Optical chirped beam amplification and propagation

• US 6,804,045 B2
• Filed: 05/24/2002
• Issued: 10/12/2004
• Est. Priority Date: 05/24/2002
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Barty, Christopher P. J.
• Primary Examiner(s): Moskowitz, Nelson
• Assistant Examiner(s): Hughes, Deandra M.
• Application Number:
  US10/155,751
• Publication Number:
  US 20030218795A1
• Time in Patent Office: 872 Days
• Field of Search: 398/160, 359/337, 359/333
• US Class Current: 359/337
• 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 3/1675 titanate, germanate, molybdate, tungstate
• CPC Class Codes: H01S 3/2308 Amplifier arrangements, e.g. MOPA

Abstract

A short pulse laser system uses dispersive optics in a chirped-beam amplification architecture to produce high peak power pulses and high peak intensities without the potential for intensity dependent damage to downstream optical components after amplification.

Claims

1. An apparatus, comprising:

a source of one or more temporally chirped pulses,

at least one dispersive optic adapted to receive, frequency disperse and collimate a spectral content of said chirped pulses at predetermined local spatial coordinates to produce a chirped beam,

an amplifier constructed to receive and amplify said chirped beam; and

an optical means arranged to receive and optically compress in time and space said amplified chirped beam.

2. The apparatus of claim 1, wherein said dispersive optic comprises a first and a second reflective diffraction grating.

3. The apparatus of claim 2, wherein said first and said second grating further comprise a multilayer dielectric reflection diffraction grating.

4. The apparatus of claim 3, wherein said first reflective diffraction grating is adapted to disperse a spectral content of said chirped pulses and wherein said second reflective diffraction grating is adapted to receive said dispersed spectral content at a selected angle of incidence and a predetermined separation distance from said first reflective grating to produce one or more transform limited pulses of long temporal duration in a chirped beam at predetermined local spatial coordinates in one dimension, wherein a local spectral content is reduced by the ratio of an input beam width at said first reflective diffraction grating to a collimated beam width at said second diffraction grating to provide a spatial chirp ratio between about 2 and about 100.

5. The apparatus of claim 1, wherein said dispersive optic further comprises one or more reflective diffraction gratings adapted to disperse a spectral content of said chirped pulses and designed to receive said dispersed spectral content at a selected angle of incidence to produce one or more collimated, transform limited pulses of long temporal duration in a chirped beam in two dimensions, wherein said local spectral content is reduced by the ratio of an input beam area to an output beam area at said second reflective diffraction grating to provide a spatial chirp ratio between about 1000 and about 100,000.

6. The apparatus of claim 5, wherein a compressed pulse beam having a substantially annular frequency distribution with respect to the radius of said chirped beam is produced.

7. The apparatus of claim 5, wherein a compressed pulse beam having a substantially annular frequency distribution with respect to a position on said chirped beam is produced.

8. The apparatus of claim 1, wherein said dispersive optic comprises a first and a second transmission diffraction grating.

9. The apparatus of claim 8, wherein said first transmission diffraction grating is adapted to disperse a spectral content of said chirped pulses and wherein said second transmission diffraction grating is adapted to receive said dispersed spectral content at a selected angle of incidence and a predetermined separation distance from said first reflective grating to produce one or more transform limited pulses of long temporal duration in a chirped beam at predetermined local spatial coordinates in one dimension, wherein a local spectral content is reduced by the ratio of an input beam width at said first transmission diffraction grating to a beam width at said second transmission diffraction grating to provide a spatial chirp ratio between about 2 and about 100.

10. The apparatus of claim 1, wherein said dispersive optic further comprises one or more transmissive diffraction gratings adapted to disperse a spectral content of said chirped pulses and designed to receive said dispersed spectral content at a selected angle of incidence to produce one or more collimated, transform limited pulses of long temporal duration in a chirped beam in two dimensions, wherein a local spectral content is reduced by the ratio of an input beam area to an output beam area at one or more final collimating diffraction gratings to provide a spatial chirp ratio between about 1000 and about 100,000.

11. The apparatus of claim 10, wherein a compressed pulse beam having an annular frequency distribution with respect to the radius of said beam is produced.

