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:
Sep. 17, 1996
Filed:
May. 15, 1995
Shigeru Nakamura, Tokyo, JP;
Kazuhito Tajima, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A semiconductor optical device having an optical waveguide which represents nonlinear refractive index change due to control light absorption. The waveguide has a bandgap wavelength that increases from its entrance to its exit. In the case of the waveguide divided into first to n-th regions, the bandgap wavelengths .lambda..sub.1, .lambda..sub.2, . . . , .lambda..sub.n-1, .lambda..sub.n of the regions satisfy the relationship .lambda..sub.1 <.lambda..sub.2 < . . . <.lambda..sub.n-1 <.lambda..sub.n. In the case of the waveguide not divided into regions, the bandgap wavelength .lambda. of the waveguide monotonously increases from the entrance to the exit. This device can operate by the control light having a lower energy than the conventional one.