9:30 AM - 11:30 AM
▲ [20a-PB6-2] Gold Nanoparticle Swarming Controlled by Particle Size and Wavelength of Trapping Laser
Keywords:Laser trapping, Gold nanoparticles, Light Scattering
Here we examine particle size and laser wavelength dependence of swarm formation by carrying out the laser trapping of Au NPs at glass/solution interface with Ti:Sapphire laser (continuous wave (CW) or femtosecond modes (fs), 800 nm in wavelength). We observe 200 nm and 150 nm Au NPs swarming perpendicular to laser polarization, while 100 nm Au NPs are trapped as a round assembly rather than the dumbbell like swarms. It is worth noting that this swarming of 150 nm Au NPs is observed with 800 nm CW laser but was not with 1064 nm CW laser. Scattering cross section at 800 nm wavelength for 150 nm Au NPs is larger than that at 1064 nm wavelength, which results in this difference.