Method and laser system for generating output laser pulses with an optical component with temperature-dependent power efficiency and associated computer program product

Patent metadata

Field	Value
Publication number	US-11942752-B2
Application number	US-202318448217-A
Country	US
Kind code	B2
Filing date	Aug 11, 2023
Priority date	Feb 17, 2021
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

A method for generating output laser pulses from input laser pulses includes causing the input laser pulses to temporally successively pass through an optical component with temperature-dependent power efficiency. The optical component is heated by the passing of the input laser pulses. The input laser pulses emerge from the optical component as output laser pulses. The method further includes calculating a current temperature or a current temperature difference of the optical component, or a temperature-dependent current parameter based on all preceding input laser pulses or output laser pulses that have contributed to the heating of the optical component, and setting a power of a current input laser pulse based on the calculated current temperature, or the calculated current temperature difference, or the calculated current parameter, so that an associated output laser pulse has a pulse energy that deviates from a predefined pulse energy by less than 5%.

First claim

The invention claimed is:

1. A method for generating output laser pulses from input laser pulses having previously known pulse energies and pulse spacings, the method comprising:
causing the input laser pulses to temporally successively pass through an optical component with temperature-dependent power efficiency, the optical component being heated by the passing of the input laser pulses, and the input laser pulses emerging from the optical component as output laser pulses for setting a respective pulse power component of the output laser pulses,
calculating a current temperature or a current temperature difference of the optical component, or a temperature-dependent current parameter, based on all preceding input laser pulses or output laser pulses that have contributed to the heating of the optical component, and
setting a power of a current input laser pulse based on the calculated current temperature, or the calculated current temperature difference, or the calculated current parameter, so that an associated output laser pulse has a pulse energy that deviates from a predefined pulse energy by less than 5%.

2. The method as claimed in claim 1 , wherein the input laser pulses are amplified or frequency-converted by the optical component.

3. The method as claimed in claim 1 , wherein the power of the current input laser pulse is set before passing through the optical component by trimming a pulse shape of the current input laser pulse.

4. The method as claimed in claim 1 , wherein as soon as the current input laser pulse is generated, the power of the input laser pulse is correspondingly set based on the calculated current temperature, or the calculated current temperature difference, or the calculated current parameter.

5. The method as claimed in claim 1 , further comprising amplifying the input laser pulses upstream of the optical component.

6. The method as claimed in claim 5 , wherein at least one input laser pulse is amplified as a sacrificial laser pulse and is coupled out of a path of amplified input laser pulses upstream of the optical component.

7. The method as claimed in claim 1 , wherein a plurality of adjacent input laser pulses pass through the optical component as a laser burst and emerge from the optical component as an output laser burst.

8. The method as claimed in claim 1 , wherein the input laser pulses are provided at times such that the output laser pulses arrive at an output at individually requested times.

9. The method as claimed in claim 1 , wherein individual laser pulses are selected from a pulse sequence of laser pulses having the known pulse energies and are provided as the input laser pulses.

10. The method as claimed in claim 1 , wherein laser pulses are generated with the known pulse energies and pulse spacings as the input laser pulses.

11. A laser system for generating output laser pulses from input laser pulses, the laser system comprising:
a pulse source for providing the input laser pulses having previously known pulse energies and pulse times,
an optical component with temperature-dependent power efficiency, wherein the input laser pulses pass through the optical component, the optical component is heated by the passing of the input laser pulses, and the input laser pulses emerge from the optical component as output laser pulses,
a power setting device for setting a respective pulse power of each of the input laser pulses, and
a control unit programmed to calculate a current temperature or a current temperature difference of the optical component, or a temperature-dependent parameter based on all preceding input laser pulses or output laser pulses that have contributed to the heating of the optical component, and to control the power setting device to set the respective pulse power of a current input laser pulse based on the calculated current temperature, or the calculated current temperature difference, or the calculated current parameter so that an associated output laser pulse has a pulse energy that deviates from a predefined pulse energy by less than 5%.

12. The laser system as claimed in claim 11 , wherein the optical component is an optical amplifier for amplifying the input laser pulses, or a conversion crystal for converting a frequency of the input laser pulses.

13. The laser system as claimed in claim 11 , wherein the power setting device is configured as an acousto-optic or electro-optic modulator for trimming a pulse shape of the current input laser pulse, or is formed by a power closed-loop control facility for the input laser pulses generated by the pulse source.

14. The laser system as claimed in claim 11 , further comprising an optical amplifier for amplifying the input laser pulses, the optical amplifier being arranged upstream of the optical component.

15. The laser system as claimed in claim 14 , further comprising a coupling-out unit controlled by the control unit, wherein the coupling-out unit comprises an acousto-optic or electro-optic modulator for coupling amplified input laser pulses as sacrificial laser pulses out of a path of the input laser pulses, and the coupling-out unit is disposed downstream of the amplifier and upstream of the optical component.

16. The laser system as claimed in claim 11 , wherein the pulse source comprises a laser pulse generator for generating laser pulses having the known pulse energies, and a selection unit for selecting some of the laser pulses as input laser pulses at the previously known pulse times, the selection unit being controlled by the control unit.

17. The laser system as claimed in claim 11 , wherein the pulse source comprises a laser pulse generator controlled by the control unit in order to generate the input laser pulses having the known pulse energies and pulse times.

18. A non-transitory computer-readable medium having program code stored thereon, the program code, when executed by a computer processor, causing performance of the method as claimed in claim 1 .

Assignees

• Trumpf Laser Gmbh

Inventors

• Brons Jonathan
• Flaig Rainer
• Sutter Dirk
• Zawischa Ivo

Classifications

• H01S3/0092 Primary

  Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35) · CPC title

• H01S3/0085

  Modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• H01S3/10015

  by monitoring or controlling, e.g. attenuating, the input signal · CPC title

• H01S3/1302

  by all-optical means, e.g. gain-clamping · CPC title

• G02F1/353

  Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams · CPC title