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:
May. 23, 1989
Filed:
Nov. 01, 1988
Applicant:
Inventors:
Henricus C Krekels, Nijmegen, NL;
Pieter I Kuindersma, Eindhoven, NL;
Assignee:
U.S. Philips Corp., New York, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01S / ;
U.S. Cl.
CPC ...
372 49 ; 372 45 ; 372 46 ; 372 96 ; 372 99 ;
Abstract
A semiconductor laser of the distributed feedback (DFB or DBR) type is bounded in the longitudinal direction by end surfaces at right angles to the active region and at least one of these end faces is provided with an anti-reflection layer in order to suppress Fabry-Perot modes. In order to obtain an optimum effect, an anti-reflection layer of hafnium oxide is used. The invention is used with great advantage in lasers of the DCPBH (Double Channel Planar Buried Hetero-structure) type.