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Heterodyne laser doppler probe and measurement system using the same

Foreign code F110004068
File No. N021-08WO
Posted date Jul 8, 2011
Country EPO
Application number 06715044
Gazette No. 1879015
Date of filing Mar 2, 2006
Gazette Date Jan 16, 2008
International application number JP2006303934
International publication number WO2006093209
Date of international filing Mar 2, 2006
Date of international publication Sep 8, 2006
Priority data
  • P2005-056754 (Mar 2, 2005) JP
  • 2006JP303934 (Mar 2, 2006) WO
Title Heterodyne laser doppler probe and measurement system using the same
Abstract There is provided a heterodyne laser Doppler probe capable of realizing the compatibility between its photoexcitation efficiency and speed measurement efficiency, and a measurement system using the same is also disclosed.The heterodyne laser Doppler probe introduces excitation light for photoexcitation from a first optical path (2) to an optical probe (1) and measurement light for heterodyne laser Doppler measurement from a second optical path (4) to the optical probe (1).After emission from the first optical path (2), the excitation light is introduced through a reflection mirror (3) and a beam splitter (6) into a focal lens (7), and then into a measurement object (excitation object) (8).On the other hand, the measurement light for heterodyne laser Doppler measurement is emitted from the second optical path (4) and passes through a 1/4 wavelength plate (5).Here, linearly polarized light is converted into circularly polarized light, and introduced through a beam splitter (5) and the focal lens (7) into the measurement object (excitation object) (8).The measurement light (signal light) reflected by the measurement object (excitation object) (8) passes through the same route to reach the 1/4 wavelength plate (5).By the 1/4 wavelength plate (5), the measurement light is converted from the circularly polarized light into the linearly polarized light, and the linearly polarized measurement light is returned through the second optical path (4) to the heterodyne laser Doppler measurement device.
Outline of related art and contending technology Background Art
The conventional type of optical probe having a photoexciting function and introducing light into the probe by an optical fiber, has transmitted excitation light and measurement light by the single optical fiber (refer to PATENT DOCUMENT 1).
[PATENT DOCUMENT 1] Japanese Unexamined Patent Application Publication No. 2003-114182
Scope of claims [claim1]
1. A heterodyne laser Doppler probe, comprising:
(a) a first optical path for guiding excitation light; and
(b) a second optical path for guiding measurement light,
(c) wherein the excitation light is emitted from the first optical path, and introduced into a focal lens in an optical probe to thereby be focused on a measurement object, and wherein the measurement light is introduced into the focal lens through a 1/4 wavelength plate in the optical probe to thereby be focused on the measurement object, and the measurement light reflected by the measurement object is returned to the second optical path through the focal lens and the 1/4 wavelength plate.
[claim2]
2. The heterodyne laser Doppler probe according to Claim 1,
wherein a reflection mirror and a beam splitter that receive the excitation light guided by the first optical path are arranged, and the measurement light that has been received by the 1/4 wavelength plate is received by the beam splitter; and
light emitted from the beam splitter is introduced into the focal lens, and the measurement light that has been returned to the focal lens is returned to the second optical path through the beam splitter and the 1/4 wavelength plate.
[claim3]
3. The heterodyne laser Doppler probe according to Claim 1,
wherein the first optical path is a first optical fiber, and the second optical path is a second optical fiber;
the excitation light from the first optical fiber is introduced through a first collimator lens into the focal lens, after having been emitted from the first optical fiber; and
the measurement light from the second optical fiber is introduced through a second collimator lens into the focal lens, after having been emitted from the second optical fiber.
[claim4]
4. The heterodyne laser Doppler probe according to Claim 1, 2 or 3,
wherein the measurement object is a cantilever; and the speed of the cantilever is measured.
[claim5]
5. The heterodyne laser Doppler probe according to any one of Claims 1 to 4, further comprising an adjustment mechanism capable of displacing the beam splitter, whereby a focal position of the excitation light on the measurement object is adjusted with respect to a focal position of the measurement light on the measurement object.
[claim6]
6. The heterodyne laser Doppler probe according to any one of Claims 1 to 4, further comprising an adjustment mechanism capable of displacing the reflection mirror, whereby a focal position of the excitation light on the measurement object is adjusted with respect to a focal position of the measurement light on the measurement object.
[claim7]
7. The heterodyne laser Doppler probe according to any one of Claims 1 to 4, further comprising an adjustment mechanism capable of displacing the beam splitter and the reflection mirror, whereby a focal position of the excitation light on the measurement object is adjusted with respect to a focal position of the measurement light on the measurement object.
[claim8]
8. A measurement system using the heterodyne laser Doppler probe according to any one of Claims 1 to 7, wherein the measurement light that has been emitted from the second optical path and reflected by the measurement object is reflected by the beamsplitter, to thereby introduce the measurement light reflected by the beam splitter into a measurement portion.
[claim9]
9. The measurement system using the heterodyne laser Doppler probe according to Claim 8, wherein by mirrors for optical path adjustment arranged in the first and second optical paths, the excitation light and the measurement light are introduced into the optical probe in a superimposed manner.
[claim10]
10. The measurement system using the heterodyne laser Doppler probe according to Claim 8 or 9, wherein a glass barrier is arranged in the first and second optical paths, whereby the light probe is allowed to be disposed in a vacuum, a gas, or a liquid, and a light source or an optical path adjustment mechanism is allowed to be disposed in the air.
  • Applicant
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
  • Inventor
  • KAWAKATSU, Hideki
IPC(International Patent Classification)
Specified countries Contracting States: CH DE LI
Reference ( R and D project ) CREST Nano Factory and Process Monitoring for Advanced Information Processing and Communication AREA
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