Laser microscope with ablation function

Patent metadata

Field	Value
Publication number	US-11262312-B2
Application number	US-201716303558-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	May 20, 2016
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

An exemplary laser microscope can be provided, comprising at least one first laser source which emits at least one (e.g., pulsed) excitation beam, a scanning optical configuration (e.g., configured to scan the excitation beam over the surface of a sample), a focusing optical configuration (e.g., configured to focus the excitation beam onto the sample), and at least one detector configured to detect light emitted by the sample due to an optical effect in response to the excitation beam. A second laser source facilitates a pulsed ablation beam for a local ablation of the material of the sample. The ablation beam can be guided to the sample via the scanning and focusing optical configurations. The first and second laser sources can be fed by a mutual continuous wave pump laser and/or a mutual pulsed pump laser. The first laser source can emit pulses with at least two different wavelengths.

First claim

The invention claimed is:

1. A laser microscope, comprising:
at least one first laser source configured to emit at least one excitation beam having pulses;
an optical scanner configured to scan the at least one excitation beam over the surface of a sample;
focusing optics configured to focus the at least one excitation beam onto the sample;
at least one detector configured to detect light emitted from the sample due to an optical effect in response to the at least one excitation beam impacting the sample;
a second laser source configured to provide a pulsed ablation beam for a local ablation of a material of the sample; and
a spectral filter through which the at least one excitation beam is guided,
wherein the optical scanner and the focusing optics guide the ablation beam to the sample,
wherein the first and second laser sources are fed by at least one of a mutual continuous wave pump laser or a mutual pulsed pump laser,
wherein the first laser source emits the pulses with at least two different wavelengths, and
wherein a particular beam provided by the mutual continuous wave pump laser is guided into an optical oscillator, and further comprising a beam splitter configured to split a pulsed beam emitted by the optical oscillator in (i) the at least one excitation beam, and (ii) the ablation beam.

2. The laser microscope of claim 1 , wherein the first laser source emits the pulses with at least three different wavelengths.

3. The laser microscope of claim 1 , wherein the pulsed ablation beam provided by the second laser source has at least one wavelength that is congruent with at least one wavelength of the at least one excitation beam emitted by the first laser source.

4. The laser microscope of claim 1 , wherein the at least one excitation beam and the ablation beam have different wavelengths, and further comprising a dichromatic beam splitter merging the excitation and ablation beams.

5. The laser microscope of claim 1 , wherein polarization directions of the first laser source and the second laser source are provided at an angle between about 70 and 110 degrees.

6. The laser microscope of claim 5 , wherein the polarization directions are orthogonal to each other.

7. The laser microscope of claim 5 , further comprising a polarization maintaining beam splitter configured to merge the at least one excitation beam and the ablation beam.

8. The laser microscope of claim 1 , wherein a particular beam provided by the mutual continuous wave pump laser is guided into an optical oscillator, and further comprising a beam splitter configured to split a pulsed beam emitted by the optical oscillator in (i) the at least one excitation beam, and (ii) the ablation beam.

9. The laser microscope of claim 8 , further comprising a spectral filter through which the at least one excitation beam is guided.

10. The laser microscope of claim 1 , wherein the at least one detector is configured to detect the light formed from the at least one excitation beam by coherent Raman scattering.

11. The laser microscope of claim 10 , wherein the at least one detector is configured to detect the light formed from the at least one excitation beam by coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS).

12. The laser microscope of claim 1 , wherein a wavelength emitted by at least one of the first laser source or the second laser source is between about 750 nm and about 3 μm.

13. The laser microscope of claim 12 , wherein the wavelength emitted by at least one of the first laser source or the second laser source is between about 750 nm and about 2 μm.

14. The laser microscope of claim 13 , wherein the wavelength emitted by at least one of the first laser source or the second laser source is between about 750 nm and 1.5 μm.

15. The laser microscope of claim 14 , wherein the at least one detector is configured to be sensitive for the light that the sample emits due to a nonlinear optical effect in response of the at least one excitation beam impacting the sample.

16. A method for operating or providing a laser microscope, the laser microscope causing a pulsed excitation beam and a pulsed ablation beam to be guided to a sample, the method comprising:
scanning the pulsed excitation beam and the pulsed ablation beam over the sample, wherein the pulsed excitation beam is fed by at least one of a mutual continuous wave pump laser or a mutual pulsed pump laser, and wherein a particular beam provided by the mutual continuous wave pump laser is guided into an optical oscillator;
splitting, using a beam slitter, a pulsed beam emitted by the optical oscillator in (i) the pulsed excitation beam, and (ii) the pulsed ablation beam;
using at least one detector, detecting light emitted by the sample due to a nonlinear optical effect in response to the pulsed excitation beam impacting the sample; and
guiding the excitation beam through a spectral filter,
wherein the pulse duration of the pulsed ablation beam is selected to be between about 35 fs and about 300 fs.

17. The method of claim 16 , wherein a pulse duration of the excitation beam is selected to be longer by a factor between about 10 and 1000 than a pulse duration of the pulsed ablation beam.

18. The method of claim 16 , wherein a pulse duration of the pulse excitation beam is selected from a range between about 1 ps and about 100 ps.

19. The method of claim 18 , wherein the pulse duration of the pulse excitation beam is selected from a range between about 5 ps and about 40 ps.

20. The method of claim 19 , wherein the pulse duration of the pulse excitation beam is selected from a range between about 10 ps and about 20 ps.

21. The method of claim 16 , wherein a repetition rate of pulses of the pulsed excitation beam is selected between about 1 MHz and about 40 MHz.

22. The method of claim 21 , wherein the repetition rate of the pulses of the pulsed excitation beam is selected between about 1 MHz and about 20 MHz.

23. The method of claim 16 , wherein a repetition rate of pulses of the pulsed ablation beam is selected between about 100 kHz to about 10 MHz.

24. The method of claim 23 , wherein the repetition rate of the pulses of the pulsed ablation beam is selected between about 100 kHz and about 1 MHz.

25. The method of claim 16 , further comprising:
obtaining the image by scanning the excitation beam; and
analyzing the image as to whether the sample has a predetermined structure or a characteristic by applying at least one multivariant classifier.

26. The method of claim 25 , further comprising:
changing the image to a test image by a superimposition with noise; and
analyzing a reliability of the at least one multivariant classifier by comparing results provided by the at least one multivariant classifier when applied on the image and the test image.

27. The method of claim 16 , wherein the laser microscope comprises:
at least one first laser source configured to emit the pulsed excitation beam;
a optical scanner configured to scan the pulsed excitation beam over the surface of the sample;
focusing optics configured to focus the pulsed excitation beam onto the sample; and
a second laser source configured to provide the pulsed ablation beam for a local ablation of a material of the sample,
wherein the optical scanner and the focusing optics guide the ablation beam to the sample,
wherein the first and second laser s

Assignees

• Leibniz Inst Fuer Photonische
• Univ Jena Friedrich Schiller
• Leibniz Institut Fur Photonische Tech E V

Inventors

• Popp Jürgen
• Schmitt Michael
• Meyer-Zedler Tobias
• Nolte Stefan
• Ackermann Roland
• Limpert Jens

Classifications

• G01N21/6458 Primary

  Fluorescence microscopy (fluorescence microscopes per se G02B21/0076 and G02B21/16) · CPC title

• G01N2021/655

  Stimulated Raman · CPC title

• G01N21/718 Primary

  Laser microanalysis, i.e. with formation of sample plasma · CPC title

• G01N2021/656

  Raman microprobe · CPC title

• G01N21/65

  Raman scattering · CPC title