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. 07, 1990
Filed:
Jul. 30, 1985
Applicant:
Inventor:
Ikuo Mito, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
455609 ; 372 96 ; 455611 ; 455613 ; 455618 ;
Abstract
A bistable distributed feedback laser device is employed for transmitting optical signals. A bias current which is less than the threshold lasing turnoff current is supplied to the laser. A drive circuit provides a pulse current which, when added to the bias current, exceeds the threshold lasing turnon current. In this manner, the device is modulated so as to traverse the hysteresis region, hereby preventing undesirable expansion of the spectrum line width.