12. The apparatus of claim 10, wherein a compressed pulse beam having an annular frequency distribution with respect to a position of said beam is produced.

13. The apparatus of claim 1, wherein said optical means for compressing further comprises a focusing optic to produce a short duration optical pulse.

14. The apparatus of claim 13, wherein said focusing optic produces a substantially tilted line focus having an intensity greater than 10¹² Watts.

15. The apparatus of claim 13, wherein said focusing optic is transmissive.

16. The apparatus of claim 15 wherein said focusing optic is an achromat capable of minimizing chromatic aberration.

17. The apparatus of claim 13, wherein said focusing optic is reflective.

18. The apparatus of claim 17, wherein said focusing optic is a parabolic reflector.

19. The apparatus of claim 1, wherein said source comprises a lasing material selected from Erbium, Neodymium(Nd)-doped glass, Neodymium-doped yttrium lithium fluoride, Yb:

YAG, Ti;

Sapphire, Yb;

glass, KGW, KYW, YLF, S-FAP, YALO, YCOB, Cr;

forsterite, and GdCOB.

20. The apparatus of claim 1, wherein said source comprises an excimer laser.

21. The apparatus of claim 1, wherein said amplifier comprises a lasing material selected from Neodymium(Nd)-doped glass, Neodymium-doped yttrium lithium fluoride, Yb:

YAG, Ti;

Sapphire, Yb;

glass, KGW, KYW, YLF, S-FAP, YALO, YCOB, Cr;

forsterite and GdCOB.

22. The apparatus of claim 1, wherein said dispersive optic is further adapted to receive amplified temporally chirped pulses from said amplifier with a predetermined bandwidth such that said amplified pulses having a spectral content are frequency dispersed and collimated locally in space.

23. An apparatus, comprising:

a source of one or more temporally chirped pulses,

at least one dispersive optic adapted to receive said chirped pulses, frequency disperse and collimate a spectral content of said chirped pulses at predetermined local spatial coordinates to produce a chirped beam, wherein an amplifier having a predetermined bandwidth is constructed to receive and amplify said chirped beam and wherein said dispersive optic is further adapted to receive amplified temporally chirped pulses from said amplifier and adapted to produce an amplified chirped beam; and

an optical means arranged to receive and optically compress said chirped beam in time and space.

24. An apparatus, comprising:

a source of temporally chirped pulses,

a first diffraction grating adapted to serially receive and to disperse to predetermined local spatial coordinates, a spectral content of said chirped pulses in one dimension,

a second diffraction grating adapted to serially receive and collimate said dispersed pulses from said first diffraction grating to produce a chirped beam, wherein a local spatial spectral content is reduced by the ratio of a predetermined input beam dimension at an input to said first diffraction grating to a designed beam dimension at an output of said second diffraction grating,

a Nd;

Glass amplifier, constructed to serially receive said collimated pulses from said second diffraction grating to produce amplified transform limited pulses; and

an optical means for focusing said amplified pulses received from said second diffraction grating, wherein said pulses overlap in space and time at a focus.

25. The apparatus of claim 24, wherein said optical means for compressing further comprises a focusing optic to produce a short duration optical pulse.

26. The apparatus of claim 25, wherein said focusing optic produces a substantially tilted line focus that rapidly varies in intensity and in pulse duration longitudinally in a predetermined confocal region having an intensity greater than 10¹² Watts at 10⁵³ nm.

27. The apparatus of claim 24, wherein said source comprises a lasing material selected from Erbium, Neodymium(Nd)-doped glass, Neodymium-doped yttrium lithium fluoride, Yb:

YAG, Ti;

Sapphire, Yb;

glass, KGW, KYW, YLF, S-FAP, YALO, YCOB, Cr;

forsterite, and GdCOB.

28. The apparatus of claim 24, wherein said source of laser pulses comprises an excimer laser.

29. A method of producing an ultra-high peak power pulse, comprising:

producing one or more temporally chirped pulses from a lasing source having a spectral content,

dispersing said spectral content of said chirped pulses in one dimension to predetermined local spatial coordinates,

collimating at said predetermined local spatial coordinates said locally dispersed spectral content to produce transform-limited pulses of long local temporal duration in a chirped beam having a chirp ratio between about 2 and about 100,

amplifying said transform limited pulses in a solid-state amplifying media; and

compressing in time and space said transform-limited pulses.

