An optical film including a recording surface on which a plurality of unit blocks is disposed at regular intervals. For these unit blocks, phase components of light from a reconstruction point are calculated. The recording surface includes a calculated element region provided with an array of the unit blocks for which phase components of light from the reconstruction point are calculated for reproduction of an image. A first image is a monotone reconstruction image having even brightness, and a second image is a grayscale image having brightness gradation.

Embodiments herein describe a sub-micron 3D diffractive optics element and a method for forming the sub-micron 3D diffractive optics element. In a first embodiment, a method is provided for forming a sub-micron 3D diffractive optics element on a substrate without planarization. The method includes depositing a material stack to be patterned on a substrate, depositing and patterning a thick mask material on a portion of the material stack, etching the material stack down one level, trimming a side portion of the thick mask material, etching the material stack down one more level, repeating trim and etch steps above ‘n’ times, and stripping the thick mask material from the material stack.

There is provided a holographic optical element including: a hologram portion including a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and a colour filter portion formed on the hologram portion, the colour filter portion including a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion, whereby the plurality of groups of unit regions of the colour filter portion is spatially arranged to form a predetermined colour image. There is also provided a method of forming the holographic optical element. There is further provided an article having optical security incorporated therein.

Embodiments herein describe a sub-micron 3D diffractive optics element and a method for forming the sub-micron 3D diffractive optics element. In a first embodiment, a method is provided for forming a sub-micron 3D diffractive optics element on a film stack disposed on a substrate without planarization. The method includes forming a hardmask on a top surface of a film stack. Forming a mask material on a portion of the top surface and a portion of the hardmask. Etching the top surface. Trimming the mask. Etching the top surface again. Trimming the mask a second time. Etching the top surface yet again and then stripping the mask material.

The present invention discloses a method that combines two different hologram origination processes in a single photoresist layer by using an interlayer to transfer structures exposed by electron beam lithography into overlapped with dot-matrix hologram areas, and fabricated holographic structures are replicated in multilayer polymer films. Dot-matrix technique is low cost process, which has high origination speed and can be used for the patterning of large areas of holograms with high diffraction efficiency. Electron beam lithography allows the formation of high resolution structures. The proposed manufacturing method allows combining these two technologies so that the final security device could contain electron beam patterned high resolution diffraction gratings, computer generated holograms, as well as dot-matrix laser patterned large hologram areas with high diffraction efficiency, providing an increased level of protection.

The electronic card with printed circuit comprises at least one diffraction structure (DS) having a cavity (15) and a diffraction plate (17). In accordance with the invention, the diffraction structure is incorporated in the thickness of the electronic card with printed circuit, the cavity being formed, by removal of material, in the thickness of the electronic card with printed circuit and the diffraction plate being formed in a plate which is arranged on the electronic card with printed circuit and closes the cavity.

There is provided a holographic optical element including: a hologram portion including a plurality of groups of unit regions, each group of unit regions of the hologram portion being configured to produce a respective holographic image under a respective light illumination having a respective predetermined wavelength; and a colour filter portion formed on the hologram portion, the colour filter portion including a plurality of groups of unit regions, each group of unit regions of the colour filter portion being arranged on a corresponding group of the plurality of groups of unit regions of the hologram portion, whereby the plurality of groups of unit regions of the colour filter portion is spatially arranged to form a predetermined colour image. There is also provided a method of forming the holographic optical element. There is further provided an article having optical security incorporated therein.

The electronic card with printed circuit comprises at least one diffraction structure (DS) having a cavity (15) and a diffraction plate (17). In accordance with the invention, the diffraction structure is incorporated in the thickness of the electronic card with printed circuit, the cavity being formed, by removal of material, in the thickness of the electronic card with printed circuit and the diffraction plate being formed in a plate which is arranged on the electronic card with printed circuit and closes the cavity.

An optical film including a recording surface on which a plurality of unit blocks is disposed at regular intervals. For these unit blocks, phase components of light from a reconstruction point are calculated. The recording surface includes a calculated element region provided with an array of the unit blocks for which phase components of light from the reconstruction point are calculated for reproduction of an image. A first image is a monotone reconstruction image having even brightness, and a second image is a grayscale image having brightness gradation.

Embodiments herein describe a sub-micron 3D diffractive optics element and a method for forming the sub-micron 3D diffractive optics element. In a first embodiment, a method is provided for forming a sub-micron 3D diffractive optics element on a substrate without planarization. The method includes depositing a material stack to be patterned on a substrate, depositing and patterning a thick mask material on a portion of the material stack, etching the material stack down one level, trimming a side portion of the thick mask material, etching the material stack down one more level, repeating trim and etch steps above n times, and stripping the thick mask material from the material stack.