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. 05, 2000
Filed:
Aug. 14, 1998
Junji Yoshida, Kanagawa, JP;
Noriyuki Yokouchi, Kanagawa, JP;
Takeharu Yamaguchi, Kanagawa, JP;
Kazuaki Nishikata, Tokyo, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Abstract
A waveguide-type variable-sensitivity semiconductor photodetector has a waveguide photodetector area and an optical attenuation area formed on an n-InP substrate. The optical attenuation area includes a GaInAs optical waveguide layer having a bandgap energy of 0.85 eV, a pair of upper and lower cladding layers each having a bandgap energy of 1.35 eV and an intermediate layer disposed at the heterojunction interface between the optical waveguide layer and the upper cladding layer and having a bandgap energy of 1.0 eV. A pile-up of halls at the heterojunction interface is prevented by the intermediate layer to improve the linearity of the output optical signal to the input optical signal.