Apparatus for detecting the change of light intensity

Details Apparatus for detecting the change of light intensity Apparatus for detecting the change of light intensity

1990-11-26

1992-10-06

Rosenberger, Richard A.

Optics: measuring and testing

Photometers

Photoelectric

356222, 356368, 359255, G01J 142

Patent

active

051536676

ABSTRACT:
A light beam is chopped and split into two beams. Intensity of a first beam is changed by using, e.g., an electrooptic material in accordance of a change in a signal to be detected, such as a voltage in an electronic device, and detected by a first photodetector. On the other hand, a second beam is detected by a second photodetector without being subjected to the intensity change. At least one of the outputs of the first and second photodetectors are adjusted so that they become equal to each other when no signal is applied to the light intensity changing means. The difference of the thus adjusted output signals is detected by, e.g., a lock-in amplifier in a narrow band at the chopping frequency.

REFERENCES:
patent: 3675022 (1972-07-01), Nelson et al.
patent: 3994590 (1976-11-01), Di Martini et al.
patent: 4171909 (1979-10-01), Kramer et al.
patent: 4446425 (1984-05-01), Valdamanis et al.
patent: 4531092 (1985-07-01), Shibano
patent: 4632518 (1986-12-01), Jensen
patent: 4691106 (1987-09-01), Hyun et al.
patent: 4855591 (1989-08-01), Nakamura et al.
patent: 4890925 (1990-01-01), Kitamori et al.
A. Smith "Noise Reduction" Proc. IEEE, vol. 125, No. 10, Oct. 1978, p. 935--p. 941; FIG. 8.
EP-A-0021199 Shibaura Abstract, p. 4, line 8; p. 7, line 18; FIG. 1.
Janis A. Valdmanis et al., "Subpicosecond Electrooptic Sampling: Principles and Applications," IEEE Journal of Quantum Electronics, vol. QE-22, No. 1, Jan. 1986 pp. 69-78.

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