| Popis: |
Optical forces, such as radiation pressure and the gradient force, are used to trap microscopic size dielectric particles. Regular arrays of optical traps can be constructed interferometrically, and more complex assemblages of traps could be made through holographic-type set-ups. Such optical-well arrays are useful in writing and erasing dynamic gratings. Two-dimensional `optical crystals', composed of monodispersed polystyrene spheres in water, display high diffraction efficiencies and low noise level, thanks respectively to a very high index modulation, and to the very small size dispersion of the scatterers. Many dielectric micro- objects can be arranged in such trap assemblies to form diffractive structures. This is the case in particular for biological materials such as bacteria or other organisms currently trapped with laser tweezers. The possibilities of manufacturing 3D diffractive structures are explored.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
