红外显微观测被俘获吸光性颗粒

Infrared microscopic observation of trapped absorbing particles

光镊技术被广泛应用在俘获和操纵微纳米尺寸颗粒,目前被研究学者普遍接受的俘获吸光性颗粒的机理为光泳力.本文实现了对空气中被俘获的吸光性颗粒的红外显微观测.当激光器功率为1.0 W时,成功观测到被俘获墨粉颗粒(直径约7μm)和甲苯胺蓝颗粒(直径约为1—20μm)的温升约为14 K,为光泳力理论提供了强有力的证据.另外,首次用可见光显微镜和红外显微镜同时观测到被俘获颗粒的周期振荡现象,并分析了振荡现象的产生机理.

Optical tweezers technology is widely used to trap and manipulate particles, and the trapping mechanism generally accepted by researchers is due to the action of photophoretic force. In this paper, infrared microscopic observation of absorbing particles trapped in gaseous medium is first achieved. When the laser power is about 1.0 W, the temperature of trapped toner particles （diameter is about 7 μm） and toluidine blue particles （diameter is from 1 μm to 20 μm） rises by about 14 K, which provides strong evidence for the photophoretic force mechanism. In addition, the periodic oscillation of trapped particles is first observed by both optical microscope and infrared microscope, and the oscillation principle is analyzed.