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:
Dec. 22, 1992
Filed:
Jul. 02, 1991
Masayuki Kubota, Itami, JP;
Abstract
A variable wavelength light source using a semiconductor laser element suitable for use in optical communications is provided. Light emitted from one end surface of the semiconductor laser element is led along a path through a light wavefront converting element (e.g., a Fresnel lens) and a spatial light modulating element which are both formed in a waveguide layer, to a diffraction grating which is also formed in the waveguide layer. Light reflected from the diffraction grating is caused to travel back along the same path but in the opposite direction and to impinge on the semiconductor laser element. Wavelength selection of by the spatial light modulating element and the diffraction grating is utilized for generating and maintaining oscillation at a selected wavelength in the laser element. The wavelength of light is selected by selecting the wavelength of a surface acoustic wave generated the spatial light modulating element, i.e., by changing the frequency of a high frequency electrical signal applied to the modulating element.