为验证改进Friese光致旋转理论的合理性和可靠度,搭建了实时、快速测量单轴双折射样品粒子转动情况的光镊实验平台。捕获激光微束首先被聚光镜收集,经二向色镜和成像透镜后被四象限探测器接受,四象限探测器的信号变化反映了微观物体在囚禁光阱的运动情况,然后使用数据采集卡采集四象限探测器的信号,最后通过信号和图像处理分析得到样品粒子的运动情况,并把实验结果与理论分析对比。结果表明,改进Friese理论的模拟曲线与测得的实验数据更相符。该激光光镊系统可用于驱动微纳机械装置、测量微纳系统的力学参数以及组装生物器件等。
In order to verify the rationality and reliability of the theoretical model of modified Friese optical rotation, a real-time and rapid experimental platform of optical tweezers was set up to measure the rotation of uniaxial birefrin- genee particles. The laser microbeam was firstly collected by collecting lens, and then the beam was collected by four- quadrant detector(QD) across dichroic mirror and imaging lens. The signal of four-quadrant detector was collected with data acquisition card. Finally, rotation frequency of sample particles was measured through the analysis of signal and image data,moreover, the analysis and comparisons with theoretical curves were presented in detail. The results show that,the simulation curve of modified Friese model is much consistent with the experimental data. The optical tweezer can be applied to drive micro-nano mechanism, measure mechanical parameters of micro-nano system and assemble biological devices.