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. 11, 2009
Filed:
Nov. 07, 2003
Susanna Maria Cattelan, Milan, IT;
Andrea Romano, Milan, IT;
Marco DE Donno, Milan, IT;
Aurelio Pianciola, Milan, IT;
Susanna Maria Cattelan, Milan, IT;
Andrea Romano, Milan, IT;
Marco De Donno, Milan, IT;
Aurelio Pianciola, Milan, IT;
PGT Photonics S.p.A., Milan, IT;
Telecom Italia S.p.A., Milan, IT;
Abstract
A method of controlling an external-cavity tuneable laser which has a wavelength-elective tuneable mirror, in which wavelength selectivity is achieved by an electrical signal provided by an alternating voltage. The tuneable mirror has a liquid crystal material, a diffraction grating and a planar waveguide optically interacting with the grating. The diffraction grating and the waveguide form a resonant structure that reflects only a selected resonance wavelength from among all the other wavelengths impinging thereon. Depending on the amplitude of the voltage applied to the tunable mirror, the tuneable mirror reflects radiation only at a given wavelength. The lasing output wavelength of the laser is selected to correspond to the resonance wavelength of the tuneable mirror. Accurate selection of the emission wavelength (frequency) of the tuneable laser by the tuneable mirror can be derived from the analysis of the signal modulation induced by the AC voltage applied to the tuneable mirror.