Abstract: A method of manufacturing a three dimensional structure. In one embodiment, such structures comprise porous structures suitable for implantation in a host. Such a structure preferably exhibits geometric properties that tend to promote vascularization in the area of the structure when implanted into a host. The method includes selectively applying and exposing layers of biocompatible photoimageable material to create layers forming a cross-linked latticework structure having the desired geometric properties. Each layer is formed on top of a prior layer, preferably before any layer is developed. In one form, the structure is manufactured in connection with an implant device and promotes vascularization that supports bioacceptance/biocompatibility of the implant device.

Abstract: An apparatus and method for the production of ophthalmic lenses, and particularly contact lenses, which minimizes damage of the lens in removal from the mold. The ophthalmic lens is produced in a mold having a male part and a female part that are placed in proximate relation to each other to create a lens-forming cavity. At least the female surface of the female part mold is preferably coated with plasma and is irradiated for a predetermined time such that the female surface and/or surface coating is at least partially cured. Once the female surface, and alternately the male surface and other surfaces of the mold, is at least partially cured, a curable lens-forming material is placed into the lens-forming cavity and cured to form an ophthalmic lens.

Abstract: A high volume lens curing system is described. The high volume lens curing system is configured to cure multiple eyeglass lenses in a continuous manner.

Abstract: A lens forming apparatus for preparing a plastic eyeglass lens includes a first lens curing unit, a second lens curing unit and a conveyor system for moving mold assemblies between the two units. The apparatus may also include an anneal unit configured to apply heat to a substantially polymerized lens. The apparatus may be used to form an eyeglass lens from a lens forming composition that may include an aromatic containing polyether polyethylenic functional monomer, a photoinitiator, and a coinitiator. The lens forming composition may be cured by the application of activating light or activating light and heat.

Abstract: An apparatus for preparing a plastic eyeglass lens includes a coating unit and a lens curing unit. The apparatus is preferably configured to allow the operation of both the coating unit and the lens curing unit. The apparatus may also include a post-cure unit and a controller. The controller is configured to control the operation of the coating unit, the lens curing unit and the post-cure unit. The lens forming unit may include an LCD filter disposed between activating light sources and a mold assembly. The mold assembly preferably includes two mold members held together by a gasket. The gasket preferably includes four protrusions spaced at 90 degree intervals about the gasket. A lens forming composition may include a first photochromic compound, a second photochromic compound and a light effector. The light effector may alter the color of a lens when exposed to photochromic activating light, when compared to a lens formed from a lens forming composition which does not include a light effector.

Abstract: The invention relates to an apparatus for the photo-initiated chemical cross-linking of material (28). To form one or more mouldings the material is enclosed in an optically transparent mould (26). The apparatus has at least one light source (12), for example a pulsed UV light source by which the material (28) can be acted upon by a light that triggers the cross-linking. The region to be cross-linked in the mould (26) is determined at least partially by beam-delimiting elements (20, 22) between the light source (12) and the mould (26). That can be achieved by arranging between the light source (12) and the mould (26) a mask (20) having transparent and non-transparent surface portions. The mask (20) is then projected onto the material (28) that is enclosed in the mould (26) by projection optics (24). The projection of the mask (20) onto the material is effected in a telecentric beam path.

Abstract: The invention provides molds useful for the production of lenses with contoured edges. In particular, the molds permit production of a lens with an edge shaped to avoid its impingement on the lens wearer's conjuntival membrane.

Abstract: A method of manufacturing a solid state image pick up device, which is capable of increasing the hardness of a microlens is provided. A plurality of photosensing device arrays are formed on a semiconductor substrate. Next, a plurality of microlenses are formed on the semiconductor substrate on which the photosensing device arrays are formed. Next, the surfaces of the microlenses are hardened by irradiating light into the microlenses.

