Hollow-core fiber based broadband radiation generator with extended fiber lifetime

Patent metadata

Field	Value
Publication number	US-12399313-B2
Application number	US-202318213085-A
Country	US
Kind code	B2
Filing date	Jun 22, 2023
Priority date	Jul 8, 2020
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

An optical component for a broadband radiation source device, the optical component configured for generating a broadband output upon receiving pump radiation and including: a hollow-core photonic crystal fiber (HC-PCF); and a gas mixture filling the HC-PCF, wherein the gas mixture includes a mixture of at least one first gas configured for the generation of the broadband radiation and at least one second gas including or consisting of helium.

First claim

The invention claimed is:

1. A source device configured to generate a broadband radiation output upon receipt of pump radiation, the broadband radiation source comprising:
an optical component, comprising:
a hollow-core photonic crystal fiber (HC-PCF), and
a gas mixture filling the HC-PCF, wherein the gas mixture comprises a mixture of at least one first gas configured for the generation of broadband radiation and at least one second gas; and

a pump radiation source configured to generate the pump radiation,
wherein an acoustic damping frequency of the gas mixture is substantially matched to a repetition rate of the pump radiation generated by the pump radiation source, the acoustic damping frequency corresponding to a frequency at a peak of an amplitude damping versus radiation frequency curve for the gas mixture.

2. The source device according to claim 1 , wherein the gas composition of the gas mixture is configured to match the acoustic damping frequency of the gas mixture to the repetition rate of the pump radiation.

3. The source device according to claim 1 , configured to tune the repetition rate of the pump radiation to match the acoustic damping frequency of the gas mixture.

4. The source device according to claim 1 , wherein the pump radiation source is configured such that the repetition rate of the pump radiation is unmatched with any acoustic resonance frequencies of an inner cladding structure of the HC-PCF.

5. The source device according to claim 1 , wherein an inner cladding structure of the HC-PCF comprises one or more silica tubes.

6. The source device according to claim 1 , wherein the gas mixture is configured to define a spectral range of the generated broadband radiation.

7. The source device according to claim 1 , wherein the broadband output comprises a wavelength range of 200 nm to 3000 nm, or a sub-range within this range.

8. A metrology device comprising the source device according to claim 1 .

9. The metrology device according to claim 8 , comprising a scatterometer metrology apparatus, a level sensor or an alignment sensor.

10. A method for configuring a source arrangement configured to generate a broadband radiation output and comprising a pump radiation source configured to output pump radiation, a hollow-core photonic crystal fiber (HC-PCF), and a gas medium filling the HC-PCF, the method comprising substantially matching an acoustic damping frequency of the gas medium to a repetition rate of the pump radiation generated by the pump radiation source, the acoustic damping frequency corresponding to a frequency at a peak of an amplitude damping versus radiation frequency curve for the gas mixture.

11. The method according to claim 10 , further comprising configuring a gas composition of the gas medium to match the acoustic damping frequency of the gas medium to the repetition rate of the pump radiation.

12. The method according to claim 10 , further comprising tuning the repetition rate of the pump radiation to match the acoustic damping frequency of the gas medium.

13. The method according to claim 10 , further comprising selecting the repetition rate of the pump radiation such that it is unmatched to any acoustic resonance frequencies of an inner cladding structure of the HC-PCF.

14. The method according to claim 10 , wherein the gas medium comprises a gas mixture of at least one first gas and at least one second gas, wherein the at least one first gas is configured for the generation of broadband radiation and the at least one second gas is configured to improve thermal conductivity of the gas mixture and/or provide acoustic damping of shock waves initiated during the generation of broadband radiation.

15. The method according to claim 14 , wherein the at least one second gas comprises an atomic gas.

16. The method according to claim 15 , wherein the at least one second gas comprises helium.

17. The method according to claim 15 , wherein the at least one first gas comprises an atomic gas having a greater atomic weight than the at least one second gas.

18. The method according to claim 17 , wherein the at least one first atomic gas is selected from: krypton, xenon, argon, neon.

19. A method for configuring a source arrangement configured to generate a broadband radiation output and comprising a pump radiation source configured to output pump radiation, a hollow-core photonic crystal fiber (HC-PCF), and a gas medium filling the HC-PCF, the method comprising selecting the repetition rate of the pump radiation such that it is unmatched to any acoustic resonance frequencies of an inner cladding structure of the HC-PCF.

20. The method according to claim 19 , wherein the gas medium comprises a gas mixture of at least one first gas and at least one second gas, wherein the at least one first gas is configured for the generation of broadband radiation and the at least one second gas is configured to improve thermal conductivity of the gas mixture and/or provide acoustic damping of shock waves initiated during the generation of broadband radiation.

Assignees

• Asml Netherlands Bv
• Asml Netherlands

Inventors

• Abdolvand Amir
• Craus Cristian Bogdan
• Ezerskaia Anna
• Domalapally Phani Kumar

Classifications

• G03F7/706849

  Irradiation branch, e.g. optical system details, illumination mode or polarisation control · CPC title

• G02F1/355 Primary

  characterised by the materials used · CPC title

• G02F1/383 Primary

  of the optical fibre type · CPC title

• G02F1/3528 Primary

  for producing a supercontinuum · CPC title

• G02B2006/0325

  Fluid core or cladding · CPC title