The present invention relates to the use of nanosystems as non deactivable security markers comprising metal atomic quantum clusters (AQCs) of at least two different size distributions encapsulated in a cavity with an inner diameter less than or equal to approximately 10 nm. These nanosystems are luminescence, particularly fluorescence after external excitation. The invention also relates to security documents, articles or elements incorporating these markers as well as to a method and a system for detecting the same.

An optical security component designed to be observed in a spectral observation band of between 380 nm and 780 nm by direct reflection, comprising an observation face and identifiable information, the component successively including, starting from the side opposite the observation face, a first support layer, identification elements obtained by printing an absorbent material in at least part of the visible spectrum, with a low refractive index, to reproduce at least part of the identifiable information, at least part of the identification elements being structured on one of their faces opposite the face across from the support layer, to form a first subwavelength grating, a second layer, with a high refractive index, covering the first support layer and the identification elements, and a third layer, with a low refractive index, transparent in the observation spectral band of the component.

An optical security component designed to be observed in a spectral observation band of between 380 nm and 780 nm by direct reflection, comprising an observation face and identifiable information, the component successively including, starting from the side opposite the observation face, a first support layer, identification elements obtained by printing an absorbent material in at least part of the visible spectrum, with a low refractive index, to reproduce at least part of the identifiable information, at least part of the identification elements being structured on one of their faces opposite the face across from the support layer, to form a first subwavelength grating, a second layer, with a high refractive index, covering the first support layer and the identification elements, and a third layer, with a low refractive index, transparent in the observation spectral band of the component.

A method of authenticating and/or identifying a security article including a first image includes superimposing at least partially the first image of the article with a second image. The second image may be produced by an electronic imager. The method further includes performing a relative movement between the first and second images so as to make it possible to observe an item of information relating to authentication and/or identification of the security article during the relative movement between the first and second images.

A method of authenticating and/or identifying a security article including a first image includes superimposing at least partially the first image of the article with a second image. The second image may be produced by an electronic imager. The method further includes performing a relative movement between the first and second images so as to make it possible to observe an item of information relating to authentication and/or identification of the security article during the relative movement between the first and second images.

An optical device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. In some examples, individual ones of the first and second segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the first and second segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

An optical device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. In some examples, individual ones of the first and second segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the first and second segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

A document, product, or package, such as a banknote, passport or the like comprises structures having dichroic effects that change color with viewing angle in both transmission and reflection. Such structures can be useful as security features that counter the ability to effectively use counterfeit documents, products, packages, etc.

A document, product, or package, such as a banknote, passport or the like comprises structures having dichroic effects that change color with viewing angle in both transmission and reflection. Such structures can be useful as security features that counter the ability to effectively use counterfeit documents, products, packages, etc.

A method of forming a security device includes selectively providing a high refractive index (HRI) layer to a first outwardly facing surface of a security device substrate, the HRI layer having a substantially transparent host material and particles having a dimension along at least one axis less than 200 nm, such that they are substantially non-scattering to visible light and the HRI layer is substantially transparent to visible light, and wherein; the particles have a refractive index of at least 1.8 and are present within the host material in a proportion such that the resultant refractive index of the HRI layer is at least 1.6. A corresponding security device, as well as security articles and security documents, are also disclosed.