30. The method of claim 29, wherein said lasing source comprises a lasing material selected from Erbium, Neodymium(Nd)-doped glass, Neodymium-doped yttrium lithium fluoride, Yb:

YAG, Ti;

Sapphire, Yb;

glass, KGW, KYW, YLF, S-FAP, YALO, YCOB, Cr;

forsterite, and GdCOB.

31. The method of claim 29, wherein said lasing source further comprises an excimer laser.

32. The method of claim 29, wherein said amplifying media is a lasing material selected from Neodymium(Nd)-doped glass, Neodymium-doped yttrium lithium fluoride, Yb:

YAG, Ti;

Sapphire, Yb;

glass, KGW, KYW, YLF, S-FAP, YALO, YCOB, Cr;

forsterite, and GdCOB.

33. The method of claim 29, wherein said amplifying media further comprises an excimer laser.

34. The method of claim 29, wherein said compressed amplified pulses have a pulse duration from about 0.05 to less than about 10 picoseconds, a bandwidth between about 1.5 and about 70 nm, and wherein a compressed laser pulse has an intensity greater than 10¹² Watts, and a wavelength in the range from about 200 to about 2000 nm.

35. The method of claim 29, wherein each said compressed amplified pulse has an intensity greater than 10¹² Watts, and an operating wavelength of 1053 nm.

36. The method of claim 29, wherein said step of compressing further comprises an optical device focusing said amplified transform limited pulse to a substantially tilted line focus that rapidly varies in intensity and in pulse duration longitudinally in a predetermined confocal region, wherein a plasma mirror is adapted to receive said focusing pulse and produce a plasma to illuminate a target as said tilted line focus moves through said region.

37. The method of claim 36, wherein said plasma mirror is flat.

38. The method of claim 36, wherein said plasma mirror is curved.

39. The method of claim 29, wherein said step of dispersing further comprises the steps of dispersing said spectral content of said pulses in two dimensions to predetermined local spatial coordinates;

and collimating said dispersed pulses to produce one or more transform limited pulses each having a long local temporal duration in a chirped beam in two dimensions, wherein a local spectral content is reduced by the ratio of an input beam area to an output beam to provide a chirp ratio between about 1000 and about 100,000.

40. The method of claim 39, wherein said chirped beam has an annular frequency distribution with respect to the radius of said chirped beam to provide atmospheric propagation over large distances from about 1 meter to about hundreds of kilometers.

41. The method of claim 39, wherein said chirped beam has an annular frequency distribution with respect to a position of said chirped beam to provide atmospheric propagation over large distances from about 1 meter to about hundreds of kilometers.

43. The method of claim 41, wherein said dispersing step further comprises the steps of dispersing said spectral content of said pulses in two dimensions to predetermined local spatial coordinates;

and collimating said dispersed pulses to produce one or more transform limited pulses each having a long local temporal duration in a chirped beam in two dimensions, wherein a local spectral content is reduced by the ratio of an input beam area to an output beam area to provide a chirp ratio between about 1000 and about 100,000.

42. A method of producing an ultra-high peak power pulse, comprising:

producing one or more positive temporally chirped pulses from a lasing source having a spectral content,

amplifying said positive temporally chirped pulses in a solid-state amplifying media,

dispersing said amplified chirped pulses in one dimension to predetermined local spatial coordinates,

collimating said locally dispersed spectral content to produce one or more transform-limited pulses having a long local temporal duration in a chirped beam having a chirp ratio between about 2 and about 100; and

compressing in time and space said chirped beam.

44. A method comprising:

producing one or more pulses from a lasing source having a spectral content and a predetermined pulse width,

linearly chirping in time said spectral content to produce one or more temporally stretched pulses to be amplified,

amplifying said one or more temporally stretched pulses in an amplifying medium,

dispersing said amplified chirped pulses in one or more dimensions to predetermined local spatial coordinates,

collimating said locally dispersed spectral content to produce one or more transform-limited pulses having a long local temporal duration in a chirped beam; and

compressing in time and space said chirped beam.