Optical waveguides – Polarization without modulation
Patent
1997-03-11
1999-04-13
Lee, John D.
Optical waveguides
Polarization without modulation
25022727, 356351, 385 15, G02B 627
Patent
active
058945318
ABSTRACT:
A method and apparatus for detection of ultrasonic vibrations using an interferometer built, in its preferred embodiment, with optical fibers is disclosed. The method and apparatus are particularly useful where perturbations and disturbances adversely affecting other interferometer configurations are encountered. Light from a laser is split into two orthogonal polarization modes which travel through different fiber-optic paths and are directed to the object being investigated. A waveplate and a polarization splitter are used to re-direct the reflected light into the optical path opposite from which it arrived. A second polarization splitter combines the returning light and an interference signal is obtained with photodetectors. The bias phase-shift between the interfering beams is fixed with a second waveplate. The detected signal is the result of motion which modulates the phase of the light reflected by the object being inspected.
REFERENCES:
patent: 3630622 (1971-12-01), Delft et al.
patent: 4572949 (1986-02-01), Bowers et al.
patent: 4881817 (1989-11-01), Kim et al.
patent: 4966459 (1990-10-01), Monchalin
patent: 5120130 (1992-06-01), Bergh
patent: 5285257 (1994-02-01), Negishi et al.
patent: 5680212 (1997-10-01), Blouin et al.
"Nondestructive Evaluation with laser ultrasound," Mechanical Engineering, 1994, p. 63, vol. 116, (Oct.).
J.P. Monchalin, "Optical detection of ultrasound," IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Sep. 1986, p. 485, vol. UFFC-33, No. 5.
J.W. Wagner, "Breaking the sensitivity barrier: the challenge for laser-ultrasonics," IEEE Ultrasonics Symposium, 1992, p. 791,
M.J. Messerly, R.C. Mikkelson and J.R. Onstott, "A broadband single polarization optical fiber," Journal of Lightwave Technology, Jul. 1991, vol. 9, No. 7, p. 817.
J.V. Delden, "New 3-port/4-port optical circulator," Photonics Spectra, Jan. 1992, p. 81.
Karta Technology, Inc.
Lee John D.
Van Steenberg Gustav N.
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