Title:
【発明の名称】二波混合法による散乱面からの過渡的運動の高感度、高速応答性光学的検出
Document Type and Number:
Japanese Patent JP3295432
Kind Code:
B2
Abstract:
A method and apparatus are provided of optically detecting transient motion from the surface of a workpiece. After directing a laser beam onto a surface of a workpiece the beam is reflected from it and then interferes with a pump beam removed from the laser source, inside a real-time holographic material, so as to form a grating diffracting the pump beam into a reference beam, which interferes at the output of the real-time holographic material with the received light beam, so as to produce a signal representative of the surface transient motion. An electric field is applied to the holographic material of sufficient magnitude to increase substantially the intensity of said reference beam and to give to this beam a phase differing substantially from the phase of said received light beam. The electric field is applied prior to the transient motion to be detected, for a time interval sufficiently long so as to capture the transient motion but sufficiently short a duration so as to avoid excessive heating of the real-time holographic material. The pump beam is of sufficiently high intensity so as to cause the response time of the real-time holographic material to be substantially shorter than a characteristic time defined as the time during which the phase of the received light, on average across its spatial distribution or locally, is not substantially changed.
Inventors:
Buruan, Alan
Derail, philip
Droje, Denny
Mont-Chalan, Jean-Pierre
Gerard
Derail, philip
Droje, Denny
Mont-Chalan, Jean-Pierre
Gerard
Application Number:
JP53661197A
Publication Date:
June 24, 2002
Filing Date:
April 09, 1997
Export Citation:
Assignee:
National Research Council of Canada
International Classes:
G01B9/02; G01B9/027; G01B11/16; G01B11/24; G01H9/00; G01N29/00; G01P3/36; (IPC1-7): G01B9/027; G01B11/16; G01H9/00
Domestic Patent References:
| JP4221721A | ||||
| JP694432A | ||||
| JP614903A | ||||
| JP1144090A |
Other References:
【文献】米国特許5680212(US,A)
Attorney, Agent or Firm:
Takashi Ishida (1 person outside)