High-Speed Data Recording and Reading

Abstract

The present invention relates to a method of high-speed recording and reading data on or in a layer (10) of a first material and to a device for high-speed recording and reading data on or in a layer (10) of a first material using a laser source (19, a galvanometer (4) and a digital micromirror (5) adapted to emit multiple laser beams.

Claims

1-28. (canceled)

29. A method for high-speed recording data on or in a layer of a first material, the method comprising: providing a layer of the first material; and selectively illuminating a plurality of regions of the layer of the first material with laser light in order to selectively manipulate material at the plurality of regions of the layer of the first material; wherein the plurality of regions of the layer of the first material are selectively illuminated by means of a combination of a galvanometer scanner and a digital micromirror device.

30. The method of claim 29, wherein the laser light illuminating the plurality of regions of the layer of the first material passes, in this sequence, the galvanometer scanner and the digital micromirror device.

31. The method of claim 30, wherein the laser light passed from the galvanometer scanner illuminates only a section of a micromirror array of the digital micromirror device.

32. The method of claim 31, wherein the illuminated section amounts to less than 10% of the micromirror array of the digital micromirror device.

33. The method of claim 31, wherein the micromirror array of the digital micromirror device is scanned with the passed laser light by means of the galvanometer scanner.

34. The method of claim 30, wherein the laser light passed from the galvanometer scanner passes through collimating optics in order to align the laser light to a predetermined entrance angle with respect to the digital micromirror device.

35. The method of claim 29, wherein the laser light is provided by an ultra-short pulse laser.

36. The method of claim 29, wherein the layer of the first material is a ceramic material, which comprises at least one of: a metal nitride; a metal carbide; a metal oxide; a metal boride; or a metal silicide.

37. The method of claim 36, wherein the layer of the ceramic material is provided on a substrate, and wherein the substrate comprises a ceramic material different from the layer of the ceramic material.

38. The method of claim 37, wherein the layer of the ceramic material has a thickness no greater than 10 .Math.m.

39. The method of claim 37, wherein the substrate comprises at least 90% by weight of one or a combination of: Al.sub.2O.sub.3, TiO.sub.2, SiO.sub.2, ZrO.sub.2, ThO.sub.2, MgO, Cr.sub.2O.sub.3, Zr.sub.2O.sub.3, V.sub.2O.sub.3, a metal nitride, a metal carbide, a metal boride, or a metal silicide.

40. A device for high-speed recording data on or in a substrate, the device comprising: a laser source adapted to emit laser light; a galvanometer scanner adapted to pass the laser light; a digital micromirror device adapted to emit multiple laser beams formed from the passed laser light; a substrate holder for mounting the substrate; and focusing optics adapted for focusing each of the multiple laser beams emitted by the digital mirror device onto the substrate mounted on the substrate holder, wherein the multiple laser beams are adapted to encode recorded data on the substrate; wherein the galvanometer scanner is adapted to temporally distribute the laser light over the digital micromirror device.

41. The device of claim 40, wherein the galvanometer scanner is adapted to pass the laser light to only a section of a micromirror array of the digital micromirror device.

42. The device of claim 41, wherein the illuminated section amounts to less than 10% of the micromirror array of the digital micromirror device.

43. The device of claim 41, wherein the galvanometer scanner is adapted to scan the passed laser light onto the micromirror array of the digital micromirror device.

44. The device of claim 40, further comprising collimating optics in order to align the laser light distributed by the galvanometer scanner to a predetermined entrance angle with respect to the digital micromirror device.

45. The device of claim 40, wherein the laser source is an ultrashort pulse laser.

46. The device of claim 40, further comprising a reading device adapted to image the recorded data.

47. The device of claim 46, wherein the reading device comprises a further digital micromirror device.

48. The device of claim 46, further comprising a beam splitter between the digital micromirror device and the focusing optics, wherein the beam splitter allows for light emitted from the substrate to pass to the reading device.

49. The device of claim 46, further comprising a beam splitter between the galvanometer scanner and the digital micromirror device, wherein the beam splitter allows for light emitted from the substrate to pass to the reading device via the digital micromirror device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Preferred embodiments of the present invention will be further elucidated below with reference to the figures.

[0046] FIG. 1 shows a schematic view of a device for high-speed recording data according to a preferred embodiment.

[0047] FIG. 2 shows a schematic view of a device for high-speed recording data according to another preferred embodiment.

[0048] FIG. 3 shows a schematic view of a device for high-speed recording data according to another preferred embodiment.

[0049] FIG. 4 shows a schematic view of a device for high-speed recording data according to another preferred embodiment.

