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. 02, 2004
Filed:
Apr. 25, 2002
Anish Goyal, Cambridge, MA (US);
George Turner, Westford, MA (US);
Massachusetts Institute of Technology, Cambridge, MA (US);
Abstract
A semiconductor laser operating in the mid-infrared region is described. In one particular embodiment, the semiconductor laser is provided having first and second cladding layers consisting essentially of GaSb that surround an active core, wherein the index of refraction of the first and second cladding layers is less than but close to the index of refraction of active core. The semiconductor laser in accordance with this invention has a low divergence angle with a high power efficiency. In an alternate embodiment, the semiconductor laser is provided having first and second cladding layers consisting essentially of Al Ga As Sb that surround the active core with an aluminum mole fraction between 0 and 25 percent. The index of refraction of the first and second cladding layers consisting essentially of Al Ga As Sb can be adjusted to match a variety of types of active cores and to provide a pre-determined divergence.