Abstract: Optical gratings having a range of possible Bragg wavelengths can be produced using a single phase mask by exposing the mask to a non-collimated spatially filtered beam of light. A spatial filter removes high spatial frequency components from the beam, and a focusing system directs the filtered beam to a phase mask. A rate at which the beam is focused and a spacing between the phase mask and a photo-sensitive waveguide are varied to produce gratings in the waveguide having a range of possible periods.

Abstract: An optical film includes a reflective polarizing element and a particle-containing layer. The reflective polarizing element substantially reflects light having a first polarization state and substantially transmits a second polarization state. The particle-containing layer is disposed on the reflective polarizing element and in a same optical path as the reflective polarizing element. The particle-containing layer is configured and arranged to transmit light and includes a plurality of particles that roughen an exterior surface of the optical film. Preferably, using the optical film in an optical device does not substantially reduce the gain advantage of the optical device when compared with an optical device utilizing the same optical film without particles in the surface layer. Also described are optical devices using the optical film and methods of making and using the optical films.

Abstract: An anti-reflective composite is provided having very high visible light transmission and negligible visible reflectance over 400 nm-800 nm wavelengths. The composite of the invention includes (a) a light transmissive substrate; (b) a hard coat deposited onto the substrate; (c) a thin carbon layer having an average thickness between about 2 Å and about 100 Å; and (d) a plurality of transparent oxide layer pairs deposited onto the thin carbon layer, each transparent oxide layer pair comprising (i) a first transparent oxide having a refractive index between about 1.65 and about 2.65 and an average thickness between about 100 Å and about 3200 Å and (ii) a second transparent oxide layer having a refractive index between about 1.2 and about 1.85, and an average thickness between about 100 Å and about 3200 Å. The composite can also include an intermediate oxide layer disposed between the thin carbon layer and the first transparent oxide layer.

Abstract: The present invention introduces a novel scatter plate into the optical path of source light used for illuminating a replicated object. The scatter plate has been designed to interrupt a focused, incoming light beam by introducing between about 8 to 24 diffraction zones blazed onto the surface of the scatter plate which intercept the light and redirect it to a like number of different positions in the condenser entrance pupil each of which is determined by the relative orientation and the spatial frequency of the diffraction grating in each of the several zones. Light falling onto the scatter plate, therefore, generates a plurality of unphased sources of illumination as seen by the back half of the optical system. The system comprises a high brightness source, such as a laser, creating light which is taken up by a beam forming optic which focuses the incoming light into a condenser which in turn, focuses light into a field lens creating Köhler illumination image of the source in a camera entrance pupil.

Abstract: The privacy system apparatus and method of the present invention allow users of a publicly accessible terminal to privately access information displayed on a visual monitor of the terminal. In one embodiment, the privacy system 10 is implemented with a terminal 20 having a visual monitor 22 being disposed within a user area 50. The user area 50 provides a space for users 2 to privately access the terminal 20 and is at least partially separated from an external area 30 by a barrier assembly 40. A first filter 60 receives radiation 24 from the visual monitor 22 and transmits linearly polarized radiation 62 into the user area 50. A second filter 44 disposed between the user area 50 and the external area 30 transmits linearly polarized radiation 46. By selecting first and second filters, 60 and 44, respectively, with orthogonal transmission axes, radiation 24 emitted by the visual monitor 22 is substantially blocked from transmission to the external area 30.

Abstract: Device for elimination of the zero order beam emerging from holograms illuminated in polarized light includes a birefringent plate (5) illuminated by both said zero order beam (3) and by a diffracted beam (4) emerging from the hologram (2). The plate is arranged and sized such that one of the beams (3, 4) emerges from the plate with its plane of polarization not appreciably rotated and such that the other of said beams emerges with its plane of polarization rotated by 90°. The device further includes a polarizer (9) illuminated by the beams (3′, 4′) emergent from the birefringent plate (5), the polarizer having its plane of maximum transmittance parallel to the plane of polarization of the diffracted beam emerging from the birefringent plate as beam (4′). The device finds industrial applicability in the optical systems of video image projectors employing active matrix liquid crystal cells.

Abstract: An optical system with at least one optical element that causes a disturbance of the distribution of polarization over the cross section of a light beam wherein at least one birefringent optical element is provided, with a thickness which varies irregularly over the cross section, such that the disturbance of the distribution of polarization is at least partially compensated.

Abstract: A birefringent filter includes an input optical apparatus for receiving an input optical beam and producing therefrom parallel first and second optical beams offset in a first direction and having the same polarization. A birefringent filter unit receives the first and second polarized optical beams and produces a first and second elliptically polarized optical beams. An output optical apparatus combines predetermined components of the first and second elliptically polarized optical beams to form a first and second elliptical polarized output beams. The two output beams have intensities that vary inversely, in a periodic manner, as a function of frequency of the input optical beam.

Abstract: Methods for fabricating a color shifting multilayer interference film are provided. The interference film may be used to produce flakes for use in colorants having color shifting properties. The flakes can be interspersed into liquid media such as paints or inks which can subsequently be applied to objects or papers to achieve color variations upon shifts in angle of incident light or upon shifts in viewing angle. A five layer design of the interference film includes a first absorber layer, a first dielectric layer on the first absorber layer, a reflector layer on the first dielectric layer, a second dielectric layer on the reflector layer, and a second absorber layer on the second dielectric layer. The first and second dielectric layers are formed to have an optical thickness at a design wavelength that provides a color shift as the angle of incident light or viewing changes.

