题 目:Some Theoretical Studies on Optical Micromanipulation and Their Realization
报告人:吴紫辉副研究员(Dr. Jack Ng,Department of Physics and Institute of Computational and Theoretical Studies,Hong Kong Baptist University)
时 间:7月17日(周三),下午3:00-5:00
地 点:物理馆512会议室
报告摘要:
As small particleswill migrate to the high laser intensity region to minimize the free energy,one can trap and manipulate small particles at will with a focused laser. This optical manipulation technique has applications range from the trapping and cooling of atoms, to large molecules, and to microscopic particles and biological objects.
I will briefly introduceour progresses on the theory and modeling of optical micromanipulation – the manipulation of micron-sized objects. I intend to cover all or some of the following topics,where, in addition to the theoretical predictions, their experimental implementation will also be briefly discussed.
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While it is anticipated that the scattering of light always pushes a particle forward, we demonstrate that the scattering force can sometimes pull a particle backward, in a manner similar to an "optical tractor beam" in scientific novel.
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A way to sort high-Qmicro-cavities with state-of-the-art accuracyis proposed. The bonding and anti-bonding forces associated with the hybridized whispering gallery modes of a pair of such micro-cavities are discussed.
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Huge resonant electromagnetic compressive or expansive pressures in metallic cavity were demonstrated.In infrared cavity, the large electronic kinetic energy is responsible for the compression, while in the microwave cavity the E-field leakage at the edge is responsible for the expansion.
Someexperimental and theoretical progress in optical binding (the use of light to bind particles into a single entity) will be reporte.