Lithograph apparatus comprising a mobile lens for producing digital holograms

• US 20040150802A1
• Filed: 03/30/2004
• Published: 08/05/2004
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: tesa scribos GmbH (Leonhard KURZ Stiftung & Company KG)
• Original Assignee: tesa scribos GmbH (Leonhard KURZ Stiftung & Company KG)
• Inventors: Lieber, Jorn, Dietrich, Christoph, Noehte, Steffen, Stadler, Stefan, Thomann, Robert
• Granted Patent: US 7,123,340 B2
• Time in Patent Office: Days
• US Class Current: 355/2
• CPC Class Codes: G03F 7/70383 Direct write, i.e. pattern is written directly without the use of a mask by one or multiple beams maskless lithography using a programmable mask G03F7/70291
• CPC Class Codes: G03H 1/08 Synthesising holograms, i.e. holograms synthesized from objects or objects from hologramsusing electric digital computers G06F; G06T
• CPC Class Codes: G03H 1/0891 Processes or apparatus adapted to convert digital holographic data into a hologram G03H1/2294 takes precedence

Abstract

The invention relates to a lithograph for producing digital holograms in a storage medium (4), having a light source (6, 10) for producing a write beam (12) with a predefined beam cross section, having a writing lens (14) for focusing the write beam (12) onto the storage medium (4) to be written, the writing lens (14) being arranged in a lens holder (16), and having drive means for the two-dimensional movement of the write beam relative to the storage medium. The technical problem of writing computer-generated holograms as quickly as possible and with little effort by means of optical lithography is solved in that a first drive device (18) is provided for moving the lens holder (16) substantially at right angles to the write beam (12) and in that the aperture of the writing lens (14) is smaller than the beam cross section of the write beam (12).

The invention also relates to a method for the lithographic production of a hologram in a storage medium.

Claims

1. A lithograph for producing digital holograms in a storage medium (4),

having a light source (6, 10) for producing a write beam (12) with a predefined beam cross section,

having a writing lens (14) for focusing the write beam (12) onto the storage medium (4) to be written, the writing lens (14) being arranged in a lens holder (16), and

having drive means for the two-dimensional movement of the write beam (12) relative to the storage medium (4), characterized

in that the drive means include a first drive device (18) for moving the lens holder (16) substantially at right angles to the write beam (12) and

in that the aperture of the writing lens (14) is smaller than the beam cross section of the write beam (12).

2. The lithograph as claimed in claim 1, characterized in that the drive device is formed as a linear motor or as a voice coil motor.

3. The lithograph as claimed in claim 1 or 2, characterized in that the mounting of the lens holder (16) is formed as solid-state bearings, ball bearings, sliding bearings, air bearings or magnetic bearings.

4. The lithograph as claimed in one of claims 1 to 3, characterized in that the lens holder (16) is linearly mounted and oscillates resonantly in one direction.

5. The lithograph as claimed in one of claims 1 to 3, characterized in that the lens holder (16″

) is rotationally mounted and oscillates resonantly in one rotational direction.

6. The lithograph as claimed in claim 4 or 5, characterized in that the lens holder (16, 16″

) oscillates at a frequency greater than 1 kHz.

7. The lithograph as claimed in one of claims 1 to 6, characterized

in that the first drive device (18) moves the writing lens (14) in a first direction of movement and

in that the drive means include a second drive device for moving the write beam (12) relative to the storage medium (4) in a second direction of movement transversely with respect to the first direction of movement.

8. The lithograph as claimed in claim 7, characterized in that the second drive device moves the lens holder (16, 16″

) of the writing lens (14) relative to the write beam (12).

9. The lithograph as claimed in claim 7, characterized in that the second drive device moves the light source (6, 10) and the lens holder (16, 16″

) of the writing lens (14) relative to the storage medium (4).

10. The lithograph as claimed in claim 7, characterized in that the second drive device moves the storage medium (4) relative to the light source (6, 10) and the lens holder (16,16″

) of the writing lens (14).

14. The lithograph as claimed in one of claims 11 to 13, characterized by one of the features of claims 1 to 10.

15. The lithograph as claimed in one of claims 1 to 14, characterized in that means are provided for adjusting the distance between the storage medium (4) and the writing lens (14, 14′

).

16. A method for the lithographic production of digital holograms in a storage medium, in particular with a lithograph as claimed in one of claims 1 to 14,

a write beam being focused onto the storage medium with the aid of a light source and a writing lens and being moved two-dimensionally relative to the storage medium with the aid of drive means,

in which the writing lens is moved relative to the optical storage medium in a first direction of movement substantially at right angles to the propagation direction of the write beam,

in which, within the range of movement of the writing lens, the aperture of the writing lens is illuminated substantially completely by the write beam, and

in which the hologram is written by introducing radiation energy point by point, the intensity of the write beam being controlled as a function of the position of the write beam on the storage medium.

17. The method as claimed in claim 16, in which the writing lens is moved relative to the storage medium in a second direction of movement transversely with respect to the first direction of movement.

18. The method as claimed in claim 16, in which the light source and the writing lens are moved relative to the storage medium.

19. The method as claimed in claim 16, in which the storage medium is moved relative to the light source and writing lens.

20. The method as claimed in one of claims 16 to 19, in which an orthogonal point pattern on the storage medium is scanned with the aid of the write beam.

21. The method as claimed in claim 20, in which the relative movement between write beam and storage medium in the second direction of movement is carried out discontinuously during the movement of the writing lens in the first direction of movement.

22. The method as claimed in claim 21, in which, during the movement of the write beam in the first direction of movement along the area of the storage medium to be written, the write beam is not moved in the second direction of movement and

in which, during the movement of the write beam in the first direction of movement along the area of the storage medium not to be written, the write beam is moved by one step transversely with respect to the first direction of movement.

23. The method as claimed in claim 20, in which, during the movement of the write beam in the first direction of movement, the write beam is moved continuously in the second direction of movement.

24. The method as claimed in one of claims 16 to 23, in which, with the aid of at least two writing lenses which are arranged beside each other and in particular are designed in the form of microlenses, holograms are written on the storage medium simultaneously.

25. The method as claimed in one of claims 16 to 24, in which the distance between the writing lens or writing microlens and the storage medium is set to write at various depths within the storage medium.

27. The microscope as claimed in claim 26, having one or more features of one of claims 2 to 15.

11. A lithograph for producing digital holograms in a storage medium (4),

having a light source (6, 10) for producing a write beam (12) with a predefined beam cross section,

having a writing lens (14′

) for focusing the write beam (12) onto the storage medium (4) to be written, the writing lens (14′

) being arranged in a lens holder (16′

), and

having drive means for the two-dimensional movement of the write beam (12) relative to the storage medium (4), characterized

in that the writing lens (14′

) is formed as a microlens.

12. The lithograph as claimed in claim 11, characterized in that at least two writing lenses (14′

) arranged beside each other are provided, the write beam (12) illuminating the at least two writing lenses (14′

) simultaneously.

13. The lithograph as claimed in claim 12, characterized in that the writing lenses (14′

) are arranged in an array.

26. A microscope for scanning an object (4),

having a light source (6, 10) for producing an observation beam (12) with a predefined beam cross section,

having a lens (14) for focusing the observation beam (12) onto the surface of the object (4), the lens (14) being arranged in a lens holder (16), and

having drive means for the two-dimensional movement of the observation beam (12) relative to the object (4), characterized

in that the drive means include a first drive device (18) for moving the lens holder (16) substantially at right angles to the observation beam (12) and

in that the aperture of the lens (14) is smaller than the beam cross section of the observation beam (12).