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:
Oct. 31, 1995
Filed:
Dec. 23, 1993
Lowell M Hobrock, Los Angeles, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
Abstract
An optical filter (18) includes a first layer (22) of material having a bandgap and being doped with an impurity having an energy level in the bandgap such that the first layer absorbs optical energy below a first wavelength and transmits optical energy thereabove. The filter further includes a second layer of optical material (26) disposed on said first layer (22) which transmits optical energy at a second wavelength, above the first wavelength, and reflects optical energy at a third wavelength above the second wavelength. The first and second layers in combination provide a filter (18) with high transmission in-band, low transmission out-of-band and a sharp cutoff therebetween.