Abstract: A forensic feature for a secure document comprises a base document layer and a covert material applied to the base document layer. The covert material includes a carrier and forensic material within the carrier. The forensic material includes a ratio of salts or oxides of metals, such as rare earth metals. The ratio is selected to correspond with a source of the document. The forensic material may be mixed into a coating or ink that is applied at predetermined locations on a secure document. The ratio is then measurable from metal ion signals of the salts or oxides. This ratio, or some metric derived from it, may be linked with information embedded elsewhere in the document to enable verification of the document. Another forensic document feature has a forensic metric that is measurable from a covert material in the document, and this forensic metric corresponds to a source of the document.

Abstract: A forensic feature for a secure document comprises a base document layer and a covert material applied to the base document layer. The covert material includes a carrier and forensic material within the carrier. The forensic material includes a ratio of salts or oxides of metals, such as rare earth metals. The ratio is selected to correspond with a source of the document. The forensic material may be mixed into a coating or ink that is applied at predetermined locations on a secure document. The ratio is then measurable from metal ion signals of the salts or oxides. This ratio, or some metric derived from it, may be linked with information embedded elsewhere in the document to enable verification of the document. Another forensic document feature has a forensic metric that is measurable from a covert material in the document, and this forensic metric corresponds to a source of the document.

Abstract: A forensic feature for a secure document comprises a base document layer and a covert material applied to the base document layer. The covert material includes a carrier and forensic material within the carrier. The forensic material includes a ratio of salts or oxides of metals, such as rare earth metals. The ratio is selected to correspond with a source of the document. The forensic material may be mixed into a coating or ink that is applied at predetermined locations on a secure document. The ratio is then measurable from metal ion signals of the salts or oxides. This ratio, or some metric derived from it, may be linked with information embedded elsewhere in the document to enable verification of the document. Another forensic document feature has a forensic metric that is measurable from a covert material in the document, and this forensic metric corresponds to a source of the document.

Abstract: A Q-switched all-fiber laser utilizes a long period fiber grating (LPFG) modulator. The LPFG modulator is characterized by optical spectral characteristics that are controlled by application of stress via an actuator. In particular, the actuator applies stress to selected sections of the LPFG in order to modulate a light signal at a specified wavelength. Further, a controller is utilized to control the application of stress in the time domain, and thereby switch the Q-factor of the fiber laser cavity. In addition to the LPFG, the laser cavity comprises a pair of fiber Bragg gratings (FBGs) and a fiber gain medium.

Abstract: A Q-switched all-fiber laser has a long period fiber grating (LPFG) switch with optical spectral characteristics that are controlled by application of stress. An actuator applies stress to selected sections of the LPFG in order to switch a fiber laser cavity at a specified wavelength. A controller controls the application of stress in the time domain, thereby switching the Q-factor of the fiber laser cavity.

Abstract: A Q-switched all-fiber laser has a long period fiber grating (LPFG) switch with optical spectral characteristics that are controlled by application of stress. An actuator applies stress to selected sections of the LPFG in order to switch a fiber laser cavity at a specified wavelength. A controller controls the application of stress in the time domain, thereby switching the Q-factor of the fiber laser cavity.

Abstract: An image destruct material comprises a release layer positioned between an image receiving layer and a base layer. The adhesion between the release layer and the base layer is greater than adhesion between the release layer and the image receiving layer. The release layer material can be used in secure documents that have an image receiving layer. After information is printed on the image receiving layer, an overlaminate is applied over it. Removal of the overlaminate destroys the printed image on the receiving layer because of the relative adhesive properties of the image receiving layer, overlaminate and release layer.

Abstract: The invention provides hard coat and image receiving layer structures and related methods used in ID document production. These structures and methods provide ID documents that offer hard protection in areas where needed (e.g., in optical windows for machine readable data), and also provide image receiving layers for later printing of variable data, such as personalization information of the bearer. Implementations of the structure provide an effective interface between hard coat and image receiving layers that provides enhanced durability in manufacture and field use.

Abstract: A composition is provided for adhering a first article to a second article, the composition comprising a thermally active low Tg polymeric resin; and a multifunctional crystalline polymer. The thermally active low Tg polymeric resin can, for example, comprise 50-99% of the composition. The multifunctional crystalline polymer can, for example, comprise 1-50% of the composition. In one embodiment, the multifunctional crystalline polymer comprises 5-20% by weight of the composition. In one embodiment, the multifunctional crystalline polymer has a low molecular weight.

Abstract: An image destruct material comprises a release layer positioned between an image receiving layer and a base layer. The adhesion between the release layer and the base layer is greater than adhesion between the release layer and the image receiving layer. The release layer material can be used in secure documents that have an image receiving layer. After information is printed on the image receiving layer, an overlaminate is applied over it. Removal of the overlaminate destroys the printed image on the receiving layer because of the relative adhesive properties of the image receiving layer, overlaminate and release layer.

