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. 08, 2009
Filed:
Sep. 20, 2006
Thomas Baur, Ault, CO (US);
Joel R. Blum, Northglenn, CO (US);
Paul A. Searcy, Longmont, CO (US);
Other;
Abstract
A birefringent optical filter and associated method are described which demonstrate improved performance for both fixed and tunable filter configurations. One exemplary embodiment involves an initial filter configuration, having an output polarizer, that exhibits an initial spectral filter response having an undesired transmission feature and a desired transmission feature. An additional polarizer follows the output polarizer and an adjustable retarder is disposed directly between the output polarizer and the additional polarizer to produce an overall spectral filter response that eliminates the undesired transmission feature, while passing the desired transmission feature. Another exemplary embodiment uses at least one reflective polarizer for passing light along the filter optical path, which light is characterized by a selected polarization, and for reflecting a rejected light that is characterized by a different polarization such that the rejected light is directed out of the optical path.