Radiant energy – Photocells; circuits and apparatus – Optical or pre-photocell system
Patent
1993-03-09
1994-06-07
Nelms, David C.
Radiant energy
Photocells; circuits and apparatus
Optical or pre-photocell system
356365, G02F 101
Patent
active
053191943
ABSTRACT:
The birefringence of an object is measured by emitting first and second linearly polarized laser beams having optical frequencies f1 and f2 and transmitted in a same z-axis direction. The directions of polarization of the two laser beams are perpendicular to each other. After passing through the object, the laser beams are separated irrespective of the polarized directions thereof. A first analyzer transmits therethrough one of the laser beams that has been separated and polarized by about 45.degree. with respect to the x-axis. A second analyzer transmits therethrough the other of the laser beams separated and polarized in the x-direction or y-direction. Respective photodetectors are provided for detecting the outputs of the first and second analyzers. The birefringence amount of the object and the direction of a lag-phase axis or of an advanced-phase axis is detected based on the outputs of the photodetectors and a difference in the frequencies f1 and f2 of the first and second laser beams.
REFERENCES:
patent: 3902805 (1975-09-01), Redner
patent: 4179217 (1979-12-01), Robert et al.
patent: 4629323 (1986-12-01), Matsumoto
patent: 4749854 (1988-06-01), Martens
patent: 4970385 (1990-11-01), Tatsuno et al.
patent: 5102222 (1992-04-01), Berger et al.
Modine et al., "High frequency polarization modulation method for measuring birefringence", Applied Optics, vol. 14, No. 3, pp. 757-760, Mar. 1975.
Chudakov, "Investigation of Induced Birefringence with a Rotation Polarization Element, Pribory; Telchnika Elesperimenta", No. 1, pp. 210-212, Jan. 1977.
Caldwell, "Digital Lock-in technique for measurement of polarization of radiation," Optics Letters, vol. 1, No. 3, Sep. 1977, pp. 101-103.
Norito Suzuki et al., Applied Optics 11, pp. 35-38, issued on Sep. 15, 1984 (Partial English Translation).
Etsuhiro Mochida, "Measurement of Birefringence by Phase Modulating Method and Application Thereof", Optical Technology Contact vol. 27, No. 3 (1989), pp. 129-131 (Partial English Translation).
Kubo Keishi
Yoshizumi Keiichi
Matsushita Electric - Industrial Co., Ltd.
Nelms David C.
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