METHOD FOR CONTROLLING A LASER DEVICE FOR A LASER-INDUCED REFRACTIVE INDEX CHANGE OF A POLYMER STRUCTURE

Abstract

A method is disclosed for controlling a laser device for a laser-induced refractive index change (URIC) of a polymer structure. The laser device is controlled by a control device such that it emits pulsed laser pulses in a shot sequence in a preset pattern into the polymer structure. The laser pulses are emitted with preset irradiation parameters for refractive index change of the polymer structure, wherein for adjusting an order of magnitude of the refractive index change, a spatial pulse distance of the laser pulses in the polymer structure is adapted and the further irradiation parameters are kept within respective preset irradiation parameter ranges.

Claims

1. A method for controlling a laser device for a laser-induced refractive index change (URIC) of a polymer structure, comprising: controlling the laser device using a control device such that the laser device emits pulsed laser pulses in a shot sequence in a preset pattern into the polymer structure, wherein the laser pulses are emitted with preset irradiation parameters for refractive index change of the polymer structure, and wherein for adjusting an order of magnitude of the refractive index change, a spatial pulse distance of the laser pulses in the polymer structure is adapted and the further irradiation parameters are kept within respective preset irradiation parameter ranges.

2. The method according to claim 1, wherein the respective order of magnitude of the refractive index change is preset for respective irradiation positions of the polymer structure, and wherein the spatial pulse distances are provided depending on the respective irradiation position in the preset pattern.

3. The method according to claim 1, wherein the further irradiation parameters are a numerical aperture, a temporal pulse length, an energy and a wavelength.

4. The method according to claim 1, wherein the spatial pulse distance is changed within a preset pulse distance range of values depending on the order of magnitude of the refractive index change to be achieved and the further irradiation parameters are kept constant at a respective value within the respectively preset irradiation parameter ranges.

5. The method according to claim 1, wherein the spatial pulse distance is varied along a scanning direction within a range between 1 nm and 10 μm, in particular between 10 nm and 1 μm, for adjusting the order of magnitude of the refractive index change.

6. The method according to claim 1, wherein the spatial pulse distance is changed between adjacent laser pulse paths within a range between 10 nm and 50 μm, in particular between 50 nm and 5 μm, for adjusting the order of magnitude of the refractive index change.

7. The method according to claim 1, wherein the irradiation parameter range of a numerical aperture between 0.1 and 0.7, in particular between 0.15 and 0.35, of a temporal pulse length between 10 fs and 1 ps, in particular between 30 fs and 75 fs, of an energy between 1 nJ and 120 nJ, in particular between 20 nJ and 80 nJ, and of a wavelength between 300 nm and 1500 nm, in particular between 900 nm and 1100 nm, is preset.

8. The method according to claim 1, wherein the laser pulses are emitted by a solid-state laser of the laser device, in particular a fiber laser or crystal laser.

9. The method according to claim 1, wherein the laser pulses are emitted into a biopolymer, in particular a cornea of a human or animal eye.

10. The method according to claim 1, wherein the laser pulses are emitted into a plastic polymer, in particular for generating an artificial lens.

11. The method according to claim 1, wherein the spatial pulse distance is adjusted by a pulse picker of the laser device and/or a scanning speed and/or a pulse path distance of adjacent laser pulse paths.

12. The method according to claim 1, wherein a Fresnel lens is generated in the polymer structure as the preset pattern.

13. A laser device with a control device, which is configured to perform a method according to claim 1.

14. The laser device according to claim 13, wherein the laser device comprises a solid-state laser, in particular a fiber laser.

15. The laser device according to claim 13, wherein the laser device is suitable to emit laser pulses in a wavelength range between 300 nm and 1500 nm, preferably between 900 nm and 1100 nm, at a respective pulse duration between 10 fs and 1 ps, preferably between 30 fs and 75 fs, and a repetition frequency of greater than 10 kHz, preferably between 100 kHz and 100 MHz.

16. The laser device according to claim 13, wherein the control device: comprises at least one storage device for at least temporary storage of at least one control dataset, wherein the control dataset or datasets include(s) control data for positioning and/or for focusing and/or for irradiation parameter adjustment of individual laser pulses; and includes at least one beam device for beam guidance and/or beam shaping and/or beam deflection and/or beam focusing of a laser beam of the laser device.

17. A computer program including commands, which cause a laser device with a control device to execute a method according to claim 1.

