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:
Jun. 11, 1991
Filed:
Sep. 15, 1989
Kurt Berthold, Munich, DE;
Anthony F Levi, Summit, NJ (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
The inventive quantum well opto-electronic devices of cavity length L.sub.C comprise, in addition to a 'gain' section, a 'loss' section that is optically coupled to the gain section but electrically substantially isolated therefrom. Through change of the electrical bias on the loss section the modal gain of the cavity can be changed. Devices according to the invention are useful in a variety of applications. Exemplarily, by making (in an inventive laser) L.sub.C /L.sub.A greater than about 20 (L.sub.A is the length of the loss section) and making the electrical isolation between the gain section and the loss section greater than about 3 k.OMEGA., fast amplitude modulation of the laser radiation is possibly. By applying appropriate AR coatings to the cavity of an inventive device, a fast variable-gain optical amplifier can be made. Finally, an inventive laser can be switched electrically between two widely spaced wavelengths, the wavelength difference being at least 10 nm. This makes possible use of inventive devices in apparatus such as information storage systems, information processing systems, and communication systems. Methods of operating such apparatus are also disclosed.