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:
May. 03, 1993
Filed:
Apr. 07, 1986
Robert J Spry, Tipp City, OH (US);
Abstract
A novel optical filter structure for selectively blocking radiation of predetermined wavelength is described which comprises a plurality of alternate first and second layers deposited on a substantially transparent substrate, the first layers comprising a transparent nontransitioning material of first refractive index, the second layers comprising a material characterized by a transition from ferroelectric phase having second refractive index to nonferroelectric phase having third refractive index different from the first and second indices upon being heated to a characteristic transition temperature, each of the first and second layers having a thickness substantially equal to one-fourth times the ratio of the predetermined wavelength to the respective index of refraction.