All-fiber chirped pulse amplification systems

• US 20050105865A1
• Filed: 11/22/2004
• Published: 05/19/2005
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: IMRA America Incorporated (Aisin Corp.)
• Original Assignee: IMRA America Incorporated (Aisin Corp.)
• Inventors: Harter, Donald J., Cho, Gyu C., Fermann, Martin E., Imeshev, Gennady, Liu, Zhenlin
• Granted Patent: US 7,414,780 B2
• Time in Patent Office: Days
• US Class Current: 385/122
• CPC Class Codes: H01S 3/0057 Temporal shaping, e.g. pulse compression, frequency chirping soliton generation and propagation G02F1/3513, H01S3/063 and H01S3/108
• CPC Class Codes: H01S 3/0064 Anti-reflection devices, e.g. optical isolaters absorbing layers for marking or protecting purposes in laser working B23K26/50; magneto-optical non-reciprocal devices G02F1/093, G02F1/0955
• CPC Class Codes: H01S 3/0078 Frequency filtering
• CPC Class Codes: H01S 3/06712 Polarising fibre; Polariser
• CPC Class Codes: H01S 3/06725 Fibre characterized by a specific dispersion, e.g. for pulse shaping in soliton lasers or for dispersion compensating [DCF]
• CPC Class Codes: H01S 3/06741 Photonic crystal fibre, i.e. the fibre having a photonic bandgap
• CPC Class Codes: H01S 3/06754 Fibre amplifiers H01S3/06708 takes precedence
• CPC Class Codes: H01S 3/06758 Tandem amplifiers
• CPC Class Codes: H01S 3/094007 Cladding pumping, i.e. pump light propagating in a clad surrounding the active core
• CPC Class Codes: H01S 3/1086 using scattering effects, e.g. Raman or Brillouin effect
• CPC Class Codes: H01S 3/1608 erbium
• CPC Class Codes: H01S 3/1618 ytterbium
• CPC Class Codes: H01S 3/2308 Amplifier arrangements, e.g. MOPA
• CPC Class Codes: H01S 3/2316 Cascaded amplifiers
• CPC Class Codes: H01S 3/302 in an optical fibre

Abstract

By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.

Claims

1. A fiber chirped pulse amplification system, comprising;

a seed source;

a pulse stretcher for temporally stretching pulses from said seed source;

a non-linear amplifier configured as a cubicon pulse amplifier; and

a pulse compressor;

wherein

said stretched pulses amplified in said amplifier are subjected to a substantial level of self-phase modulation, and

said substantial level of self-phase modulation provides a level of third-order dispersion that is at least partially compensated by the level of third-order dispersion from said pulse stretcher and said pulse compressor.

23. A system as described in claim 1, where the seed source is a bulk solid-state mode-locked laser.

24. A system as described in claim 1, where the seed source is a fiber mode-locked laser.

2. A fiber chirped pulse amplification system for sub-50 picosecond pulses, comprising:

a short pulse seed source providing sub-10 picosecond pulses;

a pulse stretcher configured to temporally stretch the pulses from said seed source to a width that is at least 10 times greater;

at least one non-linear fiber amplifier configured to accept pulses with an input pulse spectrum and emitting amplified pulses with a certain output pulse spectrum, said input pulse spectrum being derived from said seed pulse source, but not necessarily identical to said seed pulse source;

a pulse compressor having a level of second, third- and higher-order chromatic dispersion,

wherein said fiber amplifier is configured such that said output pulse spectrum is wavelength-shifted with respect to said input pulse spectrum, and

said fiber amplifier at least partially compensating for the third order dispersion of said pulse stretcher and compressor by self-phase modulation.

3. The amplification system for optical pulses according to claim 2, wherein said at least one amplifier is configured as a cubicon pulse amplifier.

4. A fiber chirped pulse amplification system for sub-50 picosecond pulses, comprising:

a short pulse seed source providing sub-10 picosecond pulses;

a pulse stretcher configured to temporally stretch the pulses from said seed source by a factor of 10 or more;

at least one nonlinear fiber amplifier configured such that an output pulse spectrum is wavelength-shifted with respect to an input pulse spectrum thereof; and

a pulse compressor;

wherein said fiber amplifier is further configured to at least partially compensate for third order dispersion of said pulse stretcher and compressor by self phase modulation.

5. A fiber chirped pulse amplification system for sub-50 picosecond pulses, comprising:

a short pulse seed source providing sub-10 picosecond pulses;

a pulse stretcher configured to temporally stretch the pulses from said seed source by a factor of at least 10;

at least one fiber amplifier configured to accept said stretched pulses and outputting amplified cubicon pulses;

a pulse compressor having a level of second, third- and higher-order chromatic dispersion;

wherein

said fiber amplifier is configured such that said cubicon pulses produce a nonlinear pulse chirp that is at least partially compensated by the level of third-order dispersion from said pulse stretcher and said pulse compressor.

6. The fiber chirped pulse amplification system according to claim 5, wherein said level of self-phase modulation is in the range of 0.3

7. A fiber chirped pulse amplification system, comprising;

a seed source;

a pulse stretcher for temporally stretching pulses from said seed source;

a non-linear amplifier configured as a cubicon pulse amplifier; and

a pulse compressor;

wherein

the pulses amplified in said amplifier are subjected to a substantial level of self-phase modulation, and such that there is an observable increase in amplitude modulation of an output spectrum of said pulses as compared to an input spectrum thereof.

