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:
Nov. 26, 1996
Filed:
Nov. 23, 1994
Johannes A De Poorter, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
An optoelectronic semiconductor device (10) with a radiation-emitting semiconductor diode (3), preferably a diode laser (3), is particularly suitable as a radiation source in optical read and write systems such as bar code readers, laser printers, and optical disc systems. The diode (3) has one or two exit surfaces for radiation (R) which are provided with coatings (4). In such a device (10) it is found that a deposit rich in carbon is formed on the coating (4) of the laser (3), with the result that the output of the diode (3) fluctuates. The deposit may be avoided in that organic impurities are avoided or a selection is carried out in that respect. However, this is cumbersome and expensive. In a device (10) according to the invention is the diode (3) is present within an envelope (20) which is hermetically sealed off from the outer world (40), and a gaseous oxidizing compound (30) is present inside the envelope (20). It was surprisingly found that a gaseous oxidizing compound (30), preferably oxygen, counteracts or removes a deposit rich in carbon on the coating (4). Since the device (10) is hermetically sealed off from the outer world (40), degradation owing to water vapour or other aggressive gases is counteracted. The device (10) preferably contains dry and clean nitrogen to which at least approximately 0.2 vol. % oxygen (30) has been added. Particularly good results were obtained with a high-power laser (3) and a laser (3) which emits between approximately 0.6 and 0.9 .mu.m.