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:
Jun. 29, 1999
Filed:
Feb. 21, 1997
Masahiro Ogusu, Tokyo, JP;
Shigeru Oshima, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Kanagawa-ken, JP;
Abstract
An optical multiplexing and demultiplexing device of a type using a lens and a diffraction grating, which incorporates a waveguide array having waveguide channels with narrow spacings for facilitating high resolution, where the narrow spacings are realized by forming an etching groove between each adjacent waveguide channels and providing a measure for preventing optical coupling among the waveguide channels in the form of an air gap, or a layer having a refractive index lower than a cladding layer, or a layer for absorbing/reflecting light, which is provided in the etching groove. The device also incorporates a reflection mirror for reflecting the initially diffracted lights from the diffraction grating back to the diffraction grating, such that the diffracting grating diffracts the diffracted lights reflected back from the reflection mirror again to produce wavelength division multiplexed/demultiplexed optical signals in high resolution.