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:
Apr. 06, 2010
Filed:
Jul. 21, 2005
Kazuhiro Nojima, Kanagawa, JP;
Tomoaki Ohira, Osaka, JP;
Kazuhiro Nojima, Kanagawa, JP;
Tomoaki Ohira, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An object of this invention is to provide a modulator, an optical transmitter and an optical transfer device which can modulate a channel signal while suppressing residual AM signals regardless of the frequency of a channel signal and suppressing deterioration of the channel signal due to impossibility of giving a sufficient FM demodulation amplitude. A modulatoraccording to this invention is a modulatorfor modulating an input signal, comprising: a branching circuitfor producing an inverted signal with an inverted phase of the phase of a first input signal transferred within a first frequency bandwidth; a first semiconductor laserfor FM-modulating the first input signal to produce a first FM-modulated light beam; a second semiconductor laserfor FM-modulating the inverted signal to produce a second FM-modulated light beam; an optical phase-modulating unitfor changing the phase of one of the first FM-modulated light beam and the second FM-modulated light beam on the basis of a second input signal transferred within a second frequency bandwidth, thereby producing a phase-modulated light beam; an optical merging unitfor merging the other of the first FM-modulated light beam and the second FM-modulated light beam and the phase-modulated light beam thereby to produce a modulated light beam; and a photoelectric converting unitfor converting the modulated light beam in a modulated signal through optical heterodyne detection.