Abstract: A micro relief element which comprises

Abstract: A method for producing a tamper evident security holographic label and overlaminate using UV casting techniques, and a security device so produced, comprising a clear protective layer; a thin layer of clear UV cured resin cast partly onto the protective layer following a designed pattern; another layer of UV cured resin bearing a cast holographic image, wherein the bond of the holographic image layer is stronger toward the surface of the protective layer than it is toward the surface of the pattern layer; a reflective layer strongly attached to the adjacent holographic layer; and an adhesive layer bonded to the reflective layer. Such a composite product when adhered to a base substrate via the adhesive layer will show no visible security feature to the unaided eye due to the thin nature of the clear security pattern.

Abstract: A lens molding apparatus basically includes a lens molding tool in which a pair of lens forming molds for forming outer shapes of both surfaces of a molded lens are oppositely arranged on both sides of an annular forming frame in the thickness direction to form a target space therebetween, and a molding resin is injected in the target space to form an unhardened molded lens, wherein the unhardened molded lens is hardened by irradiating the unhardened molded lens with ultraviolet rays, to form a hardened molded lens. This lens molding apparatus is characterized in that optical characteristics of the unhardened molded lens are measured by a measuring system.

Abstract: A method and instrument to irradiate a light adjustable lens, for example, inside a human eye, with an appropriate amount of radiation in an appropriate intensity pattern by first measuring aberrations in the optical system containing the lens; aligning a source of the modifying radiation so as to impinge the radiation onto the lens in a pattern that will null the aberrations. The quantity of the impinging radiation is controlled by controlling the intensity and duration of the irradiation. The pattern is controlled and monitored while the lens is irradiated.

Abstract: A mold assembly for forming an ophthalmic lens, or a lens blank from which one ophthalmic lens is produced by effecting a cutting operation on at least one of a front surface and a back surface of the lens blank, the mold assembly consisting of a first mold having a molding surface and a second mold having a molding surface, which first and second molds are assembled together so as to define therebetween a mold cavity having a profile corresponding to that of the ophthalmic lens or the lens blank, the mold cavity being filled with a polymeric material which is polymerized to form the ophthalmic lens or the lens blank, wherein at least one of the first and second molds is a layered mold which is constituted by a composite sheet comprising a metal sheet layer and at least one resin layer which are laminated on each other, the at least one resin layer of the composite sheet providing the molding surface of the layered mold which partially defines the mold cavity.

Abstract: Described is a mold for producing optical lenses from a polymerizable material and a method for such production. Said mold comprises a gasket (1) enclosing an aperture (2), which aperture (2) extends along an axis (14), and providing a contact surface (3) radially extending from said aperture (2), a first molding shell (4) abutting against said contact surface (3), a second molding shell (5) arranged within said aperture (2) at a distance from said first molding shell (4), means (6) for pressing said first molding shell against said contact surface, means (7) for radially pressing said gasket against said second molding shell, and a filling opening, thereby forming a molding cavity (8) that can be filled with molding material between said first (4) and said second (5) molding shell and said gasket (1).

Abstract: An apparatus for preparing a plastic eyeglass lens includes a coating unit and a lens curing unit. The apparatus is preferably configured to allow the operation of both the coating unit and the lens curing unit. The apparatus may also include a post-cure unit and a controller. The controller is configured to control the operation of the coating unit, the lens curing unit and the post-cure unit. A lens forming composition may include an aromatic containing polyether polyethylenic functional monomer, a photoinitiator, and a coinitiator. The lens forming composition may be cured by the application of activating light or activating light and heat.

Abstract: The invention is directed to a method for making composite optical lenses, which includes the steps of obtaining an optical lens “core”; placing a semi-solid-like polymerizable composition in contact with at least one of the front or back surface of the core; compressing or heating the resulting semi-solid/core sandwich between two mold halves, where the mold contacting the semi-solid polymerizable material has a desired surface geometry; and exposing the semi-solid/core sandwich to a source of polymerizing energy. The resulting composite lens has the desirable characteristics of the core but is also easily fabricated with both toroidal curves and multi-focal pockets as a result of the semi-solid molding process.

Abstract: A method of cast molding an intraocular implant from two or more dissimilar materials using disposable molds. The subject cast molding method is particularly useful in the production of intraocular lenses manufactured from dissimilar materials. It is desirable to produce intraocular lenses from dissimilar materials in order to optimize the optical characteristics of the intraocular lens optic portion and to optimize stability and flexibility characteristics of the intraocular lens haptic elements.

