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:
Nov. 26, 1996
Filed:
Jun. 05, 1995
Toyoki Taguchi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A semiconductor laser apparatus comprises a semiconductor laser, a photodetector, first and second variable gain units, a controllable amplifying unit, a driving unit, and a compensation unit. A control signal is supplied to one of input terminals of each of the first and second variable gain units and an output signal of the photodetector is negative-fed back to the other of the input terminals of each of the first and second variable gain units. A varied gain of an error between the control signal and the output signal is output independently from each of the first and second variable gain units. The controllable amplifying unit amplifies the error signal from the first variable gain unit with desired frequency characteristics. The driving unit supplies a driving current to the semiconductor laser in accordance with a drive control signal from the controllable amplifying unit. The compensation unit negatively feeds back a compensation current to the negative feedback terminals to compensate a phase delay on the basis of the error signal output from the second variable gain unit.