摘要:
An angular multiplexing apparatus for a holographic storage medium. The angular multiplexing apparatus includes a reconstructing reference beam generator, translated in parallel to a number of positions, for generating a number of reconstructing reference beams which propagate in parallel to one another at the positions, respectively, and a mirror array having a plurality of planes of reflection for generating a plurality of reflected beams which are converged into a reconstructing position of the holographic storage medium.
摘要:
In a storing mode of an apparatus for sequentially storing and retrieving digital page data, a first and second complex reference beams and a modulated and second signal beams converge on a first/second location to generate a sequence of first and second interference patterns to be sequentially stored on a holographic medium. A shift selectivity of the first complex reference beam is larger than that of the second complex reference beam so that the second interference pattern is used as a servo pattern to sequentially determine where the first interference patterns have been stored.
摘要:
A holographic ROM reader having a servo control is disclosed. The holographic ROM reader includes an objective lens for focusing light reflected from a storage medium, a pinhole plate provided with a pinhole, a diffraction grating, embedded into the pinhole of the pinhole plate, for diffracting the light focused by the objective lens to produce 0th order diffracted light, +1st order diffracted light and −1st order diffracted light therethrough, a photo detector for detecting the amounts of the 0th order, the +1st order and the −1st order diffracted light, and a servo controller for comparing an amount of light of an overlapped area of the 0th order diffracted light and the +1st order diffracted light with an amount of light of an overlapped area of the 0th order diffracted light and the −1st order diffracted light to control the position of the objective lens to pass the light through a center of the diffraction grating if the amounts of light are not identical to each other.
摘要:
A tilt servo apparatus for use in a ROM system includes means for generating a reconstructing beam to be projected onto a digital storage medium to generate a reflected beam; a holographic plate for storing a first and a second hologram and diffracting the reflected beam with the first and the second hologram to generate a first and a second holographic diffracted beam, respectively; a first and a second detector for generating a first and a second detected signal by detecting the first and the second holographic diffracted beam, respectively; means for generating a tilt servo signal based on the first and the second detected signal; and means for compensating a tilt error of the digital storage medium by using the tilt servo signal.
摘要:
In a holographic recording apparatus having a hologram medium for storing an interference pattern between a reference beam and a modulated signal beam, a double-layered mask for modulating a signal beam with data to generate the modulated signal beam has a first and a second opaque film and a transparent plate inserted therebetween. The first and the second opaque film face each other and have a plurality of first and second recording tracks, respectively. The first and the second recording tracks are alternately arranged, wherein the data to modulate the signal beam therewith are alternately embedded along the first and the second recording tracks such that one of two neighboring recording tracks is one of the first recording tracks and the other is one of the second recording tracks.
摘要:
Before recording data included in a data mask on a holographic medium, the data mask and the holographic medium are aligned by an aligner, which includes a beam supplying unit for supplying an incident laser beam; a transferring unit for receiving the incident laser beam and producing a focused laser beam; a reflecting unit including the holographic medium for receiving the focused laser beam through a pinhole and then reflecting the received laser beam back to the pinhole, wherein the reflected laser beam passing through the pinhole returns to the transferring unit and then is converted into a return laser beam by the transferring unit; and a detecting unit for checking the amount of the return laser beam to determine whether the pinhole and the holographic medium are aligned or not.
摘要:
Provided are optical information processing apparatus and method. In the optical information processing apparatus and method, when the recording regions in which optical information is recorded in an angular multiplexing scheme overlap with each other, a recording angle and a recording position for optical information is adjusted so as to improve reproducing efficiency of readout beams reproduced from the overlap recording regions, so that heights of “null” for diffraction energy reproduced from the recording regions and overlap recording regions can be lowered. Accordingly, it is possible to reduce crosstalk noise during the recording and producing of the optical information and to improve optical information recording quality and reproducing efficiency
摘要:
A holographic storage system includes a beam supplying unit for supplying an incident beam including data read from a plurality of tracks on a holographic medium; a transferring unit for receiving the incident beam and producing a focused beam; a tracking servo unit for receiving a first portion of the focused beam through a plurality of pinholes and reflecting a second portion of the focused beam back to the transferring unit through a reflecting section simultaneously, wherein the tracking servo unit moves the transferring unit or the pinholes to adjust the amount of the first portion of the focused beam to thereby retrieve data from a target track, and wherein the second portion of the focused beam reflected back to the transferring unit is converted into a return beam by the transferring unit; and a focusing servo unit for compensating for vertical movements of the holographic medium.
摘要:
In order to pick up a digital storage medium including a holographic storage medium and a reflective storage medium, a first and a second beam each of which has a different wavelength are used and a reflected beam and a reconstructed signal beam are propagated through a propagation path, wherein the first beam is reflected by the digital storage medium to generate the reflected beam and the second beam is diffracted by a holographic interference pattern in the holographic storage medium to generate the reconstructed signal beam. A polarizing beam splitter is used to split the reflected beam from the propagation path while a laser line mirror is used to separate the reconstructed signal beam from the propagation path.
摘要:
In a storing mode of an apparatus for storing and retrieving a sequence of digital page data, a first/second complex reference beam and a modulated signal beam converge on a storing location to generate a sequence of first/second interference patterns to be sequentially stored on a holographic medium. A shift selectivity of the first complex reference beam is larger than that of the second complex reference beam so that the second interference pattern is used as a servo pattern to sequentially determine where the first interference patterns have been stored.