Security documents often incorporate optically variable devices to prevent or hinder counterfeiters. Disclosed herein are layered optically variable devices such as color-shift foils, and methods for their production and use. Such devices afford new techniques for a user of a security document to check quickly and easily whether the security document is a legitimate document or a counterfeit copy.

Technologies are described for monitoring characteristics of layers of integrated computational elements (ICEs) during fabrication using an in-situ spectrometer operated in step-scan mode in combination with lock-in or time-gated detection. As part of the step-scan mode, a wavelength selecting element of the spectrometer is discretely scanned to provide spectrally different instances of probe-light, such that each of the spectrally different instances of the probe-light is provided for a finite time interval. Additionally, an instance of the probe-light interacted during the finite time interval with the ICE layers includes a modulation that is being detected by the lock-in or time-gated detection over the finite time interval.

Certain patternable reflective films are used as masks to make other patterned articles, and one or more initial masks can be used to pattern the patternable reflective films. An exemplary patternable reflective film has an absorption characteristic suitable to, upon exposure to a radiant beam, absorptively heat a portion of the film by an amount sufficient to change a first reflective characteristic to a different second reflective characteristic. The change from the first to the second reflective characteristic is attributable to a change in birefringence of one or more layers or materials of the patternable film. In a related article, a mask is attached to such a patternable reflective film. The mask may have opaque portions and light-transmissive portions. Further, the mask may have light-transmissive portions with structures such as focusing elements and/or prismatic elements.

Infrared reflectors are described. In particular, infrared reflectors with reduced off-axis color are described. Such infrared reflectors may be useful in laminated glass constructions, particularly for applications where the glass may be exposed to water.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The article includes the optical element (e.g., a single layer reflector, a single layer filter, a multilayer reflector or a multilayer filter) including one or more layers (e.g., a reflective layer(s), a constituent layer(s), and the like). The surface of the article can include the optical element with regions that impart different structural colors. The different structural colors imparted are due at least in part to the different structure (e.g., cross-sectional structure) of the optical element in certain regions.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color. The present disclosure provides for articles that exhibit structural colors through the use of an optical element having one or more layers. The optical element includes at least a first section and a second section. The first section imparts a first structural color and the second section imparts a second structural color. The first structural color and the second structural color differ from each other when viewed from the same angle of observation.

In various embodiments, the present invention is directed to contact lenses that utilize a multilayer coating of alternating high RI materials, such as melanin or polydopamine (PDA) and other low RI materials to create tunable iridescent colors and contain melanin or similar materials that impart photoprotection due to their broadband UV-vis absorption spectrum and ability to quench radicals.

The present invention is a film having at least one reflection band in which the reflectance is 30% or greater continuously in at least a 100-nm range in a wavelength range of 1200-1800 nm when light is incident from at least one side, the mean transmittance in a wavelength range of 430-600 nm is 70% or greater, and the average value of the axial rigidity of the film in the principal orientation axis direction of the film and in the direction orthogonal thereto is 45 N/m or less.

Infrared reflectors are described. In particular, infrared reflectors with reduced off-axis color are described. Such infrared reflectors may be useful in laminated glass constructions, particularly for applications where the glass may be exposed to water.

A multilayer optical film includes a plurality of polymeric layers arranged sequentially adjacent to each other. A difference in thickness between spaced apart first and second polymeric layers in the plurality of polymeric layers is less than about 10%. Each polymeric layer that is disposed between the first and second polymeric layers has a thickness less than about 400 nm. Each layer in a group of at least three polymeric layers in the plurality of polymeric layers that are disposed between the first and second polymeric layers has a thickness greater than an average thickness of the first and second polymeric layers by about 20% to about 500%. The group of at least three polymeric layers includes at least one pair of immediately adjacent polymeric layers.