Abstract: Visual display monitors having a mirror providing a rear view are disclosed. The mirros include support structure to attach a reflective surface to the monitor such that the surface is rotatable while while maintaining a generally fixed orentation relative to the screen of the monitor. The mirror may include a case having front and rear portions rotatable relative to each other. The reflective surface may be rotatable within the front portion. Mirrors may be pivotally connected to monitors for some applications.

Abstract: A wire grid polarizing beam splitter has a generally parallel arrangement of thin, elongated elements which interact with electromagnetic waves of a source light beam to generally transmit or pass light of one polarization, and reflect light of the other polarization. The arrangement of elements has a throughput greater than approximately 50%, and an extinction greater than approximately 100. In addition, the arrangement of elements has a period less than approximately 0.21 &mgr;m, and a width to period ratio of between approximately 0.25 to 0.76. The elements have a thickness of between approximately 0.05 to 0.5 &mgr;m.

Abstract: A color shifting multilayer interference film is provided which may be used to produce flakes for use in colorants having color shifting properties. The flakes can be interspersed into liquid media such as paints or inks which can subsequently be applied to objects or papers to achieve color variations upon shifts in angle of incident light or upon shifts in viewing angle. A five layer design of the interference film includes a first absorber layer, a first dielectric layer on the first absorber layer, a reflector layer on the first dielectric layer, a second dielectric layer on the reflector layer, and a second absorber layer on the second dielectric layer. The first and second dielectric layers are formed to have an optical thickness at a design wavelength that provides a color shift as the angle of incident light or viewing changes.

Abstract: A method and apparatus for multicolor detection employing the natural chromatic aberration of a diffractive microlens to detect two or more colors or light. In the preferred embodiment the diffractive microlens detects two colors in the VLWIR spectral region and is focused on a two-part detector having a central region to detect the shorter bandwidth and a concentrically disposed region to detect the long band, VLWIR radiation. These detectors are arranged in a multicolor focal plane array to allow imaging.

Abstract: A color shifting multilayer interference film is provided which may be used to produce flakes for use in colorants having color shifting properties. The flakes can be interspersed into liquid media such as paints or inks which can subsequently be applied to objects or papers to achieve color variations upon shifts in angle of incident light or upon shifts in viewing angle. A five layer design of the interference film includes a first absorber layer, a first dielectric layer on the first absorber layer, a reflector layer on the first dielectric layer, a second dielectric layer on the reflector layer, and a second absorber layer on the second dielectric layer. A three layer design of the interference film includes first and second absorber layers with a dielectric layer therebetween. The dielectric layers are formed to have an optical thickness at a design wavelength that provides a color shift as the angle of incident light or viewing changes.

Abstract: A display case is provided having vertical members with internal conductors. The conductors are coupled to a source of low voltage electrical power such that adjacent vertical members are of differing electrical polarity. Shelf supports are designed to make electrical contact with the internal conductors when engaged in a vertical member. A light fixture, disposed on the underside of a shelf is electrically coupled to the shelf supports thereby completing an electrical circuit for energizing the light fixture.

Abstract: In a multistable optical logic element with a light-sensitive organic material (1) which undergoes a photocycle with several physical states by irradiation with light, and wherein a physical state is assigned a logical value which can be changed by addressing the element optically, the element initially before the addressing is in a metastable state generated in advance. A multistable optical logic element has been made proximity-addressable by providing at least a color light source (2) for optical addressing and at least one color-sensitive optical detector (5) adjacent to the light-sensitive material. In a method for preparing of the light-sensitive material (1) a desired initial metastable state is generated in the photocycle and assigned a determined logical value for the element.

Abstract: Disclosed are optical circulators possessing a longitudinal axis, the optical circulator including a first and second walk-off crystals optically coupled in a substantially equivalent optical distance, cascaded walk-off configuration, together with systems including such circulators, and methods of circulating optical signals.

Abstract: The invention relates to a phase annulus consisting of a phase shifting thin-film system, which, in the case of a cemented system, has the following structure: (first) substrate-Ag-nH-cement-(second) substrate, or a structure: (first) substrate-n1-Ag-n2-cement-(second) substrate. In the case of an uncemented structure, the thin-film system has the following structure: substrate-Ag-nH-air, wherein nH, n1 or n2 represent the respective refractive index of a dielectric film. Phase shifting of the positive phase contrast can be regulated in a targeted manner.

Abstract: Apparatus and methods for light activation of hardenable materials, such as filling materials located on dental surfaces, through fiber optic funnels coupled to light guides. Light generated by a light unit is directed through a light guide and then concentrated by a fiber optic funnel to direct concentrated light to hardenable materials. The fiber optic funnels comprises bundles of fiber optic strands. The fiber optic funnels are able to concentrate light according to their respective tapers. The fiber optic funnels are coupled to light guides by couplers which can be either rigid or elastomeric such that the couplers can be coupled with a specific light guide or conform to light guides having different diameters. A coupler can also enable a fiber optic funnel to pivot.

Abstract: An amplitude mask, and an apparatus and method for manufacturing a long period grating filter using the same, are provided. When a long period grating is manufactured by selectively passing laser light to an optical fiber, the amplitude mask periodically passes laser light to the optical fiber. The amplitude mask includes two masks having periodically alternating pass areas for passing the laser light and nonpass areas for preventing passing of the laser light, the two masks being continuously rotated in opposite directions. The period of the pass area thus continuously changes. In this mask, two masks each having a predetermined period are rotated in opposite directions, to thus provide an amplitude mask period depending on the angle of rotation. Thus, the period of the amplitude mask can be continuously changed.