Abstract: A process for preparing crosslinked polyvinyl alcohol contact lenses through hydrolysis of a copolymer of a vinyl ester with triallyl isocyanurate, which includes preparing a mixture of 100 parts by weight of the vinyl ester with 0.05 to 5 parts by weight of the triallyl isocyanurate, filling a mold composed of a male mold and a female mold with the mixture, applying ultraviolet ray to form a lens-shaped polymer, and hydrolyzing the resultant polymer. Since this process has a lens-shaped polymer formed without machinery processings, the lens surface is not roughened and the shape stability of the completed lens in a swollen state is so good that the handleability thereof is good and the lens can be mass-prepared with equalized quality.

Abstract: A method of cast molding an intraocular implant from two or more dissimilar materials using disposable molds. The subject cast molding method is particularly useful in the production of intraocular lenses manufactured from dissimilar materials. It is desirable to produce intraocular lenses from dissimilar materials in order to optimize the optical characteristics of the intraocular lens optic portion and to optimize stability and flexibility characteristics of the intraocular lens haptic elements.

Abstract: An apparatus and method for filling a mold for casting optical lens. Two molding shells and a closure member form a mold with a molding cavity. To fill the mold a fluid lens-forming material is introduced into the molding cavity through a casting opening formed in the closure member. Air is venting out during the filling process through a venting opening also formed in the closure member. Both the casting opening and the venting opening are located in the upper portion of the molding cavity but spaced apart from each other at an acute angle.

Abstract: An eyeglass lens forming composition containing light absorbing compounds which may undergo light initiated polymerization is provided. Typically, lens forming compositions that absorb light do not permit enough activating radiation to penetrate into the depths of the lens cavity to adequately initiate polymerization of the lens forming composition. An embodiment of the invention provides a system and method for curing such a lens forming composition to form a lens that does not transmit ultraviolet light. Activating light is used having a wavelength greater than the wavelengths of light which the light absorbing compounds absorb. The power of the formed lenses may be controlled by varying the lens forming conditions. Additionally, the lens forming process may be controlled using a microprocessor based control system.

Abstract: A method for fabricating a lenticular screen, wherein a platen is provided which has a flat surface and lenticular grooves machined into the flat surface. An optically curable material, such as a UV-curable polymer, is placed onto the platen sufficiently to fill the lenticular grooves. An optically transparent base substrate, such as glass, is then placed on top of the optically curable material. Finally, the optically curable material is irradiated through the substrate using a lamp.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.

Abstract: A method of forming a coating and an apparatus for forming a coating on an optical fiber capable of improving the work speed in recoating a coating forming portion of the optical fiber are provided. A coating removed part of a coated optical fiber, which is the portion where a coating of the optical fiber is formed, is set in a mold. A light-curing resin is provided on the coating removed part. Then, with the light-curing resin heated to the glass transition temperature thereof by a Peltier element, a heater and a temperature control unit, a light for curing is irradiates from a light source to cure the light-curing resin.

Abstract: A low-cost method of making unique and printable holographic papers and the like with the aid of radiation-curable coatings and flexible embossed or engraved flexible web film masters, and as a single, non-laminated sheet; and novel improved diffraction-refraction and holographic high-gloss surface papers, boards and the like, clear, metallized, pigmented or tinted.

Abstract: A one-piece intraocular lens formed from a copolymer of a hydrophilic monomer and an alkoxy-alkylmethacrylate. The intraocular lens is foldable so as to be insertable through a small incision in the eye.

