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:
Mar. 08, 1988
Filed:
Dec. 16, 1985
Eugene I Gordon, Convent Station, NJ (US);
Lytel Incorporated, Somerville, NJ (US);
Abstract
A semiconductor laser diode comprising first and second parallel optically coupled waveguides is disclosed. The waveguides extend between first and second partially reflecting end facets. The first waveguide terminates at the first facet with a high reflection coating and at the second facet with an anti-reflection coating. The second waveguide terminates at the first facet with an anti-reflection coating and at the second facet with a high reflection coating. Thus, the feedback path for the laser involves portions of both waveguides and the coupling region therebetween. As a result, no standing waves are set up in either waveguide near the portions of the end facets which are anti-reflection coated and from which radiation is emitted so that processes which cause emitting facets to fail at high powers are mitigated. When the two waveguides are slightly different geometrically and are coupled by a periodic structure, laser oscillations are sustainable only in a narrow frequency band centered about a frequency which is relatively insensitive to changes in pumping current so that the laser may be directly modulated with a relatively small FM to AM ratio.