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:
Oct. 13, 1987
Filed:
Dec. 04, 1985
Applicant:
Inventors:
Assignee:
NEC Corporation, Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01S / ; G02F / ;
U.S. Cl.
CPC ...
372 20 ; 372 26 ; 372 28 ; 455609 ;
Abstract
In an FSK laser transmitting apparatus, a light source can change the output light frequency. A driver performs FSK of the light source with a plurality of values. A beam splitter splits the output light from the light source into two split beams. A delay circuit delays one of the two split beams with respect to the other. A beam coupler combines delayed and nondelayed beams as the two split beams from the beam splitter. A controller detects the beat frequency of combined light from the beam coupler and supplies a control signal to the driver so as to set the beat frequency to be a predetermined value.