Development of microscopic and manipulating system in the optical near filed by evanescent photon force

本文针对存在于光界面边界处的倏逝光子力，对粒子和生物样品进行了观察和操作，得到了以下结果：作为光纤机械臂，设计了直径为10 μm的乳胶球在光纤端部的粘接方法。为了确定最佳的光学系统，利用时域有限差分法对机械手的出射光束进行了计算，并设计了机械手的结构，实现了对粒子的操纵和捕获。当波长为1.06 μm的YAG激光入射到光学机械臂上时，粒子可以在水中被捕获和操纵。特别是，我们清楚地表明，一个直径为40nm的金粒子是可以被捕获和操纵的，我们成功地安排了两个或更多的粒子。3 .将直径为100nm的金颗粒固定在光纤机械手所用球透镜的顶点处，成功地观察到倏逝光的散射现象。将两束相对的激光束以超过临界角的入射角入射到棱镜上，并对棱镜表面的粒子施加反方向的倏逝光子力。通过调整激光强度，我们成功地以每秒几十微米的速度定位了直径约为10 μm的粒子。作为一种非接触、非破坏的小物体定位新技术，利用倏逝光子力实现了直径为20 μm的乳胶球在二维平面上的位置可控。

This research was focused on evanescent photon force, which exists at border of optical interface, in order to observe and manipulate a particle and a biological sample, and following results were obtained.1. As an optical fiber manipulator, the method of gluing a latex ball with a diameter of 10 μm on optical fiber end was devised. In order to clarify an optimum optical system, an exiting beam pattern from the manipulator was calculated using electromagnetic field analysis by FDTD method, and the structure was designed in order to realize a manipulation and trapping of particle.2. When the YAG laser light (wavelength of 1.06 μm) was incident on the fabricated optical manipulator, and a particle was possible to trap and manipulate in water. Especially, it was shown clearly that a gold particle with a diameter of 40nm was able to be trapped and manipulated, and we succeeded in arranging two or more particles.3. The gold particle with a diameter of 100nm was made to fix at the apex of ball lens used in the optical fiber manipulator, and the scattering of an evanescent light was observed successfully.4. Two opposite laser beams were incident on the prism by the incidence angle beyond a critical angle, and the evanescent photon forces for reverse direction were given to the particle on the surface of a prism. We succeeded in positioning a particle with a diameter of about 10 μm at the speed of a few tens of micrometers per second by adjusting laser intensity.5. As a new technology of positioning for the small object with non-contacting and non-destruction manner, the method by evanescent photon force was developed and it was shown that the position of latex sphere of 20 μm in diameter was controllable in a two-dimensional plane.