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:
Jul. 16, 2019
Filed:
Sep. 15, 2016
Nec Corporation, Minato-ku, Tokyo, JP;
Tadashi Koga, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
In order to provide an optical modulator capable of controlling a bias voltage to correspond to transmission characteristics of a modulation means even when a multi-level modulation scheme is applied, an optical modulatoris provided with: an amplitude information control meansthat generates amplitude information for controlling the amplitude of an information signal to correspond to transmission characteristics of a modulation means, adds a dither signal to the amplitude information, and outputs the amplitude information; a bias value control meansthat generates and outputs a bias value for controlling the center of the amplitude of the information signal to correspond to the transmission characteristics of the modulation meansa data output meansthat corrects the amplitude of information data on the basis of the amplitude information, and outputs the information data as the information signal; the modulation meansthat corrects the center of the amplitude of the information signal on the basis of the bias value, modulates continuous wave light by using the information signal, and outputs a modulation signal; and an adjustment meansthat extracts, from the modulation signal, the dither signal added to the amplitude information, and adjusts the amplitude information and the bias value such that the differential value of the intensity of the dither signal added to the amplitude information becomes zero.