Particle tracking stereomicroscopy in optical tweezers: Control of trap shape
Particle tracking stereomicroscopy in optical tweezers: Control of trap shape
复制标题
DOI：
10.1364/oe.18.011785
复制
发表时间：
2010-05-24
期刊：
影响因子：
3.8
通讯作者：
Padgett, Miles
中科院分区：
文献类型：
--
作者：
Bowman, Richard;Gibson, Graham;Padgett, Miles
我们提出了一种光学系统，能够产生立体图像来跟踪三维被捕获的粒子。每幅图像上的二维粒子跟踪产生三维位置信息。我们的方法允许使用高数值孔径(NA=1.3)的物镜和大的分离角，从而可以在340赫兹下以3 nm的分辨率轴向跟踪粒子。空间光调制器(SLM)是全息光钳中用于引导和分束激光的衍射元件，也能够进行更一般的操作。我们在这里使用一个通过改变显微镜物镜背面光圈的光束形状来改变横向和轴向陷阱刚度的比率。将光功率集中在后光圈两端的光束产生更有效的轴向俘获。使用SLM的灵活性允许我们创建不同形状的多个陷阱。(C)2010年美国光学学会
We present an optical system capable of generating stereoscopic images to track trapped particles in three dimensions. Two-dimensional particle tracking on each image yields three dimensional position information. Our approach allows the use of a high numerical aperture (NA = 1.3) objective and large separation angle, such that particles can be tracked axially with resolution of 3 nm at 340Hz. Spatial Light Modulators (SLMs), the diffractive elements used to steer and split laser beams in Holographic Optical Tweezers, are also capable of more general operations. We use one here to vary the ratio of lateral to axial trap stiffness by changing the shape of the beam at the back aperture of the microscope objective. Beams which concentrate their optical power at the extremes of the back aperture give rise to much more efficient axial trapping. The flexibility of using an SLM allows us to create multiple traps with different shapes. (C) 2010 Optical Society of America