Abstract: The present invention relates to a system and method for tunable dispersion compensation that uses a first reflective surface and a second reflective surface. The first reflective surface has a gradient reflective index and receives an input signal at an incident position. The first reflective surface and the second reflective surface process the input signal according to a dispersion function that is based at least in part upon the incident position of the input signal.

Abstract: An apparatus for processing an optical signal includes a tunable optical element and a reflective element. The tunable optical element receives a first input signal, at an incidence angle, and a second input signal. The tunable optical element separates the first input signal into a first beam having a first optical path length and a second beam having a second optical path length. The difference between the first optical path length and the second optical path length is based in part upon the incidence angle of the first input signal. The tunable optical element separates the second input signal into a third beam and a fourth beam. The reflective element reflects the first beam, the second beam, the third beam, and the fourth beam such that at least a portion of the beams interfere to produce an output signal. The output signal comprises wavelength channels of the first input signal combined with wavelength channels of the second input signal.

Abstract: An apparatus for processing an optical signal includes a tunable optical element and a reflective element. The tunable optical element receives an input signal at an incidence angle and separates the input signal into a first beam having a first optical path length and a second beam having a second optical path length. The difference between the first optical path length and the second optical path length is based at least in part upon the incidence angle of the input signal. The reflective element reflects the first beam and the second beam such that the first beam interferes with the second beam to produce a first output signal and a second output signal. The first output signal comprises a first subset of wavelength channels from the input signal and the second output signal comprises a second subset of wavelength channels from the input signal.

Abstract: A method and apparatus for optical wavelength routing separates even and odd optical channels from an input WDM signal. The input beam is first converted to at least one pair of orthogonally-polarized beams. A split-mirror resonator has a front mirror with two regions having different reflectivities, and a reflective back mirror spaced a predetermined distance behind the front mirror. Each of the orthogonally-polarized beams is incident on a corresponding region of the front mirror of the split-mirror resonator. A portion of each beam is reflected by the front mirror, which the remainder of each beam enters the resonator cavity where it is reflected by the back mirror back through the front mirror. The group delay of each reflected beam is strongly dependent on wavelength. The two reflected beams from the resonator are combined and interfere in a birefringent element (e.g., a beam displacer or waveplates) to produce a beam having mixed polarization as a function of wavelength.

Abstract: An optical wavelength router separates an input signal into two complementary output signals. A beamsplitter of the wavelength router separates the input signal into a first beam and a second beam. A first resonator reflects the first beam producing a group delay that is dependent on wavelength. Similarly, a second resonator reflects the second beam. The center wavelength of the second resonator is offset relative to that of the first resonator by one half of the free spectral range of the first resonator, so that the resonance frequencies of the second resonator are matched to the anti-resonance frequencies of the first resonator. The beams reflected by the resonators interfere within the beamsplitter to produce two output signals containing complementary subsets of the spectrum of the input signal (e.g., even optical channels are routed to a first output port and the odd optical channels are routed to a second output port).

Abstract: An interferometer receives an input optical signal and outputs a signal after changing at least the dispersion of said signal. At least portions of the interferometer are adjustable to adjust at least a first dispersion parameter. Examples of dispersion parameters which are adjustable include dispersion magnitude, center wavelengths and waveshapes or slopes. Preferably the dispersion in the output signal is substantially reduced or substantially eliminated, compared to the dispersion of the input signal. By providing for adjustability of one or more dispersion parameters, a dispersion compensator can be appropriately adjusted for use in a variety of applications.

Abstract: An optical memory for storing and/or reading data on an optical disk. The optical disk incorporates a material in which holographic gratings can be created, and subsequently detected, at plural locations within the disk by an electro-optical head. Creation and detection of holographic gratings with variable diffraction efficiency is possible with the electro-optical head. Multiple holographic gratings can also be created at each one of the plural locations via a beam of light which has a different wavelength or point of focus. These data elements can be read by the electro-optical head using a beam of light sequentially varied in wavelength or point of focus to correspond to the multiple holographic gratings to be recorded.

Abstract: A method and apparatus for optical wavelength routing separates even and odd optical channels from an input WDM signal. The input beam is first converted to at least one pair of orthogonally-polarized beams. A split-mirror resonator has a front mirror with two regions having different reflectivities, and a reflective back mirror spaced a predetermined distance behind the front mirror. Each of the orthogonally-polarized beams is incident on a corresponding region of the front mirror of the split-mirror resonator. A portion of each beam is reflected by the front mirror, which the remainder of each beam enters the resonator cavity where it is reflected by the back mirror back through the front mirror. The group delay of each reflected beam is strongly dependent on wavelength. The two reflected beams from the resonator are combined and interfere in a birefringent element (e.g., a beam displacer or waveplates) to produce a beam having mixed polarization as a function of wavelength.

Abstract: A system of reproducing multiplexed holographic information from one master medium (100, 300, 400, 500, 600, 720) to another replicate medium (200, 310, 410, 510, 610, 730) simultaneously reads out the information from all multiplexed master holograms within the master medium. The replica has different phase and amplitude distributions from the master medium containing a plurality of multiplexed holograms (420, 520) though both the replica and the master contain the identical holographic information of the original objects.

