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. 23, 2001
Filed:
May. 29, 1998
Toshiro Yoshida, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An analog optical transmission apparatus includes a semiconductor laser module, a bandpass filter, a distortion level detection circuit, a control signal generation circuit, and a distortion erasure circuit. The semiconductor laser module includes a semiconductor laser for converting a multi-carrier analog signal into an optical signal and outputting the optical signal and a light-receiving element for receiving the optical signal from the semiconductor laser and converting the optical signal into an electrical signal. The bandpass filter extracts only a specific distortion component from the electrical signal output from the light-receiving element. The distortion level detection circuit detects a level of the distortion component output from the bandpass filter. The control signal generation circuit generates a control signal corresponding to the distortion component level output from the distortion level detection circuit. The distortion erasure circuit generates a distortion signal having the same level and phase as those of a distortion from the semiconductor laser on the basis of the control signal from the control signal generation circuit and cancels the distortion from the semiconductor laser using the generated distortion signal.