Method of interferometry with modulated optical path-length...

Details Method of interferometry with modulated optical path-length... Method of interferometry with modulated optical path-length...

2005-10-25

2005-10-25

Smith, Zandra V. (Department: 2877)

Optics: measuring and testing

By light interference

For dimensional measurement

C356S502000

Reexamination Certificate

active

06958817

ABSTRACT:
An interferometer has a source for generating a first beam and a second beam of a coherent monochromatic light having a wavelength λ, optical elements for directing the beams through two different optical paths having a path-length difference, a detector for detection of an interference signal of the beams, and a modulator for additionally varying the path-length difference periodically to allow the interference signal be detected near a path-length difference of λ/4 periodically. A maximum intensity change in the interference signal caused by a small period change of the path-length difference is thus detectable. The maximum intensity change caused by varying the path-length difference by at least λ/2 may also be detectable. The interferometer may be used to measure small vibrations, without pre-calibration and/or a feedback servo system for keeping the path-length difference near λ/4.

REFERENCES:
patent: 3772457 (1973-11-01), Macovski
patent: 4237399 (1980-12-01), Sakamoto
patent: 4289403 (1981-09-01), Allington
patent: 4554836 (1985-11-01), Rudd
patent: 4596466 (1986-06-01), Ulrich
patent: 4697926 (1987-10-01), Youngquist et al.
patent: 4762417 (1988-08-01), Wu et al.
patent: 5231325 (1993-07-01), Tamai et al.
patent: 5245408 (1993-09-01), Cohen
patent: 5394233 (1995-02-01), Wang
patent: 5481360 (1996-01-01), Fujita
patent: 5543914 (1996-08-01), Henshaw et al.
patent: 5623307 (1997-04-01), Kotidis et al.
patent: 5777742 (1998-07-01), Marron
patent: 5838439 (1998-11-01), Zang et al.
patent: 5883715 (1999-03-01), Steinlechner et al.
patent: 6020965 (2000-02-01), Endo
patent: 6115175 (2000-09-01), Maruyama et al.
patent: 6195168 (2001-02-01), De Lega et al.
patent: 6456380 (2002-09-01), Naganuma
patent: 6573996 (2003-06-01), Deliwala et al.
patent: 6583917 (2003-06-01), Melloni et al.
patent: 6616353 (2003-09-01), Helkey
patent: 6721094 (2004-04-01), Sinclair et al.
patent: 6778281 (2004-08-01), Ge
J.F. Li et al., “Simple, high-resolution interferometer for the measurement of frequency-dependent complex piezoelectric . . . ”, Rev. Sci. Instrum., 66 (1995), 215-21.
W.Y. Pan et al., “A sensitive double beam laser interferometer for studying high-frequency piezoelectric . . . ”, Rev. Sci. Instrum., 60 (1989), 2701-2705.

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