Abstract: In the present invention, a volume holographic optical element is used as a pump coupler. The holographic coupler allows at least one pump wavelength to be coupled into the laser medium. The direction of the pump beam onto the coupler is not co-linear with the direction of the signal beam out of the coupler. The invention further provides the coupling of more than one pump wavelengths using a single holographic coupler element while maintaining the high isolation between pump and signal beam. The invention further provides a narrow-band reflection grating of various efficiencies for the signal beam (as part of the laser cavity).

Abstract: A method, system, and apparatus provide for the creation and use of a holographic filter. The holographic filter has multiple superpositioned holograms within a volume holographic medium. These superpositioned holograms synthesize a filter shape with multiple peaks at specified positions. The shape of the holographic filter matches a spectrum of a substance. The holographic filter may then be used (e.g., in a spectrometer) to simultaneously detect peaks in the spectrum of the matching substance.

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: The present invention provides a multi-channel turnable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings imprinted into a filter material, such as Lithium Niobate. In another embodiment, the filter comprises a bank of gratings imprinted on a thin-film filter. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack In another embodiment, the gratings are recorded by a phase masking method.

Abstract: Holographic methods for recording fast movies whose speed is limited by the laser pulse duration if the recording material has sufficient sensitivity to reliably record a frame of the fast event with a single pulse. The method we describe uses the selectivity of multiplexed holograms to resolve frames that are recorded with adjacent pulses. Specially designed pulse generators are used to generate the signal and reference pulse trains. We experimentally demonstrate the system by making movies of laser induced shock waves with a temporal resolution of 5.9 ns, limited by the pulse width of the Q-switched Nd:YAG laser used in the experiments.

Abstract: The invention combines fluorescent QDs and methods to dispense and detect them efficiently in a compact volume for a range of optical tagging applications. Micro-fluidic devices are used for mixing water-soluble fluorescent QDs in aqueous solutions to create a multi color fluorescent nano-optical tag, and gratings are used for spreading the spectral components of the fluorescent signal leading to an improvement in optical data storage capacity over prior art methods. The spectral signature of the tag is detected by a compact read-out head with a grating spectrometer. One way is to dispense the tag within the pits of a DVD or CD using an ink-jet nozzle and exciting them by a large range of wavelengths each shorter that the emission peak. The filters have a high immunity to prolonged exposure to high temperatures, and up to 41 infrared filters can be holographically recorded by spatial multiplexing of the substrate.

Abstract: An optical add/drop filter is formed using a hologram which is tuned to a wavelength in an optical signal. The diffraction condition of the hologram may be varied to vary the in add or drop content.

Abstract: The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings imprinted into a filter material, such as Lithium Niobate. In another embodiment, the filter comprises a bank of gratings imprinted on a thin-film filter. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.

Abstract: A temperature compensated apparatus for filtering light is comprised of a holographically recorded grating defined in a photosensitive layer for providing optical filtration for light incident on the grating with a predetermined angle of incidence, and an angulation means responsive to temperature for tilting the grating relative to the angle of incidence of the light as a function of temperature of the grating so that changes in the filtration by the grating compensate for changes in temperature of the grating to maintain effective filtration of the light approximately constant.

Abstract: A method and apparatus for increasing data storage capabilities by inserting quantum dots in the pits of disks like CD-RWs, DVDs, WORM disks, and CD-ROM disks, exciting them with a laser diode, and measuring their fluorescence is described. Carriers of different colors are placed in each pit via quantum dots. These dots are made up of multiple colors, or different shades of a color. The quantum dots are inserted using inkjet based technology, laser-induced technology, or holey fibers. A laser diode excites the dots, making them fluoresce, which is measured by a holographic multi-spectral filter (HMSF). The HMSF diffracts the collimated fluorescence before a lens focuses each spectral component onto a detector. A dichroic beam splitter is placed under the HMSF to prohibit the light from the laser diode to reach the detector yet allow the fluoresce through.

Abstract: A method, system, and apparatus provide for the creation and use of a holographic filter. The holographic filter has multiple superpositioned holograms within a volume holographic medium. These superpositioned holograms synthesize a filter shape with multiple peaks at specified positions. The shape of the holographic filter matches a spectrum of a substance. The holographic filter may then be used (e.g., in a spectrometer) to simultaneously detect peaks in the spectrum of the matching substance.

