Study of nonlinear optical properties of gold nanoparticles and PDOFT-Au

• Main Authors: Yi-yu Li, 李易諭
• Other Authors: Jaw-luen Tang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/39124002012576798066

碩士 === 國立中正大學 === 物理所 === 97 === In this work, we use the Z-scan technique with femtosecond and nanosecond laser pulses to investigate the nonlinear optical properties of the gold nano particles aqueous solutions (GNAS) and PDOFT-Au dissolved in toluene. Both solutions are selected because of their potentials in the applications of optical devices such as optical limiters and PLED. Gold nanoparticels of two different shapes are used in this study: (1) spheres with a radius ranging between 10 and 13 nanometer and (2) rods with a length of 80 nm and a cross section radius of 25 nm (an aspect ratio of 3.2). When the spheres show an absorption peak at 518 nm, the rods show an absorption peak at 700 nm, we suspect, according to the Kramers-Kronig relation, that they cause nonlinear refraction of opposite signs at wavelengths ranging between the wavelengths of these two absorption peaks. Therefore, we verify this suspect using 2.8 ns laser pulses at 532 nm. Toluene solution of PDOFT-Au has been used emission material in the PLED. Via this study, we wish to further understand its nonlinear optical properties.