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:
Feb. 22, 1994
Filed:
Mar. 24, 1992
Naohiro Shimada, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An optical waveguide layer formed on a semiconductor substrate is etched to form two parallel grooves, thereby obtaining a low ridge having a relatively small height along the longitudinal direction of the grooves. Thereafter, a current blocking layer and a third cladding layer are formed. For this reason, the dimensions such as the height and width of the ridge can be controlled with high precision, and crystal growth for the current blocking layer can be relatively easily performed. Therefore, crystal defects are not concentrated near the ridge, and laser characteristic values fall within a sufficiently allowable range which cannot be obtained by the conventional laser device. A reliable laser device capable of obtaining desired laser characteristics with excellent uniformity and reproducibility can be obtained.