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:
Apr. 02, 2002
Filed:
Feb. 09, 2000
Hans Peter Gauggel, Zurich, CH;
Karl Heinz Gulden, Zurich, CH;
Avalon Photonics Ltd., Zurich, CH;
Abstract
The present invention relates to a semiconductor laser device and a method for fabrication thereof, wherein the semiconductor laser device exhibits an improved mode selectivity. According to the present invention there is provided a semiconductor laser device having a first and a second reflecting region, the first reflecting region being composed of a Bragg mirror with alternating parallel layers having different refractive index, respectively, the first and second reflecting regions being adjacent to a laser active semiconductor region for emitting radiation of a predetermined wavelength and defining a longitudinal laser cavity; exciting device for exciting said laser active semiconductor region causing emission of radiation, wherein the first reflecting region further comprises a contact layer on top thereof, and one additional layer on top of the contact layer covering only a portion of the contact layer, wherein an arrangement of the alternating layers forming the Bragg mirror, an optical thickness of the contact layer, and a reflectivity and an absorption of the additional layer is selected so as to reduce reflectivity of the reflecting region in the portion of the contact layer covered by the additional layer, resulting in a smaller reflectivity compared to a portion of the contact layer, which is not covered by the additional layer. Moreover, a method is provided in order to fabricate the above mentioned semiconductor laser device, wherein a step of calculation is performed to predict an optimized optical thickness of the contact layer and an optimized composition and thickness of a metal layer to obtain a desired difference in reflectivity.