School of Chemistry, University of Bristol, Cantocks Close, Bristol, BS8 1TS, UK.
Phys Chem Chem Phys. 2012 May 21;14(19):6741-8. doi: 10.1039/c2cp40371d. Epub 2012 Apr 4.
Bessel beams were used to create a counter-propagating optical trap for capturing and manipulating aerosol particles. Aerosol droplets were characterized through measurement of the elastic scattered light at three wavelengths; the trapping wavelength of 532 nm was used in conjunction with two probe beams at 405 nm and 633 nm to reduce the uncertainty in estimating droplet radii of 1 μm or less. Control of the aerosol size distribution sampled by the counter-propagating trap was demonstrated by varying the trapping beam core diameters and intensities. Smaller droplet sizes were preferentially selected with a 1.7 μm core diameter compared to cores of 2.7 μm and 4.5 μm. Further, an increase in core intensity was shown to broaden the range in droplet sizes that were optically trapped. The possibility of using such an approach to isolate and analyze the properties of single accumulation mode aerosol particles is discussed.
贝塞尔光束被用于创建反向传播的光学陷阱，以捕获和操纵气溶胶粒子。通过测量三个波长的弹性散射光来表征气溶胶液滴；532nm 的捕获波长与 405nm 和 633nm 的两个探测光束结合使用，以降低估计 1μm 或更小的液滴半径的不确定性。通过改变反向传播陷阱捕获的气溶胶尺寸分布的控制，可以证明控制的效果。与 2.7μm 和 4.5μm 的核心相比，具有 1.7μm 核心直径的较小液滴尺寸更优先地被选择。此外，核心强度的增加显示出可以扩大被光学捕获的液滴尺寸范围。讨论了使用这种方法来分离和分析单凝聚态气溶胶粒子的性质的可能性。
