Abstract: The invention relates to the combination of lower transmittance etalons with higher transmittance filters, including use of a single circular polarizer with high efficiency and optical performance for its filtered polarization, to achieve necessary throughput of a narrow bandpass region. The lower transmittance etalons can be achieved by using lower transmittance solid-state etalon materials, or by control of the coatings on the etalon. Alternate configurations are described that reduce the optical assembly's footprint, and/or include additional filters to remove stray light. An innovative option to heat the etalon directly is disclosed to actively stabilize and maintain the etalon's bandpass.

Abstract: A grating trim retarder fabricated from a form-birefringent multi-layer dielectric stack including at least one anti-reflection coating and supported on a transparent substrate is provided. The form-birefringent dielectric stack includes an axially-inhomogeneous element in the form of a ?C-plate grating and a transversely-inhomogeneous element in the form of an A-plate grating. Each of the ?C-plate and the A-plate gratings are fabricated with dimensions to form a zeroth order sub-wavelength grating structure. Fabricating the grating trim retarder with anti-reflection coatings and/or a segment where the ?C-plate and A-plate grating overlap enables the in-plane and out-of-plane retardances to be tailored independently according to the desired application.

Abstract: An automated verification system for authenticating an object having an optical security feature includes an optical system, a transport staging apparatus, and an analyzing device. The optical system includes one or more light sources that are capable of generating either narrowband or broadband light beams. The transport staging apparatus cooperates with the light sources and is configured to position the object such that one or more of the light beams strike a portion of the object where the security feature should be located. The analyzing device receives the light beams reflected or transmitted from the object and is adapted to analyze the optical characteristics of the light beams at varying angles and/or wavelengths to verify the authenticity of the object.

Abstract: A polarizing conversion system uses a polarizing beam splitter and reflector with a polarization conversion element to convert light from a lamp to a selected polarization state before providing the light to a light integrator, such as a light pipe or light tunnel. The light integrator provides homogenized polarized light to a light modulator. The polarization conversion system avoids increases efficiency compared to absorptive or simple reflective polarizers with fewer components than polarization conversion systems using patterned retarder plates and lenslet arrays. In one embodiment, the conversion elements are held to avoid adhesive or other bonds in the optical path. In other embodiments, high-temperature optical adhesive or optical contact bonding is used to assemble optical components for high-temperature operation. In a particular embodiment, a single-crystal quartz retarder plate is thermally matched to glass components in the polarization conversion system.

Abstract: The present invention is directed to methods and apparatus for enhancing the performance of visual display units which utilize plasma display panels. More specifically, the present invention provides methods and apparatus for providing an optically enhancing/noise suppressing device for positioning in front of the viewing surface of a plasma display panel. The device also increases the impact resistance of the PDP. The device of the present invention is manufactured separately from the PDP. The device may be provided with attachment means for securing the device to the surface of the visual display unit in a position in front of the viewing surface of the PDP or may be designed to be free-hanging, i.e., suspended, or otherwise positioned in front of the viewing surface of the PDP.