Abstract: Hollow optical elements that derive optical power from compound-curved reflective surfaces to produce a desired composite optical power. The reflective surfaces in combination with polarization control, can produce a triple-pass arrangement that determines the optical power. Two functional films, one or both of which are formed (e.g., thermoformed), can be joined at the perimeter to form units that are mechanically robust and therefore preserve optical performance under mechanical load. The air-spaced cavity formed between the two layers is free of birefringence concerns, where polarization control is crucial to contrast. These optical elements can be installed in frames or headsets to form lightweight wearable magnifiers, wide-angle collimators, tele-photo lenses, or for any application requiring optical power.

Abstract: A compound retarder that creates independent control of Re and Rth. This can be done by forming a three-layer compound retarder, including a pair of matched ?A-plates, combined with single +A-plate. The +A-plate is typically an MD-stretched film, with retardation that is specific to the in-plane requirements (Re) of the application. The pair of ?A-plates have their optic axes crossed, such that Re=0, with an optic axis aligned parallel to the +A-plate. A single retardation value for the ?A-plate can produce improved field-of-view performance over a broad range of Revalues, making it a very practical means of universal compensation. While Rthis typically associated with a single retarder, retarder stacks with a diverse range of optic-axis orientations can be considered to have a compound (or composite) Rth value (RthC). The three-layer compound retarder has the practical benefit of enabling field-of-view compensation across a broad range of normal-incidence polarization transformations.

Abstract: Hollow optical elements that derive optical power from compound-curved reflective surfaces to produce a desired composite optical power. The reflective surfaces in combination with polarization control, can produce a triple-pass arrangement that determines the optical power. Two functional films, one or both of which are formed (e.g., thermoformed), can be joined at the perimeter to form units that are mechanically robust and therefore preserve optical performance under mechanical load. The air-spaced cavity formed between the two layers is free of birefringence concerns, where polarization control is crucial to contrast. These optical elements can be installed in frames or headsets to form lightweight wearable magnifiers, wide-angle collimators, tele-photo lenses, or for any application requiring optical power. They may be most appropriate for applications where light efficiency is not critical, such as well-lit environments, where the insertion-loss of 1 to 2 stops is not problematic.

Abstract: A liquid-crystal based color switch for use with an image sensor having sub-diffraction-limited (SDL) pixels. The color switch may switch between a first mode where green light is passed (and blue and red light is blocked) and a second mode where blue and red light is passed (and green light is blocked). The color switch may include an achromatic switch (such as a liquid crystal switch) and retarder stack filter that are both sandwiched between a first and a second polarizer. The SDL pixels may be distributed so that green subpixels are never adjacent to other green subpixels in the same row or column, so that red subpixels are always adjacent to green subpixels in the same row or column, and so that blue subpixels are always adjacent to green subpixels in the same row or column.

Abstract: Optical filters that enhance image quality by exploiting differences in the wavelength dependence of the spectral power distribution (SPD) and the degree of polarization between elements in a scene in order to preserve, and more preferably enhance, color-contrast between one or more salient objects in the scene and/or a salient object and a background. The higher degree of polarization may be associated with the background or the one or more salient objects. Color contrast is associated with one or more of a difference in saturation, a difference in hue, and a difference in lightness.

Abstract: Single-stage polarization interference filters (PIFs) which produce sinusoidal transmission spectra useful for (Red, Green, Blue) color enhancement (CE). The depth of the CE effect can be modulated by rotating a polarizer. Further, a color suppression (CS) (Cyan/Yellow) state is obtained by rotating a polarizer to the orthogonal state, and a spectrally flat neutral state is obtained at an intermediate polarizer orientation. Described are CE filters that are very stable in transmitted lumens and white-point during tuning, which can, for example, substantially eliminate the need for image post-processing. Tunable CE filters can be used for sensors, image capture, display, tunable light sources, augmented reality, virtual reality, and sunglass eyewear applications. Further described are camera filters with a unique two-step tuning mechanism, which allows photographers to make independent adjustments to functional filter characteristics using a single hand in a sequential manner.

Abstract: Used herein are two or more switchable variable birefringence liquid crystal devices, in combination with a passive retarder, to produce a device that switches between two retardation values. The device preserves the normal-incidence retardation in each of two voltage states over a broad range of incidence angles using a novel self-compensation scheme. According to one embodiment of this design, the retardation in the thickness direction remains zero in both the unenergized and fully energized states.

Abstract: An eyewear lens is described that provides polarization filtering and spectral filtering using polarization interference. The lens produces enhanced saturation and colorfulness, increasing enjoyment when observing commonly encountered imagery. The lens can be configured to optimize accuracy/efficiency when performing a task involving colored imagery, and can improve performance in sports. The lens can further be helpful for color discrimination by those with certain types of color vision deficiency.