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:
Sep. 23, 2003
Filed:
Oct. 28, 1999
Matthew James Paschal, Rochester, MN (US);
Kevin Paul Demsky, Rochester, MN (US);
Ladd William Freitag, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Optical power adjustment is provided for parallel optical transmitters, in particular, for an array of vertical cavity surface emitting lasers (VCSEL's). The lasers in the array can be independently digitally adjusted with associated digital circuitry to compensate for manufacturing and temperature variations. In particular, the threshold current and modulation current for each VCSEL in the array, as well as a global temperature coefficient for all the VCSEL's in the array, can be digitally setup and adjusted for desired power levels. Once set, the associated digital code can be stored in non-volatile memory, and loaded at powering-up of the transmitters.