METHOD FOR HOLDING FINE PARTICLES BY LIGHT RADIATION PRESSURE AND DISPLACEMENT MEASURING METHOD - Nippon Telegraph and Telephone Corporation

Title:

METHOD FOR HOLDING FINE PARTICLES BY LIGHT RADIATION PRESSURE AND DISPLACEMENT MEASURING METHOD

Document Type and Number:

Japanese Patent JP3489646

Kind Code:

B2

Abstract:

PROBLEM TO BE SOLVED: To enable highly efficient trapping by changing the distance between lenses of a variable power lens group and a cone lens set and making the ring width and beam diameter of trapping laser beam variable.
SOLUTION: The beam from a beam source being Nd-YAG laser 1 is collimated with parallel laser beam 100 to be passed through an optical lens 2 to obtain trapping laser beam 101. This beam has a ring shape wherein the luminous intensity of a central part centering around an optical axis 5 is lower than that of a periphery and an object lens 3 condenses the beam into fine particles 4 desired to be trapped to hold fine particles 4. Herein, by changing the distance between lenses of the variable power lens group 21 (cone lens set 22) of the optical lens 2, the beam diameter (ring width) of the beam 101 is as it is and the ring width (beam diameter) can be changed. Therefore, ring-shaped laser beam having a ring diameter and ring width suitable for holding fine particles 4 at a place separated from a trapping object is obtained and highly efficient trapping is enabled.

Inventors:

Eiji Higurashi
Renji Sawada
Takahiro Ito
Hiroshi Nakata

Application Number:

JP12548896A

Publication Date:

January 26, 2004

Filing Date:

May 21, 1996

Export Citation:

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