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:
Jan. 03, 2023
Filed:
Mar. 06, 2020
Nec Corporation, Tokyo, JP;
Ken-ichiro Yoshino, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
An optical modulation method and device capable of stably generating an optical signal including a zero-intensity state among four states required for phase-time coding scheme by a nested modulator, is provided. A controller controls the phase difference generated by the phase shifter and an intensity and a magnitude of phase modulation provided by each of the first modulator and the second modulator to change an output lightwave of the nested modulator between four constellation points (S1-S4) on IQ plane. A first constellation point (S4) of the four constellation points has an intensity of 0, a second constellation point (S1) has a relative intensity of 1, each of a third constellation point (S2) and a fourth constellation point (S3) has a relative intensity ranging from 0 to 1, and the third and the fourth constellation points has a phase difference of 90 degrees.