Supercontinuum light source

Patent metadata

Field	Value
Publication number	US-10441158-B2
Application number	US-201815980177-A
Country	US
Kind code	B2
Filing date	May 15, 2018
Priority date	Jun 1, 2012
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A supercontinuum light source can include a seed laser arranged to provide seed pulses with a pulse frequency Fseed; a pulse frequency multiplier (PFM) arranged to multiply the seed pulses by converting pulses having the pulse frequency Fseed to pump pulses with a pulse frequency Fpump, where Fpump is larger than Fseed; and a non-linear element arranged to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light. The PFM can further include a splitter for splitting pulses into first and second sub beams each having the same pulse frequency, where the PFM is configured such that the sub beams experience different delays; and a combiner for combining said first and second sub beams into a beam having the pulse frequency that is greater than said same pulse frequency. The splitter can have an uneven splitter ratio. The disclosure includes other embodiments as well.

First claim

The invention claimed is:

1. A supercontinuum light source comprising:
a seed laser configured to provide seed pulses with a pulse frequency F seed ;
a pulse frequency multiplier (PFM) configured to multiply the seed pulses by converting seed pulses having the pulse frequency F seed to pump pulses with a pulse frequency F pump , where F pump is larger than F seed ;
a non-linear element configured to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light; and
first and second amplifiers, one of the amplifiers configured to amplify pulses having the pulse frequency F seed and the other of the amplifiers configured to amplify pulses having the pulse frequency F pump ;
wherein said PFM is located between the amplifiers; and
wherein said PFM comprises a splitter configured to split seed pulses into first and second sub beams, wherein the splitter has an uneven split ratio.

2. The supercontinuum light source of claim 1 , wherein said PFM comprises an attenuator configured to attenuate pulses of light having a pulse frequency that is less than F pump .

3. The supercontinuum light source of claim 1 , wherein said PFM comprises a second splitter, said second splitter has a splitter ratio that is uneven.

4. The supercontinuum light source of claim 1 , wherein said PFM comprises a delay line for delaying one of the first and second sub beams.

5. The supercontinuum light source of claim 1 , wherein said PFM comprises an attenuator for attenuating one of the first and second sub beams.

6. The supercontinuum source of claim 1 , wherein said non-linear element comprises a microstructured optical fiber.

7. The supercontinuum source of claim 1 , wherein F pump is 150 MHz or more.

8. The supercontinuum light source of claim 1 , wherein said seed laser is configured to provide seed pulses with a pulse duration t seed that is longer than about 1 ps.

9. The supercontinuum light source of claim 8 , wherein t seed is shorter than about 50 ps.

10. The supercontinuum light source of claim 1 , wherein the supercontinuum light source is configured such that the total average optical power in the range 400 nm-850 nm is less than 100 mW.

11. The supercontinuum light source of claim 1 , wherein the amplifiers provide an increase in pulse energy and peak power relative to an output from the seed laser.

12. The supercontinuum light source of claim 1 , wherein the supercontinuum light source is configured such that peak power of the pulses out of the first amplifier is constant.

13. The supercontinuum light source of claim 1 , wherein the supercontinuum light source is configured such that peak power of the pulses out of the second amplifier is constant.

14. The supercontinuum light source of claim 1 , wherein said seed laser comprises a mode locked Yb laser.

15. The supercontinuum light source of claim 14 , wherein said mode locked Yb laser comprises a fiber laser that is passively mode locked via a SESAM (Semiconductor Saturable Absorber Mirror).

16. A supercontinuum light source comprising:
a seed laser configured to provide seed pulses with a pulse frequency F seed ;
a pulse frequency multiplier (PFM) configured to multiply the seed pulses by converting seed pulses having the pulse frequency F seed to pump pulses with a pulse frequency F pump , where F pump is larger than F seed ;
a non-linear element configured to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light; and
first and second amplifiers, one of the amplifiers configured to amplify pulses having the pulse frequency F seed and the other of the amplifiers configured to amplify pulses having the pulse frequency F pump ;
wherein said PFM is located between the amplifiers; and
wherein the supercontinuum light source is configured such that the pulses of supercontinuum light have a pulse duration and wherein an average optical power output from the supercontinuum light source is less than 5 Watt output per ps pulse duration.

17. The supercontinuum light source of claim 16 , wherein said PFM comprises an attenuator configured to attenuate pulses of light having a pulse frequency that is less than F pump .

18. The supercontinuum light source of claim 16 , wherein said PFM comprises a splitter configured to split seed pulses into first and second sub beams, wherein the splitter has an uneven split ratio.

19. The supercontinuum light source of claim 16 , wherein said PFM comprises a second splitter, said second splitter has a splitter ratio that is uneven.

20. The supercontinuum light source of claim 16 , wherein said PFM comprises a delay line for delaying one of the first and second sub beams.

21. The supercontinuum light source of claim 16 , wherein said PFM comprises an attenuator for attenuating one of the first and second sub beams.

22. The supercontinuum light source of claim 16 , wherein said non-linear element comprises a microstructured optical fiber.

23. The supercontinuum light source of claim 16 , wherein F pump is 150 MHz or more.

24. The supercontinuum light source of claim 16 , wherein said seed laser is configured to provide seed pulses with a pulse duration t seed that is longer than about 1 ps.

25. The supercontinuum light source of claim 24 , wherein t seed is shorter than about 50 ps.

26. The supercontinuum light source of claim 16 , wherein the supercontinuum light source is configured such that the total average optical power in the range 400 nm-850 nm is less than 100 mW.

27. The supercontinuum light source of claim 16 , wherein the amplifiers provide an increase in pulse energy and peak power relative to an output from the seed laser.

28. The supercontinuum light source of claim 16 , wherein the supercontinuum light source is configured such that peak power of the pulses out of the first amplifier is constant.

29. The supercontinuum light source of claim 16 , wherein the supercontinuum light source is configured such that peak power of the pulses out of the second amplifier is constant.

30. The supercontinuum light source of claim 16 , wherein said seed laser comprises a mode locked Yb laser.

31. The supercontinuum light source of claim 30 , wherein said mode locked Yb laser comprises a fiber laser that is passively mode locked via a SESAM (Semiconductor Saturable Absorber Mirror).

Assignees

• Nkt Photonics As

Inventors

• Thomsen Carsten L
• Andersen Thomas Vestergaard
• Feuchter Thomas

Classifications

• G02F1/365

  in an optical waveguide structure (G02F1/377, {G02F1/395} take precedence) · CPC title

• G02B27/0927

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• G02F1/35 Primary

  Non-linear optics · CPC title

• G02F1/3501

  Constructional details or arrangements of non-linear optical devices, e.g. shape of non-linear crystals · 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