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:
Jan. 15, 1991
Filed:
May. 04, 1989
Kokusai Denshin Denwa Co., Ltd., Tokyo, JP;
Abstract
In measurement method of dispersion characteristics of an optical fiber, a laser for measurement connected to one end of the fiber and variable in output light wavelength and an oscillation for modulating a measurement light signal sent out from the laser are provided. The modulation frequency of the output from the oscillator is used as an reference electric signal. A measuring light signal obtained through the modulator 8 and transmitted through the fiber is converted into an measuring electric signal. And the characteristics is measured from the phase difference between the reference electric signal and the measuring electric signal, wherein an external modulator, an optical divider and a monitoring section are provided. The modulator modulates the measuring light signal sent out from the laser and having a narrow spectral linewidth. The divider divides the output light signal from the modulator, at a prescribed ratio. The measuring light signal obtained through the modulator is multiplexed with output light signal from a laser for monitoring by the section to generate a beat to measure the oscillation wavelength of the laser for measurement through optical heterodyne detection. And the characteristics is measured while the result of the measurement of the oscillation wavelength is compared with that of the measurement of the phase difference.