Optics: measuring and testing – Photometers – Photoelectric
Patent
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.
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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.
Aoshima Shinichiro
Takahashi Hironori
Tsuchiya Yutaka
Hamamatsu Photonics K. K.
Pham Hoa
Rosenberger Richard A.
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