Abstract: There is provided a photo-curable resin composition comprising a urethane-modified acrylic resin represented by structural formula (I) or (II) and a release agent as indispensable components: wherein five R1's each independently represent a hydrogen atom or a methyl group, R2 represents a C1-C16 hydrocarbon group, X and Y each represent a straight-chain or branched alkylene group, and, with the sum of l, m, n, and o being 100, l is an integer of 20 to 90, m is an integer of 0 to 50, n is an integer of 10 to 80, and o is an integer of 0 to 20; and wherein Z represents a group having a bulky cyclic structure, six R1's each independently represent a hydrogen atom or a methyl group, R2 represents a C1-C16 hydrocarbon group, X and Y each represent a straight-chain or branched alkylene group, and, with the sum of l, m, n, o, and p being 100, l is an integer of 20 to 90, m is an integer of 5 to 80, n is an integer of 0 to 50, o+p is an integer of 10 to 80, and p is

Abstract: A method and mold assembly to control the polymerization of a molded article. In one embodiment, radiation is delivered to the mold assembly in a controlled manner by fiber optics. In an alternate embodiment, a diffuser attached to a fiber optics bundle serves as a molding surface. This allows the polymerizable material between the diffuser and mold portion to be uniformly cured.

Abstract: A polymerizable composition comprising an effective amount of at least one tetrafunctional acrylate monomer. In one embodiment of the invention, a polymerizable composition is a compound comprising of at least 50 percent by weight of at least one tetrafunctional acrylate monomer, from 5 to 20 percent by weight of at least one modified bisphenol A epoxy diacrylate monomer, from 0 to 25 percent by weight of at least one acrylate monomer selected from aliphatic difunctional and polyfunctional acrylates, from 0 to 3 percent by weight of at least one UV absorber, and a source of free radicals. The lens-forming material resulted from the polymerizable composition is introduced to a lens mold with a mold cavity having a configuration conforming to the optical lens to be molded. A radiation energy source is used to cure the lens-forming material in the filled mold. The radiation energy source comprises a U-shaped UV light.

Abstract: A method and mold assembly to control the polymerization of a molded article. In one embodiment, an amorphous posterior mold comprising a non-critical surface having a controlled radius of curvature is used to produce molded articles. In an alternate embodiment, ophthalmic lenses are produced using a posterior mold in which the concave surface of the non-critical surface is filled with a liquid having a similar refractive index as the mold material. In still another embodiment, a positive lens is placed at a predetermined distance adjacent to the mold assembly to alter the irradiation path to the mold assembly. In still another embodiment, a positive lens is placed within the concave surface of the posterior lens.

Abstract: A method and mold assembly to control the polymerization of a cast optical device. The mold assembly includes at least one mold portion having a non-critical surface with fresnel or diffractive geometry. Alternately, a fresnel lens or diffractive lens may be placed at a predetermined distance from the mold.

Abstract: A mold assembly for forming an ophthalmic lens, the mold assembly comprising a first mold and a second mold which cooperate with each other to define therebetween a mold cavity having a profile following that of the ophthalmic lens, wherein the improvement comprises: at least one of the first and second molds being a coated mold consisting of a body portion including a backing surface having rigidity and mechanical strength enough to withstand a molding operation for forming the ophthalmic lens in the mold cavity, and a thermoplastic film retained on the body portion such that the thermoplastic film covers the backing surface of the body portion, the thermoplastic film having a molding surface which partially defines the mold cavity and which gives a corresponding one of opposite surfaces of the ophthalmic lens.

Abstract: A collectively coating die device (2) is provided for applying coating resin in a lump to coated optical fibers (1) arranged in parallel on one and the same plane so as to form a plurality of optical fiber ribbons (16) at the same time. The collectively coating die device (2) has a nipple portion (9) and a die portion (10), a resin accumulation space (8) formed between the nipple portion (9) and the die portion (10). The nipple portion (9) has two parallel planes and having a plurality of optical fiber passageways (13) shaped like ellipses in section and provided in the direction perpendicular to the planes. The die portion (10) has two parallel planes and has a plurality of optical fiber passageways (14) shaped like ellipses in section and is provided in the direction perpendicular to the planes. Each of the optical fiber passageways (13) of the nipple portion (9) has a tapered portion.

Abstract: A method of making a retroreflective article comprising on the top surface thereof a retroreflective sheet that comprises a monolayer of retroreflective elements wherein first portions of the monolayer are arranged in a contoured profile and second portions of the monolayer are arranged a substantially planar position.

Abstract: An optical-quality part such as an ophthalmic lens is provided having a PET polarizing film integrally bonded thereto and, optionally, a hard coating integrally bonded to either the PET polarizing film or to the optical construct containing the PET polarizing film. In a preferred construction, the lens material or film may be surface treated, either physically and/or chemically, for integrally bonding the film to the lens material. Similarly, in another preferred construction, the film may be physically and/or chemically surface treated for integrally bonding a hard coating to the PET film.

Abstract: A progressive lens mold, a method of making a progressive lens mold, and progressive lenses made using such mold or method. Back faces of progressive molds are preferentially tapered at their edges to reduce prism effects in lenses made using such molds. The tapering is accomplished by removing more of the back face adjacent the near portion vision zone of the mold versus the back face adjacent to the far vision zone of the molds.

Abstract: In an optical recording medium manufacturing method for forming an optical recording medium by hardening photo curing resin between a resin plate (11) and a template in order to provide a technique for manufacturing an optical recording medium that has excellent optical properties and that is not apt to undergo failure during production, the resin plate (11) is produced by a heating step (104) for heating thermoplastic resin (10) to a predetermined temperature to be melted, a feeding step (103, 105) for feeding the melted thermoplastic resin (10) into a mold (1), and a molding step (101, 102) for molding the thermoplastic resin (10), which has been fed into the mold (1), into the resin plate (11) by compression. Since molding is performed by the mold in a low-pressure and low-temperature environment, it is possible to prevent deterioration due to oxidation, and molding strains.

Abstract: The present invention provides a method for manufacturing an optical component that have increased transmittance in the ultraviolet region of the spectrum. The method includes the steps of cutting out a part from a block material; polishing optical sides of the part; subjecting the part to heat treatment at a temperature of between 100 and 900° C.; and subjecting the part to acid treatment.

Abstract: A simple method for producing a synthetic quartz glass having excellent homogeneity and high transmittance, which is useful as an optical material in producing steppers equipped with an ArF excimer laser as a radiation source. A method for producing a synthetic quartz glass for use in ArF excimer laser lithography, which comprises irradiating a highly homogeneous synthetic quartz glass containing less than 60 ppb of Na with ultraviolet radiation having a maximum wavelength of 260 nm for not less than the duration expressed by the equation: Y=(80X−1880)/Z wherein X represents an Na concentration (ppb), Y represents the duration of irradiation (hours), and Z represents the illuminance of an ultraviolet radiation on an irradiated surface (mW/cm2).

Abstract: A system and method cure a combination of a top and a bottom substrate with a resin disposed in-between. A cure platform includes a chuck on which the combination rests. A cure device cures the resin. An actuation assembly separates the chuck from the platform to thermally isolate the chuck during a curing operation performed by the cure device. A post cooling assembly may be provided to cool the chuck and the combination after a curing operation is performed by the cure device.

Abstract: The present invention relates to electrochromic polymeric solid films, manufacturing electrochromic devices using such solid films and processes for making such solid films and devices. The electrochromic polymeric solid films of the present invention exhibit beneficial properties and characteristics, especially when compared to known electrochromic media. The electrochromic polymeric solid films are transformed in situ from a low viscosity electrochromic monomer composition by exposure to electromagnetic radiation, and in so doing minimum shrinkage occurs. The electrochromic polymeric solid films of the present invention also perform well under prolonged coloration, outdoor weathering and all-climate exposure, and provide an inherent safety aspect not known to electrochromic media heretofore.

Abstract: The Application describes a method and devices for manufacturing a broadband cholesteric polarizer having a well-defined bandwidth and edge position. To this end, a liquid-crystalline cholesterically ordered layer comprising reactive chiral monomers and reactive nematogenic monomers having a different reactivity is polymerized by exposure to radiation. The invention is characterized in that the intensity of the radiation is increased substantially, preferably by a factor of 10 or more, when a desired edge position of the band is reached. As a result, the bandwidth and edge position of the reflection band reached at that moment are frozen as it were. A monochromatic sensor can be used to determine whether said edge position has been reached, the wavelength used by the sensor corresponding to the wavelength of the desired edge position of the band. Broadband, cholesteric polarizers having a well-defined bandwidth and edge position can very advantageously be used in a display.

