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. 25, 1990
Filed:
Jul. 24, 1989
Motoyuki Yamamoto, Kawasaki, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A rib waveguide type semiconductor laser including p-type high impurity concentration layer formed between a p-upper cladding layer and p-ohmic layer and having an impurity concentration higher than the impurity concentration of the p-upper cladding layer and p-ohmic layer. The high impurity concentration layer acts to make small a discontinous portion of the valence band between the p-upper cladding layer and p-ohmic layer and change the steep junction to a smoothly inclined junction, thereby lowering the voltage drop across the junction.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile