thickness (50, 120, 200 and 250 nm), carbon thickness (100 and 120 nm), aluminum oxide thickness (0, 15, 20 and 25 nm), and incident angles (0, 15, 30 and 45 degrees). However, we can study the polarization properties of them by electric field and power flow distribution. According to the optical simulate result, aluminum which in the visible wavelengths could block the best effect of TE-polarized light transmittance. If increase the thickness of the metal, TM-polarized light transmittance will appear tends of red-shifted. To compare with rectangle metal grating and trapezoid metal grating, the TE polarized visible light transmittance of rectangle metal grating is higher than trapezoid metal grating about 30% and TM polarized visible light transmittance of rectangle metal grating is lower than trapezoid metal grating about 20%, respectively. By the incident angle increase to the 45 degree, the extinction ratio of the rectangle metal grating has been reduced by 80%. When increase the aluminum oxide thickness, the TE-polarized light transmittance will increase, but TM-polarized light transmittance will decrease.