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. 31, 1993
Filed:
Jan. 28, 1992
Steven H Macomber, Bethel, CT (US);
Jeffrey S Mott, Shenorock, NY (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
A chirped grating surface emitting distributed feedback semiconductor laser device (10) includes a P-side ohmic contact (28) and an N-side ohmic contact (36). A potential difference is applied across these contacts to create an electric field that induces a stimulated emission of coherent photon radiation. The coherent photon radiation produced by the stimulated emission process is incident upon a linearly varying, second order chirped grating surface (29). An output beam, directed normal to a chemically etched output window (38), is produced by a first order diffraction of photon radiation from the chirped grating surface (29). The output beam has a non-uniform longitudinal mode near-field output intensity profile and a non-abrupt longitudinal mode near-field phase, both due to a reduced destructive interference interaction in a second order diffraction of photon radiation along the grating surface (29). The output beam also has a desired single lobed longitudinal mode far-field output intensity profile. Moreover, the device achieves a 20% power efficiency due to the reduced destructive interference in the second order diffraction.