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. 22, 2005
Filed:
Nov. 22, 2002
Guido Chiaretti, Novate Milanese, IT;
Guido Chiaretti, Novate Milanese, IT;
STMicroelectronics, S.r.l., Agrate Brianza, IT;
Abstract
External cavity laser with reflector in optical wave guide, particularly HDBR laser, with an active element comprising a semiconductor optical amplifying cavity having a low-reflectivity facet (), for example a Semiconductor Optical Amplifier (SOA) with a facet () opposite to said low-reflectivity facet treated with a reflecting coating, or a Fabry-Perot laser, and an external reflector comprising a Bragg grating () formed in an optical wave guide () near a termination (), facing said facet, of a segment () of said optical wave guide coupled with the facet. The grating has a spatial profile of modulation of the refraction index such that a corresponding optical reflectivity spectrum (A) has an optical bandwidth (W) sufficiently small around a prescribed laser oscillation mode wavelength (γc) for the laser to oscillate only on the prescribed mode and not on other oscillation modes even in conditions of high-frequency direct modulation.