Supercontinuum light source

Patent metadata

Field	Value
Publication number	US-9766530-B2
Application number	US-201514956578-A
Country	US
Kind code	B2
Filing date	Dec 2, 2015
Priority date	Jul 11, 2008
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

A supercontinuum light source includes a microstructured optical fiber, and a feeding unit arranged for feeding pump pulses to the microstructured optical fiber, wherein the feeding unit comprises a picosecond laser and one or more amplifiers, wherein the microstructured optical fiber is a silica fiber wherein at least a part of the core being of silica or doped silica, and including a core including core material and a cladding surrounding the core, and at least the core material is loaded with deuterium to have an OD absorption peak around 1870 nm, wherein the feeding unit is spliced to the microstructured optical fiber.

First claim

The invention claimed is:

1. A supercontinuum light source comprising a microstructured optical fiber, and a feeding unit arranged for feeding pump pulses to said microstructured optical fiber,
wherein said feeding unit comprises a picosecond laser and one or more amplifiers,
wherein said microstructured optical fiber is a silica fiber having a core comprising a core material,
wherein at least a part of the core being of silica or doped silica, and
said microstructured optical fiber further comprising a cladding surrounding the core, and
at least said core material is loaded with deuterium to have an OD absorption peak around 1870 nm,
wherein said feeding unit is spliced to said microstructured optical fiber.

2. The supercontinuum light source of claim 1 , wherein said pump pulses have a duration of 8 ps or more.

3. The supercontinuum light source of claim 1 , wherein said supercontinuum light source is adapted to provide an optical output spanning over at least one octave with at least 10 micro W/nm.

4. The supercontinuum light source of claim 1 , wherein said supercontinuum light source has an increased spectral stability over time relative to a supercontinuum light source with an optical fiber without said OD absorption peak around 1870 nm.

5. The supercontinuum light source of claim 1 , wherein said microstructured optical fiber of said supercontinuum light source has a lifetime of more than 2000 operating hours.

6. The supercontinuum light source of claim 1 , wherein said feeding unit is adapted to feed said fiber with light with a peak power density within said fiber equal to or higher than 100 W/μm2.

7. The supercontinuum light source of claim 1 , wherein said pump pulses have a pump energy at least about 0.05 μJ.

8. The supercontinuum light source of claim 1 , wherein said OD absorption peak corresponds to a deuterium loading of said deuterium loaded material of 0.1 atom percent (at percent) bound deuterium or more.

9. An apparatus comprising a supercontinuum light source of claim 1 , the apparatus being at least one of a spectroscope, fluorescent microscope, an optical coherence tomography apparatus, a wafer overlay alignment apparatus or a wafer inspection apparatus.

10. An illumination source for surgical illumination comprising the supercontinuum light source of claim 1 .

11. A supercontinuum light source comprising a microstructured optical fiber, and a feeding unit arranged for feeding pump pulses to said microstructured optical fiber,
wherein said microstructured optical fiber comprises a core comprising core material and a cladding surrounding the core,
wherein at least said core material is loaded with deuterium to have an OD absorption peak around 1870 nm, and
wherein said feeding unit comprises a pump light source and said pump pulses have a pulse energy of at least 0.05 μJ and comprise a pump wavelength within ±200 nm of a zero dispersion wavelength of said microstructured optical fiber.

12. The supercontinuum light source of claim 11 , wherein said pump pulses have a pulse length of at least about 5 ps.

13. The supercontinuum light source of claim 11 , wherein said supercontinuum light source is adapted for generating a supercontinuum light comprising wavelengths above 2000 nm and wavelengths below 450 nm.

14. The supercontinuum light source of claim 11 , wherein said pulse feeding unit is configured for generating pulses with a selectable repetition rate.

15. The supercontinuum light source of claim 11 , wherein said pulse feeding unit is configured for generating pulses with a repetition rate comprising about 20 KHz or higher.

16. The supercontinuum light source of claim 11 , wherein said feeding unit is arranged for feeding pump pulses to a feeding end of said deuterium loaded microstructured optical fiber, said OD absorption peak is at least about 0.5 dB/m determined in a first meter of the feeding end of said deuterium loaded microstructured optical fiber.

17. The supercontinuum light source of claim 11 , wherein said pump pulses have a peak power of at least 5 kW and a pulse duration which is sufficiently large to ensure generation of wavelengths in the microstructured optical fiber above 2200 nm.

18. The supercontinuum light source of claim 11 , wherein said pump pulses comprise a plurality of wavelengths.

19. The supercontinuum light source of claim 11 , wherein said feeding unit comprises a seed laser and a chain of amplifiers comprising two or more amplifiers, and wherein said chain of amplifiers is configured for spectrally broadening seed pulses from said seed laser.

20. The supercontinuum light source of claim 19 , wherein said chain of amplifiers is configured for broadening seed pulses by a nonlinear effect comprising at least one of self-phase modulation and stimulated Raman scattering.

21. The supercontinuum light source of claim 19 , wherein said chain of amplifiers is configured for broadening seed pulses by a nonlinear effect comprising at least stimulated Raman scattering generating at least one Raman peak, wherein the at least one Raman peak preferably has an energy fraction of the pulse energy which is at least about 20%.

22. The supercontinuum light source of claim 11 , wherein said feeding unit comprises a mode locked fiber laser comprising a chirped FBG.

23. The supercontinuum light source of claim 11 , wherein said microstructured optical fiber has group velocity match between a wavelength larger than 2000 nm and a wavelength shorter than 500 nm.

24. The supercontinuum light source of claim 11 , wherein said microstructured optical fiber comprises a first and a second section differing from each other or wherein said microstructured optical fiber comprises a tapered section.

Assignees

• Nkt Photonics As

Inventors

• Thomsen Carsten L
• Andersen Thomas Vestergaard

Classifications

• H01S3/302

  in an optical fibre · CPC title

• G02B6/02319

  characterised by core or core-cladding interface features · CPC title

• G02B6/4296

  coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources · CPC title

• G02B6/02333

  Core having higher refractive index than cladding, e.g. solid core, effective index guiding · CPC title

• G02B6/02342

  characterised by cladding features, i.e. light confining region · CPC title