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:
Aug. 20, 1996
Filed:
Oct. 05, 1993
Applicant:
Inventors:
Atsushi Takai, Kokubunji, JP;
Shoichi Hanatani, Yono, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
356218 ; 359110 ; 371-51 ;
Abstract
A method of testing a DC coupled optical receiver is provided. DC light is superimposed on an optical signal, the power of DC light is changed to observe waveform at a light extinction level, and the measurement and the prediction of the bit error rate are performed. Similarly, in a multi-channel DC coupled optical receiver, DC light is applied to a channel to be observed, while signal light is applied to other channels to observe cross-talk.