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. 14, 1998
Filed:
Jul. 13, 1996
Bryon Lynn Kasper, Allentown, PA (US);
Fridolin Ludwig Bosch, Bethlehem, PA (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A laser transmitter that includes a heating element coupled to the laser package and controlled to allow the laser to be kept at a higher temperature than ambient when low temperature extremes occur, thus limiting the range of wavelengths output by the laser over a given temperature range. The laser transmitter includes a semiconductor laser having an associated operating temperature; a laser driver circuit coupled to the semiconductor laser to control a modulation current and bias current conducted by the semiconductor laser; a heating element thermally coupled to the semiconductor laser; and a heating control circuit that (i) senses a temperature substantially representative of the ambient temperature surrounding the laser transmitter, (ii) energizes the heating element to provide heat to the semiconductor laser only when the temperature substantially representative of the ambient temperature is sensed below a predetermined minimum temperature, and (iii) upon energizing the heating element, controls heating of the heating element based on the temperature substantially representative of the ambient temperature.