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:
Mar. 02, 2004
Filed:
Feb. 15, 2000
Masahiro Aoki, Kokubunji, JP;
Shinya Sasaki, Koganei, JP;
Tomonobu Tsuchiya, Hachioji, JP;
Hiroyuki Gomyo, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In order to form a wavelength tunable laser capable of tuning a wave over a wide range by simple control means, a thin film heater is mounted either over an upper electrode of a ridge waveguide semiconductor laser having ridge waveguides on a semiconductor substrate or over the semiconductor substrate and on both sides of the ridge waveguide with a gap of a few &mgr;m. By controlling a current passed to the thin film heater, the oscillation wavelength of the semiconductor laser is tuned. In the case where the thin film heater is mounted over an upper electrode of a ridge waveguide, a nonconductor is formed on both sides of the ridge conductor to more efficiently enable heat from the heater to reach an active layer of the ridge waveguide more efficiently.