DETAILED DESCRIPTION

[0050] FIG. 1 shows a schematic illustration of a device for high-speed recording data on or in a layer of a first material according to a preferred embodiment of the present invention. The device comprises a laser source 1, a motorized attenuator 3a, a beam expander 2, an attenuation rotator 3b, a flat top beam shaper (preferably including collimating optics) 14, a galvanometer scanner 4, a digital micromirror device 5 adapted to emit multiple laser beams (of which only a single one is shown for simplicity), a substrate holder 11 for mounting a substrate 10, and focusing optics 9 adapted for focusing each of the multiple laser beams emitted by the DMD 5 onto the substrate 10 mounted on the substrate holder 11.

[0051] The galvanometer scanner 4 is configured to temporally distribute the laser power of the laser source 1 over the DMD 5. As explained above, the galvanometer device 4 is configured to simultaneously illuminate only a section of the micromirror array of the DMD 5. Since the angle of the laser beam emitted from the galvanometer scanner 4 depends on the position or area on the DMD 5 which the galvanometer scanner 4 aims at, the device preferably comprises collimating optics L1, L2 in order to align the laser light emitted by the galvanometer scanner 4 to a predetermined entrance angle with respect to the DMD 5. In order to properly illuminate the galvanometer scanner 4 by means of the laser source 1 a motorized attenuator 3a, a beam expander 2, an attenuation rotator 3b, and a flat top beam shaper (preferably including collimating optics) 14 may be provided.

[0052] The DMD 5 comprises multiple micromirrors arranged in an array (not shown) and is adapted to emit multiple laser beams (not shown) along either a first direction (i.e., for recording) or along a second direction for each micromirror being in an “off” state diverting those laser beams into a beam dump 6. For each micromirror being in an “on” state, a laser beam is emitted via a beam splitter 8 through a focusing optics 9 which may, for example, comprise standard microscope optics having a high numerical aperture, onto the substrate 10 being mounted on an XY positioning system (which may optionally also be movable along the Z direction).

[0053] As discussed above, the device may further comprise beam shaping optics 7 such as a matrix of laser zone plates or a spatial light modulator, which may be configured to allow for optical proximity control, to generate Bessel beams, or to create a phase-shift mask.

[0054] In the embodiment shown in FIG. 1, the device further comprises a reading device 12 configured to image the recorded data. The reading device in this embodiment comprises a further DMD (not shown) for addressing each pixel in reading mode. Alternatively, a high-resolution digital camera might be utilized for imaging the recorded pixels. The beam splitter 8 is positioned between the DMD 5 and the focusing optics 9 in order to allow for light emitted from the substrate 10 to pass to the reading device 12.

[0055] Illumination of the area to be imaged by the reading device 12 may be achieved by the laser source 1 for data recording or another laser source using the DMD 5 of the recording path for sequentially illuminating the pixels to be imaged and controlling both DMDs to address the same pixel at a time. In order to be able to resolve the tiny structures generated during recording, it is preferred to use a smaller wavelength for imaging. For example, the recording laser 1 may emit another harmonic having half of the recording wavelength. Alternatively, another laser source having a different wavelength may be present in the system. However, the illumination area might still be too small in this case. Thus, it may be preferable to utilize an additional light source for illuminating a much larger area and to merely use the reader’s DMD for scanning the pixels. The additional light source may be provided in the reading device 12 or external thereto. In the latter case, the illuminating light may be guided onto the surface to be imaged by means of the beam splitter 8 or an additional beam splitter (not shown) along the optical path.

[0056] In an alternative embodiment shown in FIG. 2, the beam splitter 8 is provided between the galvanometer scanner 4 and the DMD 5 and allows for light emitted from the substrate 10 to pass to the reading device 12 via the DMD 5. In this case, light emitted from the DMD 5 may be passed directly or via an additional mirror or beam splitter 13 to the focusing optics 9. The arrangement shown in FIG. 2 is particularly advantageous as the reading device 12 in this arrangement does not require its own DMD. Rather, a simple optical sensor may be sufficient because each pixel on the substrate 10 may be addressed via the DMD 5 along the recording beam. As described above, this alternative mimics the principle of a confocal microscope. Yet, instead of a scanning laser beam and a fixed pinhole the selected micromirrors define a path of a “movable pinhole”. Again, illumination may be achieved via the recording laser 1 and the recording path. It is, however, preferred to illuminate the substrate 10 with, e.g., UV light emitted from an additional light source via beam splitter 13 or an additional beam splitter along the optical path such as beam splitter 8.

[0057] FIGS. 1 and 2 show an embodiment wherein the beam shaping device 7 is transmitted by the laser light. However, in case the beam shaping device comprises, e.g., a spatial light modulator in reflection mode, the optical path may be altered as shown in FIG. 3. Again, the reading device 12 may be a sensor with its own DMD (see FIG. 3) or a simpler sensor without DMD (see FIG. 4), which utilizes the DMD 5 of the recording path.