Abstract: A holographic imaging spectrometer, apparatus, and/or method enables the projection of a two-dimensional (2D) slice (having spectral information) of a four-dimensional (4D) probing object. A 4D probing source object is illuminated to emit an optical field. A holographic element having one or more recorded holograms receives and diffracts the optical field into a diffracted plane beam having spectral information. Collector optics (e.g., an imaging lens) focuses the diffracted plane beam having spectral information to a 2D slice (having spectral information) of the 4D probing source object. The focused 2D slice having spectral information is projected onto a 2D detector array surface. In addition, the holographic element may have multiple multiplexed holograms that are arranged to diffract light from the corresponding slice of the 4D probing source object to a non-overlapping section of the detector.

Abstract: A system of beam steering using electrical operation. A first system provides a grating and a liquid crystal material. When the liquid crystal is unenergized, there is a mismatch between the liquid crystal and the grating, causing the grating to diffract the light in a specified direction. The liquid crystal is energized to match its index of refraction to the grating. Then, the light is not diffracted by the grating, and hence travels in a different direction then it would when the liquid crystal was not energized. Another, finer system, forms electrically generated gratings using a liquid crystal material.

Abstract: A tunable optical filter includes a movable reflector, such as a three-dimensional microelectromechanical system (MEMS) actuated mirror and a plurality of holographic gratings each having a predetermined Bragg wavelength to select the wavelength to be filtered or dropped from broadband or wavelength-multiplexed input optical signals.

Abstract: The invention is related to the field of holographic methods for recording fast movies whose speed is limited by the laser pulse duration if the recording material has sufficient sensitivity to reliably record a frame of the fast event with a single pulse. The method we describe uses the selectively of multiplexed holograms to resolve frames that are recorded with adjacent pulses. Specially designed pulse generators are used to generate the signal and reference pulse trains. We experimentally demonstrate the system by making movies of laser induced shock waves with a temporal resolution of 5.9 ns, limited by the pulse width of the Q-switched Nd:YAG laser used in the experiments.

Abstract: The present invention provides a multi-channel tunable filter and methods for making such a filter. In one embodiment, the filter comprises a bank of gratings imprinted into a filter material, such as Lithium Niobate. In another embodiment, the filter comprises a bank of gratings imprinted on a thin-film filter. An optical read-head comprising a pair of lenses is configured to pass light from within an optical fiber carrying multiple wavelengths through an appropriate grating to extract or drop a specific wavelength. To ensure continuous data transmission, the filter is tuned to a wavelength by configuring the read-head to move in a hitless manner. In one embodiment, the gratings are recorded by the interference of two beams. A first plane wave reflects off a first mirror stack and a second plane wave reflects off a second mirror stack. In another embodiment, the gratings are recorded by a phase masking method.

Abstract: The present invention is a method and apparatus for a rotating, tunable, holographic drop filter connected to a fiber optic source. The filter uses a quasi phase-conjugate optical system for a drop-channel fiber coupling and WDM channels which are introduced to the system. The light from these channels is collimated and passed through a volume phase holographic material so that only one WDM channel is diffracted and the rest pass through the holographic material unaffected. A quasi phase-conjugate diffracted beam is generated by the optical system to reflect the diffracted channel back towards the holographic material. The reflected light is Bragg matched to the holographic material so that it is re-diffracted along a path identical to the original incident light beam. A free-space circulator may be used to direct the diffracted beam to a fiber optic collimator, which is different from the fiber optic collimator of the incident light beam.

Abstract: Embodiments of the present invention are directed to a method and apparatus for integrated optical wavelength division multiplexing using a bench of channel waveguides. In one embodiment, a plurality of waveguides is formed on a single substrate. Different waveguides are constructed to filter different channels carried on a single optical fiber. In one embodiment, optical fibers are attached to the ends of each waveguide. To select a specific filter, the fiber attached to the appropriate waveguide is used. In another embodiment, optical fibers are not attached to the ends of each waveguide. To select a specific filter, the reading head holding the fibers or the waveguide substrate is moved. In another embodiment, a voltage is supplied across the waveguide. Adjusting the voltage also adjusts which channel the waveguide will filter. In one embodiment, a circulator is used to extract the filtered channel.

Abstract: An identification system using biometric information of human body parts and a secret sequence code. In particular, biometric information of human body parts is used to form the secret sequence code. Specifically, a combination entry device recognizes user's fingerprints which are entered as a sequence. The fingerprints must be entered in the proper sequence in order to be recognized by the system. The fingerprints are preferably recognized using a fast technique with a low-probability level of rejection. While the sensor can be fooled for any one fingerprint. The use of a plurality of different fingerprints improves the identification capability. In particular, the combination of fingerprints in the proper order is necessary to undo the lock.

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.