摘要:
Systems and methods for steering a complex, spatially-modulated incident beam of coherent light to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) a reflective element, locatable proximate a first focal plane of the incident beam, (2) a rotational steering mechanism, coupled to the reflective element, that orients the reflective element according to a desired rotational angle to steer the incident beam in a desired direction and (3) a refractive element that refracts the beam reflected from the reflective element to create a second focal plane for the beam, the HMC locatable proximate the second focal plane to receive the beam at a location thereon that is a function of the desired direction.
摘要:
Systems and methods for steering an optical path to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) first and second reflective elements locatable to receive and reflect a complex, spatially-modulated incident beam of light, (2) a reflective element steering mechanism, coupled to the first and second reflective elements, that moves the first and second reflective elements to steer the incident beam in a desired direction and (3) an HMC rotating mechanism, couplable to the HMC, that rotates the HMC about an axis thereof, the reflective element steering mechanism and the HMC rotating mechanism cooperating to cause the incident beam to illuminate a location on a plane of the HMC that is a function of a movement of the first and second reflective elements and a rotational position of the HMC.
摘要:
Systems and methods for steering an optical path to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) a refractive element that receives a complex, spatially-modulated incident beam of light, (2) first and second reflective elements locatable to receive and reflect the incident beam in a Fresnel region thereof and (3) a reflective element steering mechanism, coupled to the first and second reflective elements, that moves the first and second reflective elements in tandem to steer the incident beam with respect to the HMC thereby to cause the incident beam to illuminate a location on the HMC that is a function of a movement of the first and second reflective elements.
摘要:
Systems and methods for steering a complex, spatially-modulated incident beam of light from a spatial light modulator to gain access to data locations in a holographic memory cell (HMC). One of the systems includes (1) a primary beam steering system that receives the incident beam of light from the spatial light modulator and produces a resulting beam of light, wherein the primary beam steering system traverses the resulting beam of light across a plane of the HMC in increments having a first magnitude and 2) a fine-control translation mechanism, coupled to the spatial light modulator, that translates the spatial light modulator relative to the primary beam steering system to cause the resulting beam of light to traverse the plane of the HMC in increments having a second magnitude smaller than the first magnitude.
摘要:
Embodiments of the invention include a data receiving apparatus and method of a holographic or other page-wise memory system for processing information read from the memory system's storage medium. The data apparatus includes a multi-dimensional array of pixel elements comprised of pixel detectors and corresponding pixel circuit. The pixel detectors detect information such as light information representing data stored in the memory system. The pixel circuits determine a value representative of the information detected by the individual pixel detectors. Additionally, the apparatus includes active processing circuitry advantageously fabricated in conjunction with the pixel circuits to provide additional "on-chip" processing capabilities, including analog inter-pixel processing. The advantageous arrangement of the additional processing improves processing times, reduces the unprocessed data flow out of the apparatus, and reduces circuitry design space and cost.
摘要:
Systems and methods for steering a complex, spatially-modulated incident beam of coherent light to gain access to data locations in a holographic memory cell (HMC). One of the systems includes: (1) a reflective element, locatable proximate a first focal plane of the incident beam, (2) a rotational steering mechanism, coupled to the reflective element, that orients the reflective element according to a desired rotational angle to steer the incident beam in a desired direction and (3) a refractive element that refracts the beam reflected from the reflective element to create a second focal plane for the beam, the HMC locatable proximate the second focal plane and rotatable about an axis of a plane thereof to receive the beam at a location thereon that is a function of the desired direction and an angular position of the HMC.
摘要:
Feedback is employed in a holographic memory system to facilitate rapid access to information in a stored data page. This feedback technique provides compensation for thermal, optical and/or mechanical variations in the system components that tend to interrupt the projection of a data page image on a sensor array. A page indicator or mark is stored in a holographic storage medium with a page of data such that, during playback, a quality, e.g., intensity, of its projected image is indicative of the quality of the corresponding projected data page image. A corresponding page indicator sensor is employed with the associated sensor array to detect the quality of a projected page indicator image. The projected data page image can then be read by sensor elements of the detector based on the detected quality of the page indicator image. Such a detector can be implemented in an active pixel sensor (APS) array with the page indicator sensor being implemented as a region of the APS array. Registration of the sensor array elements with respect to projected data pixels of the data page image can also be aligned to an absolute or substantially nearest pixel alignment by a similar feedback technique.
摘要:
Embodiments of the invention include an off-axis amplitude and phase encoding optical system, apparatus and method of storage in which a holographic optical element (HOE) is used advantageously to reconstruct optical elements typically used to phaseencode an object beam emanating from a spatial light modulator (SLM). The optical system includes a spatial light modulator (SLM) such as a digital micro-mirror device (DMD), a data storage device such as a holographic memory cell (HMC), and the holographic optical element (HOE) for duplicating the phase-encoding functions typically performed on an object beam emanating from the SLM prior to alignment with the holographic memory cell (HMC). Conventionally, a phase mask along with one or more optical elements comprising a four-F lens system typically are needed to phase encode the amplitude-encoded light pattern that propagates from the SLM. According to embodiments of the invention, a holographic optical element (HOE) replaces the phase mask and other optical elements and performs the necessary phase encoding on the amplitude-encoded beam prior to the beam being aligned with the holographic memory cell (HMC) for storage therein. Once generated, the holographic optical element (HOE) replaces the complicated phase mask and conventional four-F lens system arrangement typically used to phase-encode an amplitude-encoded object beam emanating from the spatial light modulator (SLM) of the off-axis amplitude and phase encoding optical system.
摘要:
Embodiments of the invention include a method and apparatus for determining values for data reproduced or retrieved from data storage media such as in holographic memory systems. The method includes initially approximating the value of data members retrieved initially from the data storage medium of interest (e.g., by their intensity levels based on an absolute scale), using those approximations collectively to establish one or more threshold levels for defining ranges for the data values to be determined, and determining values for the retrieved data members by comparing the initial data value approximations of the retrieved data members to the established threshold levels. Alternatively, the threshold level(s) are set initially and adjusted iteratively based on the initial approximations of the individual data members until a final established threshold level is established. Advantageously, embodiments of the invention reduce data encoding overhead by using data members to establish comparative threshold levels for the determination of their intended values.
摘要:
Feedback is employed in a holographic memory system to facilitate rapid access to information in a stored data page. This feedback technique provides compensation for thermal, optical and/or mechanical variations in the system components that tend to interrupt the projection of a data page image on a sensor array. A page indicator or mark is stored in a holographic storage medium with a page of data such that, during playback, a quality, e.g., intensity, of its projected image is indicative of the quality of the corresponding projected data page image. A corresponding page indicator sensor is employed with the associated sensor array to detect the quality of a projected page indicator image. The projected data page image can then be read by sensor elements of the detector based on the detected quality of the page indicator image. Such a detector can be implemented in an active pixel sensor (APS) array with the page indicator sensor being implemented as a region of the APS array. Registration of the sensor array elements with respect to projected data pixels of the data page image can also be aligned to an absolute or substantially nearest pixel alignment by a similar feedback technique.