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:
Aug. 05, 1997
Filed:
Sep. 23, 1996
Masashige Ishizaka, Tokyo, JP;
Junichi Shimizu, Tokyo, JP;
NEC Corporation, , JP;
Abstract
A Mach-Zehnder modulator has a first waveguide path, a second waveguide path and first and second phase modulator sections respectively formed in the first and second waveguide paths. Those two waveguide paths have different equivalent refractive indexes so that with no modulation electric signal applied to the first and second phase modulator sections, lights waveguided through the first and second phase modulator sections have a phase difference of (2N+1).pi. (N: 0 or a positive integer). No voltage or a constant voltage is applied to the second phase modulator section, and a modulation signal is applied to the electrode of the first phase modulator section. When a voltage of 0 is applied to the first phase modulator section, a light OFF state is acquired, and when a voltage of V.pi. is applied to the first phase modulator section, a light ON state is acquired. Therefore, negative chirping is generated at the light ON time and the light OFF time.