Abstract: An optical memory for storing and/or reading data on an optical disk. The optical disk incorporates a material in which holographic gratings can be created at plural locations within the disk. An electro-optical head which is capable of creating these holographic gratings at any one of the plural locations is employed. The head is additionally capable of detecting the presence or absence of a holographic grating at any one of these plural locations. The presence of the holographic grating could indicate a first binary state and the absence of the holographic grating indicate a second state. Alternately, the electro-optical head could be used to vary the diffraction efficiency of the holographic gratings during their creation. In that case, the head would also be capable of detecting this variation in efficiency and produce a proportional detection signal. This signal would be used as an indicator of the value of the stored data element.

Abstract: A method and apparatus for optical wavelength routing separates even and odd optical channels from an input WDM signal. The input beam is first converted to at least one pair of orthogonally-polarized beams. A split-mirror resonator has a front mirror with two regions having different reflectivities, and a reflective back mirror spaced a predetermined distance behind the front mirror. Each of the orthogonally-polarized beams is incident on a corresponding region of the front mirror of the split-mirror resonator. A portion of each beam is reflected by the front mirror, while the remainder of each beam enters the resonator cavity where it is reflected by the back mirror back through the front mirror. The group delay of each reflected beam is strongly dependent on wavelength. The two reflected beams from the resonator are combined and interfere in a birefringent element (e.g., a beam displacer or waveplates) to produce a beam having mixed polarization as a function of wavelength.

Abstract: A method and a compact apparatus to read shift-multiplexed holograms on a storage medium without the need for any lenses, and without the need for moving the storage medium. The shift-multiplexed holograms have centers at different locations. The apparatus can generate an array of diverging spherical waves of reference beams, each for illuminating one of the holograms. Each hologram is read as an image on a detector array by illuminating that hologram with a corresponding diverging spherical wave of reference beam. Different holograms can be read by illuminating the medium with a different diverging spherical reference beam. The diverging beams can be from an array of sources, or can be from switching one source.

Abstract: An apparatus and a method for recognizing the gesture of the image of a player by identifying a gesture from a set of specific pre-defined gestures. In one embodiment, the method includes the steps of retrieving a background image that does not include the player's image, and a current image that includes the player's image and at least a portion of the background image. Then the method removes at least a portion of the background image from the current image to generate the player's image, which is mapped directly to a number of templates to generate a number of template outputs. Finally, the method analyzes the template outputs to identify the specific pre-defined gesture that corresponds to the gesture in the image.

Abstract: A method and a compact apparatus to read shift-multiplexed holograms on a storage medium without the need for any lenses, and without the need for moving the storage medium. The shift-multiplexed holograms have centers at different locations. The apparatus can generate an array of diverging spherical waves of reference beams, each for illuminating one of the holograms. Each hologram is read as an image on a detector array by illuminating that hologram with a corresponding diverging spherical wave of reference beam. Different holograms can be read by illuminating the medium with a different diverging spherical reference beam. The diverging beams can be from an array of sources, or can be from switching one source.

Abstract: A method and a system to re-align onto a detector array a holographic image of a Fourier region hologram stored in a medium, with the medium spinning around a first axis, and the hologram being generated by a reference beam and a signal beam. In generating the hologram, the reference beam is incident on the medium with respect to a second axis at a second-axis-incident angle, and a third axis at a third-axis-incident angle, such that the holographic image of the hologram when reproduced by the reference beam is aligned onto the detector array. Also, the three axes are substantially orthogonal to each other. As the medium spins, the medium's orientation can change through tilting with respect to the second and the third axes so that the holographic image when reproduced by the reference beam is not aligned onto the detector array.

Abstract: In one embodiment, a fingerprint sensing system includes a sheet prism having a sensing surface and a number of prismlets positioned opposite to the sensing surface. Each prismlet has an entrance surface and an exit surface, and is adjacent to another prismlet. The width of the sheet is more than ten times the maximum thickness of any one of the prismlets. When a finger is positioned on the sensing surface, a portion of the radiation entering a number of the entrance surfaces and incident at the sensing surface is reflected through total internal reflection. The reflected radiation emits from a number of the exit surfaces to create an image of the fingerprint. In another embodiment, the system further includes a second sheet prism stacked together with the previously described sheet prism. The second sheet prism has a flat surface and a number of prismlets positioned opposite to the flat surface, which faces the prismlets of the previously described sheet prism.

Abstract: A photorefractive pirouette display device can produce the sonogram of speech sounds by incorporating the short-time Fourier spectrum of speech waves as the input. The device requires a coherent source of optical radiation which can be obtained for a variety of different lasers. A photorefractive circuit is used to display a time-dependent signal, beam. An analog signal is imposed on the beam as temporal modulations on its intensity and/or phase, the pump beam is a plane wave constant amplitude. The signal beam interferes with the pump beam in the photorefractive crystal, the resultant intensity modulation pattern nonuniformly excites the charge carriers in the crystal. The excited charge carrier migrate in the crystal to form a microscope electric field, which produces an index grating in the crystal due to the Pockels effect. The crystal is rotating continually with angular velocity. The pump beam diffracts off of the holographic grating and reconstructs the signal beam.