Advanced methods for near field and femtosecond optical micromanipulation : Visiting Fellowship Application for Professor Min Gu

光可以像牵引光束一样在微观尺度上移动物质。这种方法之所以有效，是因为粒子和细胞之类的生物物体就像小透镜一样，可以弯曲光线，改变光线的方向。从牛顿定律我们可以看出，方向的改变是伴随着一个力的。这种力把粒子拉到光中最亮的区域。在本提案中，我们将研究使用短脉冲激光器的技术，该激光器提供非常短的高强度光爆发，而不是连续光束（cw）进行捕获。高能量爆发意味着我们可以进入我们通常无法进入的过程随着时间的推移，平均功率保持不变，所以我们可以像使用连续波光束一样移动物体。最后，我们研究了使用全内反射将颗粒全部放在大玻璃基板上的应用：就像你从游泳池底部向外看，但看到底部的反射一样。这种方法为我们提供了制作被困物体和细胞的大型二维阵列的机会

Light can move matter at the microsocpi scale rather like a tractor beam. This method works because particles and biological objects like cells act like small lenses that bend the light and change the direction the direction of flow. From Newton's law we can see that a change in direction is accompanied by a force. This force pulls particle to the brightest region of the light.In this proposal we will investigate technqiues that use short pulse lasers that give very short bursts of high intense light rather than a continuous beam (cw) of light for trapping. The high burst of energy means we can access processes that we normally could not yet the avearge power over time stays the same so we can move the objects as with a CW beam. Finally we investigate applications where the particles are held all on a large glass substrate using total internal reflection: rather like when you look out from the bottom of a swimming pool but see the reflection of the bottom. This method offers us the chance to make large 2D arrays of trapped objects and cells