Abstract: Ultra Violet (UV) light produced by a light source is converted to visible light and utilized in a visible light output of the light source. The light source is, for example, a light source in an illuminator of a projection device. UV light that is typically filtered out of the illuminator is converted by a UV absorbing visible light radiating phosphor. The UV light is directed to the phosphor by, for example, reflecting the UV light out of a light path, concentrating the UV light via a concave reflector, and directing the UV light to the phosphor. The re-radiated visible light is then injected back into the light path of the light source. In one embodiment, the re-radiated visible light is injected into a “shadow” of the light path.

Abstract: An absorptive layer is added to an image display system. The absorptive layer is selected to compensate for tint in a black state of a displayed image. In a Liquid Crystal On Silicon (LCOS) based light engine, blue wavelengths may cause a predominate tint in black portions of an image (or an entirely black image is tinted blue), and the absorptive layer is calculated to absorb an amount of blue equivalent to the tint. The absorptive layer is, for example, an unbalanced magenta dichroic, or a yellow filter. The yellow filter may be placed at any point in the light chain, including input/output of a kernel, input/output of a projection lens, or portions of a light engine or display screen. An unbalanced magenta may be constructed by adding a yellow filter to an existing magenta dichroic in the kernel design.

Abstract: Ultra Violet (UV) light produced by a light source is converted to visible light and utilized in a visible light output of the light source. The light source is, for example, a light source in an illuminator of a projection device. UV light that is typically filtered out of the illuminator is converted by a UV absorbing visible light radiating phosphor. The UV light is directed to the phosphor by, for example, reflecting the UV light out of a light path, concentrating the UV light via a concave reflector, and directing the UV light to the phosphor. The re-radiated visible light is then injected back into the light path of the light source. In one embodiment, the re-radiated visible light is injected into a “shadow” of the light path.

Abstract: An absorptive layer is added to an image display system. The absorptive layer is selected to compensate for tint in a black state of a displayed image. In a Liquid Crystal On Silicon (LCOS) based light engine, blue wavelengths may cause a predominate tint in black portions of an image (or an entirely black image is tinted blue), and the absorptive layer is calculated to absorb an amount of blue equivalent to the tint. The absorptive layer is, for example, an unbalanced magenta dichroic, or a yellow filter. The yellow filter may be placed at any point in the light chain, including input/output of a kernel, input/output of a projection lens, or portions of a light engine or display screen. An unbalanced magenta may be constructed by adding a yellow filter to an existing magenta dichroic in the kernel design.

Abstract: A phosphor layer is positioned to absorb UV light and re-radiate usable light in other wavelengths. The UV light is reflected to the phosphor by a thin film placed in a light path. The phosphor re-radiates the usable light in a direction of the light path. Curved mirrors or directive reflectors are utilized to direct some of the re-radiated light toward the light path. In one embodiment, usable light in the light path is reflected by a thin film, UV light is passed by the thin film toward the phosphor, and the re-radiated light is directed toward the reflected visible light path.

Abstract: The present invention relates to a ruggedized optical fiber collimator. An embodiment of the present invention includes a housing, an optical fiber, a collimating lens system comprising at least one lens, and an inner tube. The optical fiber extends into the housing through the inner tube. The housing houses the inner tube and the collimating lens system. The optical fiber terminates in the housing. The housing, the optical fiber, the collimating lens system and the inner tube are arranged to perform the function of an optical fiber collimator. The inner tube is made from an optical fiber compatible material. Examples of the optical fiber compatible material include ruby, quartz, and sapphire.

Abstract: A compensated higher order waveplate is constructed of substrates. In one embodiment, a first substrate is a n? waveplate and the second substrate is a (n+?)? waveplate. The substrates are oriented so that their principle axes of retardation are orthogonal. n? is a base retardation of a waveplate and ?? is an incremental retardation. The incremental retardation produces a desired amount of retardation of a lightwave passing through the compensated higher order waveplate. Retarder material used to produce the base retardation is approximately ½ a desired thickness of the waveplate. Multiple waveplates are combined to produce any of wavelength band specific retarders and multiple non contiguous wavelength band specific retarders.

Abstract: The present invention relates to a ruggedized optical fiber collimator. An embodiment of the present invention includes a housing, an optical fiber, a collimating lens system comprising at least one lens, and an inner tube. The optical fiber extends into the housing through the inner tube. The housing houses the inner tube and the collimating lens system. The optical fiber terminates in the housing. The housing, the optical fiber, the collimating lens system and the inner tube are arranged to perform the function of an optical fiber collimator. The inner tube is made from an optical fiber compatible material. Examples of the optical fiber compatible material include ruby, quartz, and sapphire.

