Recording medium and hologram reader

1. A recording medium comprising:

a storage part to hold a medium identifier intrinsic to each recording medium; and

a hologram generated using a reference beam modulated with the medium identifier,

wherein the hologram and the storage part are fixed on a surface of the recording medium.

2. The recording medium according to claim 1 , wherein the hologram includes a marker portion to measure a noise level in a part thereof.

3. A hologram reader comprising:

a reading unit to read a medium identifier from a storage part fixed on a surface of a recording medium, the medium identifier intrinsic to each of the recording medium; and

a generating unit to generate a regenerative beam from a hologram, the hologram recorded using a first reference beam modulated with the medium identifier and fixed on a surface of the recording medium, by applying a second reference beam modulated with the medium identifier to the hologram.

4. The hologram reader according to claim 3 , wherein the hologram includes a marker portion to measure a noise level in a part thereof.

5. The hologram reader according to claim 4 , further comprising:

a measuring unit to measure a noise level contained in the regenerative beam by referring to the marker portion and to output a measured result.

6. The hologram reader according to claim 5 , further comprising:

a connecting unit to connect the hologram reader to a database to be accessible; and

a recording unit to record relationally the medium identifier and the measured result of the noise level in the database,

wherein a history of the measured result of the noise level recorded in the database is subjected to a predetermined processing.

7. A hologram reading method comprising:

reading a medium identifier from a storage part fixed on a surface of a recording medium, the medium identifier intrinsic to each of the recording medium; and

generating a regenerative beam from a hologram, the hologram recorded using a first reference beam modulated with the medium identifier and fixed on a surface of the recording medium, by applying a second reference beam modulated with the medium identifier to the hologram.

8. The hologram reading method according to claim 7 ,

wherein the hologram includes a marker portion to measure a noise level in a part thereof.

9. A storage medium readable by a computer, the storage medium storing a program of instructions executable by the computer to perform a function for reading a hologram, the function comprising the steps of:

reading a medium identifier from a storage part fixed on a surface of a recording medium, the medium identifier intrinsic to each of the recording medium; and

generating a regenerative beam from a hologram, the hologram recorded using a first reference beam modulated with the medium identifier and fixed on a surface of the recording medium, by applying a second reference beam modulated with the medium identifier to the hologram.

10. The storage medium according to claim 9 , wherein the hologram includes a marker portion to measure a noise level in a part thereof.