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:
Aug. 13, 1996
Filed:
Jun. 27, 1994
Carolus J Van Der Poel, Eindhoven, NL;
Adriaan Valster, Eindhoven, NL;
Hubertus P Ambrosius, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Radiation-emitting semiconductor diodes are used as laser diodes or LEDs inter alia in optical disc systems, laser printers and bar code readers. The emission wavelength in these cases lies preferably in the visible range of the spectrum. Known diodes have an active layer (3A) and cladding layers (2, 4) which comprise either AlGaAs or InAlGaP. These known diodes have the disadvantage that they do not cover a portion of the visible spectrum between 880 and 600 nm. A diode according to the invention is characterized in that the active layer (3A) comprises Al.sub.x Ga.sub.l-x As and the cladding layers (2, 4) comprise Al.sub.y Ga.sub.w In.sub.l-y-w P, while the active layer (3A) has such an aluminjure content (x) and such a thickness (d) that the wavelength of the photoluminescence emission lies between approximately 770 and 690 nm. This results in the availability of (laser) diodes covering the entire spectrum from approximately 880 nm to 600 nm which operate satisfactorily, supply a high power, and are easy to manufacture. Preferably, the active layer comprises a (multiple) quantum well structure of alternating quantum well layers and barrier layers, both comprising AlGaAs, but with different aluminium contents.