Abstract: An image destruct material comprises a release layer positioned between an image receiving layer and a base layer. The adhesion between the release layer and the base layer is greater than adhesion between the release layer and the image receiving layer. The release layer material can be used in secure documents that have an image receiving layer. After information is printed on the image receiving layer, an overlaminate is applied over it. Removal of the overlaminate destroys the printed image on the receiving layer because of the relative adhesive properties of the image receiving layer, overlaminate and release layer.

Abstract: The invention provides hard coat and image receiving layer structures and related methods used in ID document production. These structures and methods provide ID documents that offer hard protection in areas where needed (e.g., in optical windows for machine readable data), and also provide image receiving layers for later printing of variable data, such as personalization information of the bearer. Implementations of the structure provide an effective interface between hard coat and image receiving layers that provides enhanced durability in manufacture and field use.

Abstract: A composition is provided for adhering a first article to a second article, the composition comprising a thermally active low Tg polymeric resin; and a multifunctional crystalline polymer. The thermally active low Tg polymeric resin can, for example, comprise 50-99% of the composition. The multifunctional crystalline polymer can, for example, comprise 1-50% of the composition. In one embodiment, the multifunctional crystalline polymer comprises 5-20% by weight of the composition. In one embodiment, the multifunctional crystalline polymer has a low molecular weight.

Abstract: A security feature for an identification document and method for making it provide layers of security, including, for example, tamper evidence, optically variable effects, and personalized information that links the security information to the document and its bearer. The feature is made by printing a first material representing first information on a core layer of the document. This first material at least partially overlaps the core layer. One example is Xerographic printing of information about the ID document applicant and the applicant's photo. The process also applies a second material representing second information adjacent to the first material. One example is ink jet printing of personal information with a UV curable ink in the form of a relief pattern on the core layer. Finally, the process applies a laminate layer over the core layer. The laminate layer covers the first and second materials.

Abstract: An image destruct material comprises a release layer positioned between an image receiving layer and a base layer. The adhesion between the release layer and the base layer is greater than adhesion between the release layer and the image receiving layer. The release layer material can be used in secure documents that have an image receiving layer. After information is printed on the image receiving layer, an overlaminate is applied over it. Removal of the overlaminate destroys the printed image on the receiving layer because of the relative adhesive properties of the image receiving layer, overlaminate and release layer.

Abstract: The invention provides hard coat and image receiving layer structures and related methods used in ID document production. These structures and methods provide ID documents that offer hard protection in areas where needed (e.g., in optical windows for machine readable data), and also provide image receiving layers for later printing of variable data, such as personalization information of the bearer. Implementations of the structure provide an effective interface between hard coat and image receiving layers that provides enhanced durability in manufacture and field use.

Abstract: A tuning device for an optical fiber grating includes a multi-part confinement member. The confinement member includes a feature such as a channel in which the fiber grating is disposed. Movement of the different parts of the confinement member relative to one another causes compression or tension of the fiber grating. The confinement member may include first and second slides. One end of the fiber is bonded to the first slide, the other end of the fiber is bonded to the second slide. The grating section of the fiber is confined in a channel formed by adjacent surfaces of the slides. The dimensions of the channel are selected such that the fiber grating is maintained in a relatively straight orientation without buckling when compression strain is applied to the fiber. An actuator may be employed to control the strain applied to the fiber, i.e., to axially compress or stretch the fiber grating by driving one or both of the slides in a controlled manner.

Abstract: A composition is provided for adhering a first article to a second article, the composition comprising a thermally active low Tg polymeric resin; and a multifunctional crystalline polymer. The thermally active low Tg polymeric resin can, for example, comprise 50-99% of the composition. The multifunctional crystalline polymer can, for example, comprise 1-50% of the composition. In one embodiment, the multifunctional crystalline polymer comprises 5-20% by weight of the composition. In one embodiment, the multifunctional crystalline polymer has a low molecular weight.

Abstract: A Q-switched all-fiber laser utilizes a long period fibre grating (LPFG) modulator. The LPFG modulator is characterized by optical spectral characteristics that are controlled by application of stress via an actuator. In particular, the actuator applies stress to selected sections of the LPFG in order to modulate a light signal at a specified wavelength. Further, a controller is utilized to control the application of stress in the time domain, and thereby switch the Q-factor of the fiber laser cavity. In addition to the LPFG, the laser cavity comprises a pair of fiber Bragg gratings (FBGs) and a fiber gain medium.

Abstract: A tuning device for an optical fiber grating includes a multi-part confinement member. The confinement member includes a feature such as a channel in which the fiber grating is disposed. Movement of the different parts of the confinement member relative to one another causes compression or tension of the fiber grating. The confinement member may include first and second slides. One end of the fiber is bonded to the first slide, the other end of the fiber is bonded to the second slide. The grating section of the fiber is confined in a channel formed by adjacent surfaces of the slides. The dimensions of the channel are selected such that the fiber grating is maintained in a relatively straight orientation without buckling when compression strain is applied to the fiber. An actuator may be employed to control the strain applied to the fiber, i.e., to axially compress or stretch the fiber grating by driving one or both of the slides in a controlled manner.