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:
Mar. 15, 2011
Filed:
Apr. 20, 2007
Akihiro Tanaka, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
Wakako Maeda, Tokyo, JP;
Akihiro Tanaka, Tokyo, JP;
Akio Tajima, Tokyo, JP;
Seigo Takahashi, Tokyo, JP;
Wakako Maeda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An optical communication apparatus that can perform stable intensity and phase modulation on an optical pulse at high speed is provided, as well as a quantum key distribution system using the apparatus. Using multilevel signals for the electric signals (RF, RF) to be applied to two arms of a two-electrode Mach-Zehnder modulator, phase modulation is performed on an optical pulse in accordance with the average of the levels of the signals (RF, RF), and intensity modulation is performed on the optical pulse in accordance with the voltage difference between the signals (RF, RF), whereby stable high-speed multilevel modulation can be realized. The cryptographic key generation rate in a decoy quantum key distribution system is enhanced.