Abstract: This invention relates to a variable optical power splitter with an integrated variable optical attenuator. According to an embodiment of this invention, a first polarizing beam splitter separates an incident light beam into two substantially mutually orthogonally polarized light beams. Rotator cells are arranged to change the polarization directions of the polarized light beams to control the power splitting ratio between a first output and a second output. A second polarizing beam splitter diverts a first and a second predetermined polarization components in the polarized light beams to the first and the second outputs respectively. At each output, there are rotator cells and a polarizing beam splitter. These rotator cells changes the polarization directions of the diverted light beams to control the attenuations to the diverted light beams. The polarizing beam splitter combines predetermined polarization components of the diverted light beams into a single light beam at the output.

Abstract: The present invention relates to an optical fiber system that includes an integrated optical fiber collimator with a built-in photodetector. The integrated optical fiber collimator according to an embodiment of the present invention includes a housing, an optical fiber, and a collimating lens system having at least one lens that is in optical communication with an optical fiber, a beams splitter in the light path in the housing to divert a portion of the light traveling inside the housing to at least one photodetector.

Abstract: The present invention relates to optical fiber system that employs an improved optical fiber collimator. The improved optical fiber collimator includes a housing, optical fiber, and a lens system of one or more lenses. The improved optical fiber does not require the fiber ferrule employed in a conventional optical fiber collimator design.

Abstract: The present invention relates to an optical fiber collimator with applications including optical fiber communication systems. An embodiment of the present invention includes a housing, optical fiber, and a lens system having at least one lens. The embodiment does not require the fiber ferrule employed in a conventional optical fiber collimator.

Abstract: The present invention relates to an optical fiber collimator with a built-in photodetector. An embodiment of the present invention includes a housing, an optical fiber, and a collimating lens system having at least one lens that is in optical communication with an optical fiber, a beams splitter in the light path in the housing to divert a portion of the light traveling inside the housing to at least one photodetector.

Abstract: The present invention relates to a polarization control apparatus. An embodiment of the present invention comprises a first and a second polarizing beam displacers, and a first and a second liquid crystal cells with both cells being responsive to external signals. The first polarizing beam displacer separates an input light beam into two substantially mutually orthogonal polarized light beams. Each of the two polarized light beams is rotated in polarization by at least one of the liquid crystal cells into a rotated polarized light beam. The second polarizing beam splitter combines substantially predetermined polarization components of the two rotated polarized light beams into an output light beam. Optionally, optically fiber collimators are disposed to provide the input light beam and receive the output light beam. The present invention may be adapted to multiple optical channel applications.

Abstract: A compensated higher order waveplate is constructed of substrates. In one embodiment, a first substrate is a n&lgr; waveplate and the second substrate is a (n+&Dgr;)&lgr; waveplate. The substrates are oriented so that their principle axes of retardation are orthogonal. n&lgr; is a base retardation of a waveplate and &Dgr;&lgr; is an incremental retardation. The incremental retardation produces a desired amount of retardation of a lightwave passing through the compensated higher order waveplate. Retarder material used to produce the base retardation is approximately ½ a desired thickness of the waveplate. Multiple waveplates are combined to produce any of wavelength band specific retarders and multiple non contiguous wavelength band specific retarders.

Abstract: A Virtually Imaged Phased Array (VIPA) contains a separate, precision-machined optical surface that forms one surface of the internal etalon and a boundary of the “radiation window,” in order to more easily achieve the optical-mechanical tolerances necessary for desired performance. VIPA design known to the prior art requires that a high reflective (mirror) optical coating be applied to a portion of a face of a plate of glass with a very sharp and well controlled boundary line across the surface while the remainder has an AR coating. This is difficult under the state of the art. In the disclosed VIPA, the required sharp boundary can be the machined physical edge of a plate of material (instead of the edge of a coating), which can be very precisely cut and controlled using common optical techniques. The disclosed VIPA is more easily manufactured than those known to the state of the art, and therefore is practical for applications such as the dispersing element in a chromatic dispersion compensator.

Abstract: A laser beam attenuator and a method of attenuating a laser beam are disclosed. The laser beam attenuator includes first and second prisms, a beam dump, and a light absorbing body. An input laser beam partially refracts and partially reflects at a first surface of the first prism to form first refracted and reflected laser beams. The first reflected laser beam partially refracts and partially reflects at a second surface of the second prism to form second refracted and reflected laser beams. The beam dump and the light absorbing body absorb the first and second refracted laser beams. Thus, the second reflected laser beam forms an attenuated laser beam.

Abstract: An imaging method creates a two-dimensional image of a voltage distribution or a capacitance distribution across a surface of a substrate under test using an electro-optic modulator which is positioned and biased with respect to the surface of the substrate. The method involves a first coarse offsite calibrating step to compensate for nonuniformities in the light emerging from the modulator. Then, for each successive portion of the substrate over which the modulator is to detect characteristics of the substrate, the system undergoes a modulator relocating step, a modulator levelling step, a modulator gapping step, a fine onsite calibrating step, and a measuring step.