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. 01, 2013
Filed:
Aug. 24, 2007
Yasuaki Hashizume, Atsugi, JP;
Manabu Oguma, Atsugi, JP;
Takashi Saida, Atsugi, JP;
Masaki Kotoku, Atsugi, JP;
Takayuki Mizuno, Atsugi, JP;
Yasuaki Hashizume, Atsugi, JP;
Manabu Oguma, Atsugi, JP;
Takashi Saida, Atsugi, JP;
Masaki Kotoku, Atsugi, JP;
Takayuki Mizuno, Atsugi, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
A Mach-Zehnder interferometer circuit () is provided with two couplers () and two arm waveguides () connecting the couplers with each other, each fabricated on a substrate, in which a polarization rotation device () is disposed in a groove dividing each of the two arm waveguides into two, the polarization rotation device () for converting vertically polarized light into horizontally polarized light, and birefringence is adjusted by performing laser irradiation or the like partially into at least one of the two arm waveguides such that a difference between birefringence values divided by an optical wavelength to be used is within a range of 2 m-0.2 to 2 m+0.2 (m is an integer including zero), the birefringence values being those integrated linearly along the respective two arm waveguides in an optical signal travelling direction.