Reduction of pulse width by spectral broadening in amplification stage and after amplification stage

Abstract

This invention discloses a fiber Chirped Pulse Amplification (CPA) laser system. The system includes a fiber mode-locking oscillator for generating a seed laser. The laser system further includes a stretching stage for stretching the seed laser for projecting to an Yb doped amplifier. The Yb doped amplifier is implemented for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of the laser pulse is without narrowing down the spectrum. The amplifier has a gain spectrum corresponding to a broaden spectrum by taking advantage of the SPM in the amplifier. The amplifier is further connected to an output fiber having a predefined length with a predefined level of SPM for broadening a spectrum.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram for showing a fiber laser system with fiber of various lengths to carry out laser system tests.

FIG. 2 is a diagram for showing the pulse width versus pump-current with and without extra length of fiber at the output end.

FIG. 3 is a spectra diagram for various pump power of the laser system with extra fiber.

FIG. 4 is a diagram for showing the pulse width for various pump power for the laser system with extra fiber.

Claims

1. A fiber Chirped Pulse Amplification (CPA) laser system comprising: a fiber mode-locking oscillator for generating a laser for projecting to a doped amplifier implemented for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

2. The fiber CPA laser system of claim 1 wherein: said amplifier is implemented with a Yb doped fiber for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

3. The fiber CPA laser system of claim 1 wherein: said amplifier is implemented with a Er doped fiber for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

4. The fiber CPA laser system of claim 1 wherein: said amplifier is implemented with a Er/Yb co-doped fiber for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

5. The fiber CPA laser system of claim 1 wherein: said amplifier is implemented with a Tm doped fiber for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

6. The fiber CPA laser system of claim 1 wherein: said amplifier is implemented with a single mode, a multi-mode, a combination of two or more types, a single cladding, double cladding, or air cladding, or Photonic crystal fibers for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

7. The fiber CPA laser system of claim 1 wherein: said amplifier is further connected to an output fiber having a predefined length with a predefined level of SPM for broadening a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

8. The fiber CPA laser system of claim 1 further comprising: a stretching stage for stretching said seed laser before projecting to said amplifier.

9. The fiber CPA laser system of claim 1 wherein: said amplifier having a gain spectrum corresponding to a broaden spectrum by taking advantage of said SPM in said amplifier.

10. The fiber CPA laser system of claim 1 further comprising: an extra length of fiber after said amplifier whereby said spectrum of said laser is broadened without being limited by a gain spectrum of said amplifier

11. The fiber CPA laser system of claim 1 further comprising: an extra length of fiber after said amplifier whereby said spectrum of said laser is broadened without being limited by a gain spectrum of said amplifier wherein said extra length of fiber is optimized to have a particular length for a predefined peak power, a fiber structure.

12. The fiber CPA laser system of claim 1 further comprising: an extra length of fiber after said amplifier whereby said spectrum of said laser is broadened without being limited by a gain spectrum of said amplifier wherein said extra length of fiber is optimized to have a length of approximately two meters for a predefined peak power of 250 mW output power.

13. A fiber Chirped Pulse Amplification (CPA) laser system comprising: a fiber mode-locking oscillator for generating a seed laser;a stretching stage for stretching said seed laser for projecting to an Yb doped amplifier;said Yb doped amplifier implemented for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum;said amplifier having a gain spectrum corresponding to a broaden spectrum by taking advantage of said SPM in said amplifier; andsaid amplifier is further connected to an output fiber having a predefined length with a predefined level of SPM for broadening a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

14. A method of generating fiber laser comprising: generating a laser from a fiber oscillator; andprojecting said laser from said fiber oscillator to an amplifier comprising a doped fiber for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

15. The method of claim 14 wherein: said step of amplifying said laser through said amplifier is a step of amplifying said laser with a Yb doped fiber for taking advantage of said self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

16. The method of claim 14 wherein: said step of amplifying said laser through said amplifier is a step of amplifying said laser with a Er doped fiber for taking advantage of said self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

17. The method of claim 14 wherein: said step of amplifying said laser through said amplifier is a step of amplifying said laser with a Er/Yb co-doped fiber for taking advantage of said self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

18. The method of claim 14 wherein: said step of amplifying said laser through said amplifier is a step of amplifying said laser with a Tm doped fiber for taking advantage of said self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

19. The method of claim 14 wherein: said step of amplifying said laser through said amplifier is a step of amplifying said laser with a single mode, a multi-mode, a combination of two or more types, a single cladding, double cladding, or air cladding, or Photonic crystal fibers for taking advantage of a self phase modulation (SPM) to broaden a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

20. The method of claim 14 further comprising: projecting said laser from said amplifier to an output fiber having a predefined length with a predefined level of SPM for broadening a spectrum whereby an amplification of said laser pulse is without narrowing down said spectrum.

21. The method of claim 14 further comprising: receiving said seed laser into a stretching stage for stretching said seed laser before projecting to said amplifier.

22. The method of claim 14 wherein: said step of amplifying said laser through said amplifier further comprising a step of amplifying said laser through said amplifier having a gain spectrum corresponding to a broaden spectrum in taking advantage of said SPM in said amplifier.

23. The method of claim 14 further comprising: adding an extra length of fiber after said amplifier for further broadening said spectrum of said laser whereby said spectrum of said laser is broadened without being limited by a gain spectrum of said amplifier.