Abstract: An apparatus for preparing a plastic eyeglass lens includes a coating unit and a lens curing unit. The apparatus is preferably configured to allow the operation of both the coating unit and the lens curing unit. The apparatus may also include a post-cure unit and a controller. The controller is configured to control the operation of the coating unit, the lens curing unit and the post-cure unit. The lens forming unit may include an LCD filter disposed between activating light sources and a mold assembly. The mold assembly preferably includes two mold members held together by a gasket. The gasket preferably includes four protrusions spaced at 90 degree intervals about the gasket. A lens forming composition may include a first photochromic compound, a second photochromic compound and a light effector. The light effector may alter the color of a lens when exposed to photochromic activating light, when compared to a lens formed from a lens forming composition which does not include a light effector.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.

Abstract: An apparatus and method for partially curing a polymerizable monomer or monomer mixture to form a soft contact lens includes a transport device for transporting a plurality of contact lens molds to a precure station in a low oxygen environment, each contact lens mold including a first and second mold half with a polymerizable monomer or monomer mixture therebetween. A clamping member having a plurality of mold engagement members clamps a first contact lens mold half against a second contact lens mold half for a predetermined pressure and time. While the mold halves of the contact lens mold are clamped, the polymerizable monomer or monomer mixture is exposed to a radiant energy source for polymerizing the polymerizable monomer or monomer mixture contained in each contact lens mold.

Abstract: In the method of manufacturing an optical recording medium according to the present invention, when an optical recording medium having at least first and second minute concave and convex surfaces formed thereon is manufactured, the first and second minute concave and convex surfaces are simultaneously molded on both surfaces of a substrate of the optical recording medium. Therefore, it is possible to manufacture a multilayer optical recording medium having an excellent symmetrical structure with respect to a vertical cross section direction of the substrate, i.e., in the thickness direction of the optical recording medium. Moreover, it is possible to effectively suppress the deformation thereof resulting from curing or shrinkage of an light curing resin or the like, absorption or removal of vapor in the air into or from a substrate, a transparent intermediate film or the like, and so on.

Abstract: System for making a plastic lens. Mold members are spaced apart to define a mold cavity. Ultraviolet light is directed against at least one of the mold members to cure a composition and form a substantially clear eyeglass lens in less than one hour.

Abstract: A light-curable polymer material for making an intraocular lens is a mixture of components consisting of oligourethanemethacrylate, octylmethacrylate, oligocarbonatemetharcrylate, 2,2-dimethoxy-2-phenylacetophenone and 2,4-ditretbutylortoquinone, wherein the aforesaid components are taken in the following weight % ratio: 2,2-dimethoxy-2-phenylacetophenone 0.1-0.7 2,4-ditretbutylortoquinone 0.001-0.006 octylmethacrylate  8-42 oligocarbonatemethacrylate 2-8 oligourethanemethacrylate balance. Also proposed are a method for making an elastic intraocular lens in which the aforesaid compounds are used as the initial components, and an elastic intraocular lens produced by this method.

Abstract: The invention concerns a method for the fabrication of an optical component with at least one fiber taper receptacle and a coupled fiber taper For this, a microstructure body is first made by coating a substrate with resist, the height of the resist diminishing essentially continuously across one region of the substrate. Next, the resist is exposed to synchrotron radiation through a mask and then developed. By electroforming and molding methods, such as micro injection molding, replicas of the microstructure body are created in plastic, for example. The invention further concerns an optical component, which has at least one fiber taper receptacle and one coupled fiber taper. The fiber taper receptacle is configured as a trough with essentially rectangular cross section. The trough height and width decrease essentially continuously across at least one region.

Abstract: A method of making a stamper for use in a data storage disk molding process. The method includes making a first stamper including the steps of providing a stamper body having an information layer thereon. The information layer is covered with a first metal layer. A second stamper is made from the first stamper, which includes the steps of covering the first metal layer with a second metal layer to form a stamper assembly, wherein the first metal layer and the second metal layer are bonded together. The first metal layer and the second metal layer are removed from the stamper assembly to form the second stamper, wherein removal of the first metal layer and the second metal layer is nondestructive to the information layer. In one application, the first metal layer and the second metal layer are made of nickel.