8. A fiber chirped pulse amplification system for sub-50 picosecond pulses, comprising;

a short pulse seed source providing sub-10 picosecond pulses;

a pulse stretcher configured to temporally stretch the pulses from said seed source to a width of more than 10 picoseconds;

at least one fiber amplifier configured to accept pulses with an input pulse spectrum and emitting amplified pulses with a certain output pulse spectrum, said input pulse spectrum being derived from said seed pulse source, but not necessarily identical to said seed pulse source,

a pulse compressor having a level of second, third- and higher-order chromatic dispersion,

wherein said fiber amplifier is configured such that said output pulse spectrum is substantially gain narrowed with respect to said input pulse spectrum, and

said fiber amplifier being further configured to at least partially compensate for the third order dispersion of said pulse stretcher and compressor.

9. The fiber chirped pulse amplification system according to claim 8, wherein

said stretched pulses amplified in said amplifier are subjected to a substantial level of self-phase modulation, and

said substantial level of self-phase modulation provides a level of third-order dispersion which at least partially compensates for the level of third-order dispersion from said pulse stretcher and pulse compressor.

10. The fiber chirped pulse amplification system according to claim 9, wherein said level of self-phase modulation is in the range of 0.3-10%.

11. The fiber chirped pulse amplification system according to claim 9, wherein said level of self-phase modulation is manifested in an increase in amplitude modulation of the output pulse spectrum compared to the input pulse spectrum.

12. A method for the generation of high quality pulses from a fiber chirped pulse amplification system in the presence of self-phase modulation in the fiber amplifier, comprising:

selecting stretched pulses with an input pulse spectrum into the fiber amplifier such that substantial gain-pulling occurs in said amplifier,

said gain-pulling manifesting itself in a substantial spectral shift of the average optical frequency of the pulse spectrum,

wherein the quality of the compressed pulses improves in the presence of self-phase modulation.

13. A method for the generation of high quality pulses from a fiber chirped pulse amplification system in the presence of self-phase modulation in the fiber amplifier, comprising:

selecting stretched pulses with an input pulse spectrum into the fiber amplifier such that substantial gain-narrowing occurs in said amplifier,

said gain-narrowing manifesting itself in the generation of an amplified pulse spectrum with a spectral width not greater than the input pulse spectrum,

wherein the quality of the compressed pulses improves in the presence of self-phase modulation.

14. A method for the generation of high quality pulses from a fiber chirped pulse amplification system in the presence of self-phase modulation in the fiber amplifier, comprising:

selecting stretched pulses with an input pulse spectrum into the fiber amplifier such that substantial gain-pulling as well as gain-narrowing occurs in said amplifier,

said gain-pulling manifesting itself in a substantial spectral shift of the average optical frequency of the pulse spectrum,

said gain-narrowing manifesting itself in the generation of an amplified pulse spectrum with a spectral width not greater than the input pulse spectrum,

wherein the quality of the compressed pulses improves in the presence of self-phase modulation.

15. A method for improving the output pulse quality in high power waveguide chirped pulse amplification systems, wherein the output pulse quality improves with an increase in pulse energy, wherein said increase in pulse energy further leads to a 0.3-10π

level of self-phase modulation in said waveguide chirped pulse amplification system.

16. A method for improving the output pulse quality in high power waveguide chirped pulse amplification systems, in the presence of self-phase modulation in the fiber amplifier, comprising:

selecting stretched pulses with an input pulse spectrum into said fiber amplifier,

said input pulse spectrum being conditioned by a seed source and an optical filter inserted between said seed source and said fiber amplifier,

further selecting the optical bandwidth and center wavelength of said seed source as well as the transmission bandwidth and the center wavelength of said filter such that the quality of the compressed pulses improves in the presence of self-phase modulation.

17. A fiber chirped pulse amplification system, comprising:

a short pulse seed source;

a pulse stretcher configured to temporally stretch the pulses from said seed source;

at least one fiber amplifier configured as a cubicon pulse amplifier, and

a pulse compressor having a level of third order dispersion partially corrected by self phase modulation within said fiber amplifier.

18. A fiber chirped pulse amplification system, comprising:

a short pulse optical source;

a pulse stretcher configured to temporally stretch the pulses from said source;

at least one nonlinear fiber amplifier configured to accept pulses with an input pulse spectrum and emitting amplified pulses with a shifted output pulse spectrum;

a pulse compressor having a level of third-order chromatic dispersion,

said nonlinear fiber amplifier being of a type which at least partially compensates for the third order dispersion of at least said compressor, and being operable in a large self-phase modulation regime of 0.3-10π

.

19. A fiber chirped pulse amplification system as claimed in claim 18, wherein the nonlinear amplifier is a nonlinear undoped fiber and a linear amplifier.

20. A fiber chirped pulse amplification system, comprising:

a short pulse optical source system capable of producing stretched optical pulses;

a power amplifier receiving said stretched pulses at an input thereof;

and being operable in a large self-phase modulation regime, and producing a pulse output which improves in pulse quality with increasing amplitude ripple in an output spectrum thereof.

21. A fiber chirped pulse amplification system, comprising:

a short pulse optical source system capable of producing stretched optical pulses;

a power amplifier receiving said stretched pulses at an input thereof; and

being operable in a large self-phase modulation regime, and producing a pulse output which improves in pulse quality, and whose higher order dispersion varies, with the pulse energy in the system.

22. A fiber-based higher order dispersion control system, comprising;

an optical pulse source module producing stretched pulses with a given amount of higher order dispersion;

a non-linear cubicon pulse amplifier which subjects said pulses to self phase modulation during amplification, said self-phase modulation providing a level of third-order dispersion; and

a pulse compressor having a given amount of higher order dispersion;

wherein through asymmetric pulse amplitude shaping followed by said self-phase-modulation in said amplifier, dispersion of an output may be controlled.