Holographic digital data storage system compatible with holographic and reflective medium
View Patent ↗In a holographic digital data storage system, a light source generates a reference beam, a holographic optical element saves a plurality of interference patterns between the reference beam and a plurality of beams of specific sizes and a beam splitter splits each reproduced beam into a holographic signal beam and a holographic reference beam. A medium records an interference pattern between the holographic reference beam and the holographic signal beam and reflecting the holographic reference beam to generate a reflective information beam and, if only the holographic reference beam is illuminated, a displaying means displays a holographic reproduced beam for the holographic signal beam and detecting the reflective information beam.
1. A holographic digital data storage system compatible with a CD or DVD player, the system comprising:
a light source for generating a reference beam;
a holographic optical element for generating, if the reference beam is irradiated, a reproduced beam corresponding to one of a plurality of beams of specific sizes, wherein interference patterns between the reference beam and the plurality of beams of specific sizes are recorded in the holographic optical element, and wherein the reproduced beam is one of a holographic reproduced beam, a CD reproduced beam and a DVD reproduced beam;
means for splitting each reproduced beam into a reflected beam and a transmitted beam, wherein, if the holographic reproduced beam is generated from the holographic optical element, one of the reflected beam and the transmitted beam is defined as a holographic reference beam;
means for modulating the other of the reflected beam and the transmitted beam with an input signal to generate a holographic signal beam corresponding to the input signal;
means for, if only the holographic reference beam is irradiated onto a holographic digital data storage medium, displaying a holographic image reproduced from the holographic digital data storage medium and, if the CD or DVD reproduced beam is irradiated onto a CD or DVD medium, detecting a beam reflected from the CD or DVD medium.
2. The holographic digital data storage system of claim 1 , wherein interference patterns between the reference beam and the plurality of beams of specific sizes are recorded in the holographic optical element by using an angular multiplexing principle.
3. The holographic digital data storage system of claim 1 , further comprising means for shutting off either of the reflected beam and the transmitted beam which is not defined as the holographic reference beam to thereby make only the holographic reference beam to be irradiated onto the holographic digital data storage medium.
4. The holographic digital data storage system of claim 1 , wherein the reflected beam is modulated with the input signal by the modulating means to generate the holographic signal beam and the transmitted beam is used as the holographic reference beam.
5. The holographic digital data storage system of claim 1 , wherein the beam reflected from the CD or DVD medium is reflected by the splitting means toward the detecting means.