An apparatus for producing an optically variable film includes a laser configured to emit a beam, a telescoping lens section having a first lens and a second lens spaced apart by a first distance and an interferometer configured to direct the beam toward a workpiece. The laser may be operated at a predetermined power level and the first and second lenses are sized and spaced relative to one another to direct the beam onto the workpiece at about 200-230 dots per inch. The workpiece may include a polyethylene terephthalate (PET) layer configured to be ablated by the beam, forming a microstructure in the surface of the layer. The microstructure may be randomized and used to present non-chroma visual effects.

An apparatus for producing an optically variable film includes a laser configured to emit a beam, a telescoping lens section having a first lens and a second lens spaced apart by a first distance and an interferometer configured to direct the beam toward a workpiece. The laser may be operated at a predetermined power level and the first and second lenses are sized and spaced relative to one another to direct the beam onto the workpiece at about 200-230 dots per inch. The workpiece may include a polyethylene terephthalate (PET) layer configured to be ablated by the beam, forming a microstructure in the surface of the layer. The microstructure may be randomized and used to present non-chroma visual effects.

A laser ablation process can be configured to reduce the appearance of or eliminate a potentially objectionable diffraction effect that can occur when a workpiece or product that has been subjected to the ablation process interacts with light. The diffraction effect can be reduced by introducing irregularity into the arrangement of overlapping laser spots during the process. Other process parameters may be modified to reduce the diffraction effect, such as laser scan speed, laser pulse frequency, the position of the focal plane of the laser, the configuration of raster lines, or the energy profile of the laser beam, for example. The process modifications and configurations are particularly useful with products including an ablated surface that is intended to reflect light or to allow light to pass therethrough as part of its function.

An apparatus for producing an optically variable film includes a laser configured to emit a beam, a telescoping lens section having a first lens and a second lens spaced apart by a first distance and an interferometer configured to direct the beam toward a workpiece. The laser may be operated at a predetermined power level and the first and second lenses are sized and spaced relative to one another to direct the beam onto the workpiece at about 200-230 dots per inch. The workpiece may include a polyethylene terephthalate (PET) layer configured to be ablated by the beam, forming a microstructure in the surface of the layer. The microstructure may be randomized and used to present non-chroma visual effects.

The present disclosure discloses a method and apparatus for preparing a femtosecond optical filament interference direct writing volume grating/chirped volume grating. The method is characterized in that optical filaments are formed in glass by using femtosecond pulse laser, and plasma is controlled to quickly scan in the glass and etch a volume grating or chirped volume grating structure by adjusting the focal length of convex lens, laser energy and movement of motor machine. The apparatus includes a femtosecond pulse laser module, a pulse chirp management module, a pulse time domain shaping module, a laser separation and interference module, a glass volume grating processing platform module and a camera online imaging module.

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.

A laser ablation process can be configured to reduce the appearance of or eliminate a potentially objectionable diffraction effect that can occur when a workpiece or product that has been subjected to the ablation process interacts with light. The diffraction effect can be reduced by introducing irregularity into the arrangement of overlapping laser spots during the process. Other process parameters may be modified to reduce the diffraction effect, such as laser scan speed, laser pulse frequency, the position of the focal plane of the laser, the configuration of raster lines, or the energy profile of the laser beam, for example. The process modifications and configurations are particularly useful with products including an ablated surface that is intended to reflect light or to allow light to pass therethrough as part of its function.

The disclosure provides a method for fabricating a metallic optical metasurface having an array of hologram elements. The method includes forming a first copper layer protected with a conducting or dielectric barrier layer over a backplane structure by a damascene process. The first copper layer comprises a plurality of nano-gaps vertically extending from the backplane structure. The plurality of nano-gaps is filled with a dielectric material. The method also includes removing the dielectric material and a portion of the conducting or dielectric barrier layer to expose the portions in the nano-gaps of the first copper layer. The method may further include depositing a dielectric coating layer over the top portion and exposed side portions of the first copper layer to form a protected first copper layer, and filling the gaps with an electrically-tunable dielectric material that has an electrically-tunable refractive index.

A mirror and information image display assembly (300) for a vehicle, a holographic information image display system (300, 106, 104), a vehicle (100) comprising such an assembly, and a method of providing image information to an occupant of a vehicle are disclosed. The assembly has a reflective layer (302) and an image display means (304, 306), for displaying image information to an occupant of the vehicle. The image display means comprises a hologram (304), and a lighting means comprising a light source (306) for illuminating the hologram.

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.