[18p-A201-1~11] 3.1 Basic optics and frontier of optics (merged with formerly 3.2 Equipment optics and materials)

▲ [18p-A201-8] Mid-Infrared Optical Sorting of Microparticles Composed of Si-O-Si Bonds

〇Yoshua Albert Darmawan¹, Takuma Goto¹, Taiki Yanagishima², Takao Fuji¹, Tetsuhiro Kudo¹ (1.Toyota Technological Inst., 2.Kyoto Univ.)

Keywords:mid-infrared, optical manipulation, ATR

We successfully manipulated microparticles based on their mid-infrared vibrational properties by employing a mid-infrared (mid-IR) quantum cascade laser (QCL) and an attenuated total reflection (ATR) setup. A 9.3 μm laser was chosen to excite the Si-O-Si bonds stretching. We employed an attenuated total reflection (ATR) setup to generate an evanescent wave on the prism surface and accelerate particles within its field. We used particles with various Si-O-Si bonds density measured by the conventional ATR-FTIR method to obtain the absorbance of microparticles at 9.3 μm. We obtained microparticles with different absorbances at 9.3 μm, depending on the molecular vibration mode and Si-O-Si bond density. It is shown that the velocity of accelerated microparticles is in agreement with the absorbance at 9.3 μm. Thus, this method provides a powerful method to manipulate microparticles with different molecular vibrational properties and densities.