Optical multiplexer and manufacturing method thereof, optical information recording apparatus and method, and optical information reproducing apparatus and method

Abstract

There is provided an optical multiplexer including: a substrate having a plurality of beam transmitting portions; and diffraction gratings diffracting beams irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion. Accordingly, it is possible to reduce an alignment error and manufacturing cost and to reduce the entire size of a recording apparatus or a reproducing apparatus.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

FIG. 1 is a perspective view illustrating an optical multiplexer according to an exemplary embodiment of the invention;

FIG. 2 is a partially expanded cross-sectional view illustrating beam transmitting portions of the optical multiplexer according to the exemplary embodiment of the invention;

FIGS. 3A and 3B are diagrams illustrating an out-of-plane multiplexing operation of the optical multiplexer according to the exemplary embodiment of the invention;

FIG. 4 is a flowchart illustrating a method of manufacturing the optical multiplexer according to the exemplary embodiment of the invention;

FIG. 5 is a diagram illustrating a configuration and an operating state of an optical multiplexer according to another exemplary embodiment of the invention;

FIG. 6 is a diagram illustrating a configuration and an operating state of an optical multiplexer according to another exemplary embodiment of the invention;

FIG. 7 is a diagram illustrating a configuration of an optical information recording apparatus according to an exemplary embodiment of the invention;

FIG. 8 is a flowchart illustrating an optical information recording method according to an exemplary embodiment of the invention;

FIG. 9 is a diagram illustrating a configuration of an optical information reproducing apparatus according to an exemplary embodiment of the invention; and

FIG. 10 is a flowchart illustrating an optical information reproducing method according to an exemplary embodiment of the invention.

Claims

1. An optical multiplexer comprising: a substrate having a plurality of beam transmitting portions; anddiffraction gratings diffracting a beam irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion.

2. The optical multiplexer according to claim 1, wherein the diffraction gratings are holographic interference fringes formed in photo-polymer filled in the beam transmitting portions.

3. The optical multiplexer according to claim 2, wherein the diffraction gratings are formed by spherical-wave beams and plane-wave beams.

4. The optical multiplexer according to claim 3, wherein the plane-wave beams are irradiated to the beam transmitting portions at different angles to form the diffraction gratings.

5. The optical multiplexer according to claim 1, wherein the substrate has a disc shape and the beam transmitting portions are spaced from each other along the circumference of the substrate.

6. The optical multiplexer according to claim 1, wherein the substrate has a bar shape and the beam transmitting portions are spaced from each other in the longitudinal direction of the substrate.

7. The optical multiplexer according to claim 1, wherein the substrate has a belt shape and the beam transmitting portions are spaced from each other in the traveling direction of the belt.

8. A method of manufacturing an optical multiplexer, the method comprising: irradiating a second beam at a first angle along with a first beam to a first beam transmitting photo-reactant to form a first diffraction grating in the first beam transmitting photo-reactant; andirradiating the second beam at a second angle different from the first angle along with the first beam to a second beam transmitting photo-reactant to form a second diffraction grating.

9. The method according to claim 8, wherein the first beam is a spherical-wave beam and the second beam is a plane-wave beam.

10. The method according to claim 8, wherein the first beam transmitting photo-reactant and the second beam transmitting photo-reactant are provided in a substrate.

11. The method according to claim 8, wherein the first angle and the second angle are different angles in a plane and the second beam is irradiated to the first and second beam transmitting photo-reactants at an angle out of the plane.

12. An optical information recording apparatus comprising: a light source;a beam splitter splitting a beam emitted from the light source;a signal beam optical system loading data to a beam split by the beam splitter and producing a signal beam;a reference beam optical system guiding another beam split by the beam splitter as a reference beam to an optical information storage medium; andan optical multiplexer multiplexing the reference beam at an angle in a plane and an angle out of the plane and guiding the multiplexed beams to the optical information storage medium.

13. The optical information recording apparatus according to claim 12, wherein the reference beam is a spherical-wave beam.

14. The optical information recording apparatus according to claim 13, wherein the optical multiplexer comprises a substrate having a plurality of beam transmitting portions; anddiffraction gratings diffracting beams irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion.

15. The optical information recording apparatus according to claim 14, wherein the beam transmitting portions convert the spherical-wave beam into a plane-wave beam with a different angle in the plane.

16. The optical information recording apparatus according to claim 15, wherein each beam transmitting portion converts the spherical-wave beam into a plane-wave beam with a different out-of-plane angle when the beam transmitting portion is moved to a position out of the predetermined plane.

17. An optical information recording method comprising: splitting a beam irradiated from a light source to two beams, using one split beam as a reference beam, and loading data to the other split beam to generate a signal beam;multiplexing the reference beam at a plurality of angles by the use of a diffraction grating, by irradiating the reference beam to a beam transmitting portion in which the diffraction grating is formed and moving the beam transmitting portion; andrecording the data in an optical information storage medium by irradiating the multiplexed reference beam and the signal beam to the optical information storage medium.

18. The optical information recording method according to claim 17, wherein the reference beam is converted into the spherical-wave beam by a lens and then is irradiated to the beam transmitting portion

19. The optical information recording method according to claim 17, wherein the reference beam is multiplexed at an angle in a plane and an angle out of the plane and then is irradiated to the optical information storage medium.

20. An optical information reproducing apparatus comprising: a light source;an optical system guiding a beam emitted from the light source to an optical information storage medium which stores multiplexed optical information;an optical multiplexer multiplexing the beam at an angle in a predetermined plane and an angle out of the plane and then guiding the multiplexed beam to the optical information storage medium; andan optical information detector detecting the optical information reproduced from the optical information storage medium by the multiplexed beam.

21. The optical information reproducing apparatus according to claim 20, wherein the optical multiplexer comprises: a substrate which is revolved with an external power and has a plurality of beam transmitting portions; anddiffraction gratings diffracting a beam irradiated to the beam transmitting portions at different angles, each diffraction grating being formed in the corresponding beam transmitting portion.

22. The optical information reproducing apparatus according to claim 21, wherein the beam irradiated to the optical multiplexer is a spherical-wave beam and the multiplexed beam emitted from the optical multiplexer is a plane-wave beam.

23. The optical information reproducing apparatus according to claim 22, wherein each beam transmitting portion generates the plane-wave beam with a different out-of-plane angle when the beam transmitting portion is moved at an out-of-plane position.

24. An optical information reproducing method comprising: generating a beam by irradiating a beam to a beam transmitting portion having a diffraction grating and generating the beam with a different angle from the diffraction grating by revolving the beam transmitting portion;irradiating the generated beams to an optical information storage medium in which optical information is stored and reproducing the optical information stored in the optical information storage medium by incident angles of the beams; anddetecting the reproduced optical information.

25. The optical information reproducing method according to claim 24, wherein the beam irradiated to the diffraction grating is a spherical-wave beam and the beam generated from the diffraction grating is a plane-wave beam.