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:
Sep. 17, 1991
Filed:
Jun. 19, 1990
Takao Naito, Kawasaki, JP;
Terumi Chikama, Machida, JP;
Shigeki Watanabe, Kawasaki, JP;
Tetsuya Kiyonaga, Kawasaki, JP;
Hiroshi Onaka, Kawasaki, JP;
Yoshihito Onoda, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A direct modulation PSK system and method, in a coherent optical fiber transmission system, in which an injection current supplied to a laser diode is adapted to be directly varied is disclosed. In this system or method, a modulating current pulse is superposed on a bias current for the laser diode so that a specified phase condition may be satisfied. Thereby, a differential coding circuit and an external modulator being indispensable for a DPSK system become unnecessary and, in addition, the system becomes less susceptible to the influence of wavelength dispersion than the DPSK system and able to reproduce the carrier.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile