The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 1996
Filed:
Jun. 07, 1995
Akira Takeshima, Hamamatsu, JP;
Musubu Koishi, Hamamatsu, JP;
Hamamatsu Photonics K.K., Hamamatsu, JP;
Abstract
An optical frequency mixing apparatus is provided. Mixing of a frequency of an incident light intensity and a frequency (f.sub.3) of an AC signal generated by a signal generator, i.e., product calculation of the two signals is executed by a photoconductive photodetector of a photodetecting unit. This apparatus has a large allowance for unnecessary incident light such as background light and output characteristics having satisfactory linearity with respect to the incident light intensity, and can deeply set gain modulation. One of the frequency components of the sum and difference between the two signals, which is obtained as a result of product calculation, is selected and extracted using a frequency selector. As an incident optical signal, one optical signal whose light intensity has an AC component (frequency=f.sub.1) may be used. Alternatively, two optical signals whose light intensities have different frequencies (frequencies=f.sub.1 and f.sub.2) may be incident on substantially the same photodetecting area of the photoconductive photodetector.