18. A non-transitory computer-readable medium, on which the computer program according to claim 17 is stored.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Further features of the invention are apparent from the claims, the figures and the description of figures. The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the description of figures and/or shown in the figures alone are usable not only in the respectively specified combination, but also in other combinations without departing from the scope of the invention. Thus, implementations are also to be considered as encompassed and disclosed by the invention, which are not explicitly shown in the figures and explained, but arise from and can be generated by separated feature combinations from the explained implementations. Implementations and feature combinations are also to be considered as disclosed, which thus do not comprise all of the features of an originally formulated independent claim. Moreover, implementations and feature combinations are to be considered as disclosed, in particular by the implementations set out above, which extend beyond or deviate from the feature combinations set out in the relations of the claims.

[0030] FIG. 1 depicts a schematic representation of a laser device according to an exemplary embodiment.

[0031] In the figures, identical or functionally identical elements are provided with the same reference characters.

DETAILED DESCRIPTION

[0032] FIG. 1 shows a schematic representation of a laser device 10 with a laser 12, in particular a solid-state laser, for the laser-induced refractive index change (URIC) of a polymer structure 14. In this embodiment, the polymer structure 14 can be a biopolymer, in particular an area of a cornea 14 of a human or animal eye 16. Alternatively, the polymer structure can also be a plastic polymer, into which an artificial lens is incorporated. A laser pulse sequence, a laser pulse distribution and irradiation parameters for the refractive index change of the cornea 14 can be preset in the form of control data by a control device 18, such that the laser 12 emits pulsed laser pulses to laser pulse positions preset by the control data with irradiation parameters provided by the control data to achieve the refractive index change. In particular, a pattern can be preset, which is to be generated in the cornea 14. Alternatively, the control device 18 can be a control device 18 external with respect to the laser device 10.

[0033] Furthermore, FIG. 1 shows that the laser beam 20 generated by the laser 12 can be deflected towards the eye 16 by means of a beam deflection device 22, namely a beam deflection apparatus such as for example a rotation scanner, to generate the refractive index change in the cornea 14 according to the preset pattern. The beam deflection apparatus 22 can also be controlled by the control device 18.

[0034] Preferably, the illustrated laser 12 can be a fiber laser, which is at least formed to emit laser pulses in a wavelength range between 800 nanometers and 1500 nanometers, preferably between 900 nanometers and 1100 nanometers, at a respective pulse duration between 10 femtoseconds and 90 femtoseconds, preferably between 30 femtoseconds and 75 femtoseconds, and a repetition frequency of greater than 10 kilohertz, preferably between 100 kilohertz and 100 megahertz.

[0035] Optionally, the control device 18 additionally comprises a storage device (not illustrated) for at least temporary storage of at least one control dataset, wherein the control dataset or datasets include(s) control data for irradiation parameter adjustment, positioning and/or focusing of individual laser pulses in the eye 16.

[0036] For adjusting an order of magnitude of the refractive index change in the cornea 14, it can be provided that the spatial pulse distances are varied depending on the respective irradiation position to for example generate a Fresnel lens in the cornea 14. With a great refractive index change to be achieved, a spatial pulse distance can thus for example be reduced, and with a small refractive index change to be achieved, a spatial pulse distance can be increased. Thereto, the spatial pulse distance can be varied within a preset pulse distance range of values, which can take values between 1 nanometer and 10 micrometers along a scanning direction and a value between 10 nanometers and 50 micrometers between adjacent laser pulse paths. In order to adjust the spatial pulse distance, the laser device 10 can comprise a pulse picker (not shown), by which individual laser pulses can be excluded from a laser pulse train, such that a larger pulse distance arises in particular with consistent scanning speed by the beam deflection device 22. Alternatively or additionally, the scanning speed of the beam deflection device 22 can be adapted to vary the spatial pulse distance, and/or a pulse path distance of adjacent laser pulse paths can be adjusted by the beam deflection device 22 to control the order of magnitude of the refractive index change.

[0037] The further irradiation parameters, which are preset for the laser-induced refractive index change, such as for example the numerical aperture, a temporal pulse length, an energy and a wavelength, can be kept within preset irradiation parameter ranges, preferably at a constant value within the preset irradiation parameter ranges. Therein, the irradiation parameter range of the numerical aperture can be between 0.1 and 0.7, preferably between 0.15 and 0.35, an irradiation parameter range of a temporal pulse length can be between 10 femtoseconds and 1 picosecond, preferably between 30 femtoseconds and 75 femtoseconds, an irradiation parameter range of an energy can be between 1 nanojoule and 120 nanojoules, preferably between 20 nanojoules and 80 nanojoules, and an irradiation parameter range of a wavelength can be between 300 nanometers and 1,500 nanometers, preferably between 900 nanometers and 1,100 nanometers.

[0038] Overall, the examples show how a change of the magnitude of the URIC effect can be adapted within a preset pattern by the invention without varying an energy of the laser device.