Photolytically and environmentally stable multilayer structure for high efficiency electromagnetic energy conversion and sustained secondary emission
AssigneePerformance Indicator, LLC
InventorsEdward D. Kingsley, M. Glenn Horner, Satish Agrawal, Louis Cincotta
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Abstract
A multilayer structure for authentication that includes an energy conversion layer, at least one stability enhancement layer and at least one optical variable element is disclosed. Also disclosed are methods of creating and using the inventive multilayer structure for authentication.
Claims48
A multilayer structure for authentication, said multilayer structure comprising:
- an energy conversion layer that converts energy of a primary electromagnetic radiation to a longer output wavelength, said energy conversion layer comprising:
- a polymer and a first photoluminescent material with a first radiation absorption spectrum that at least partially overlaps with the primary electromagnetic radiation;
- at least one stability enhancement layer that increases the photolytic and thermal stability of said multilayer structure;
- and
- at least one optical variable element that varies the longer output wavelength that is observed as a function of viewing angle.
The multilayer structure of 3, wherein said reflection layer comprises a plurality of alternate layers of non-metallic materials with high and low dielectric constants.
The multilayer structure of 3, wherein said reflection layer is a lenticular element or a microprismatic element.
A method of fabricating a multilayer structure for authentication, said method comprising:
- forming an energy conversion layer comprising a polymer and a first photoluminescent material with a first absorption spectrum that at least partially overlaps with a primary electromagnetic radiation;
- overlaying at least one stability enhancement layer over at least one side of said energy conversion layer that increases the photolytic and thermal stability of said multilayer structure;
- and
- applying at least one optical variable element into or onto at least a portion of at least one layer of said multilayer structure that varies a longer output wavelength that is observed as a function of viewing angle.
A method of identifying an object for authentication, said method comprising:
- applying a multilayer structure onto or into at least a portion of the object, the multilayer structure comprising:
- (i) an energy conversion layer that converts the energy of a primary electromagnetic radiation to a longer output wavelength, and
- (ii) at least one stability enhancement layer that increases the photolytic and thermal stability of said multilayer structure, and
- (iii) at least one optical variable element that varies the longer output wavelength that is observed as a function of viewing angle, and
- wherein said multilayer structure is exposed to the primary electromagnetic radiation and the longer output wavelength is detected.
Dependencies are inferred from the claim text.