Laser Pulse Shaping System

• US 20090122819A1
• Filed: 11/04/2008
• Published: 05/14/2009
• Est. Priority Date: 01/30/2001
• Status: Active Grant

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Lozovoy, Vadim V., Dantus, Marcos
• Granted Patent: US 8,208,504 B2
• Time in Patent Office: Days
• US Class Current: 372/25
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0073 by tomography, i.e. reconstruction of 3D images from 2D projections A61B5/0066 takes precedence
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent
• CPC Class Codes: G01B 9/02014 by using pulsed light
• CPC Class Codes: G01B 9/02044 Imaging in the frequency domain, e.g. by using a spectrometer
• CPC Class Codes: G01B 9/02091 Tomographic interferometers, e.g. based on optical coherence
• CPC Class Codes: G01N 21/6402 Atomic fluorescence; Laser induced fluorescence
• 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

Abstract

A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and a spectrometer. Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal. In yet another aspect of the present invention, a multiphoton intrapulse interference phase scan system and method characterize the spectral phase of femtosecond laser pulses. Fiber optic communication systems, photodynamic therapy and pulse characterization tests use the laser system with additional aspects of the present invention.

Claims

1. A laser beam pulse shaping system comprising:

a laser beam pulse; and

a permanently fixed pulse shaper including multiple repeating and predetermined shaping patterns;

the fixed pulse shaper operably changing a phase characteristic of the pulse without computer control of the shaper.

2. The pulse shaping system of claim 1, further comprising a communications device operably receiving the pulse shaped by the fixed pulse shaper.

3. The pulse shaping system of claim 2, wherein the shaper encodes a communications signal onto the pulse for use by the communications device.

4. The pulse shaping system of claim 1, further comprising a two-dimensional CCD camera operably collecting and detecting the spectrum of a nonlinear optical signal, and retrieving information from the shaped pulse.

5. The pulse shaping system of claim 1, wherein the patterns are offset as a function of a wave phase.

6. The pulse shaping system of claim 1, wherein the substrate is polymeric.

7. The pulse shaping system of claim 1, wherein the substrate and wave patterns are of an injection molded material.

8. The pulse shaping system of claim 1, wherein the wave pattern is a sine wave which repeats across the substrate with adjacent rows of the pattern being offset from each other.

9. The pulse shaping system of claim 1, wherein the patterns operably generate multiple phases from a single laser beam pulse.

10. The pulse shaping system of claim 1, wherein the pattern is configured for a laser beam pulse of less than about 11 femtosecond duration.

11. The pulse shaping system of claim 1, wherein the fixed pulse shaper introduces multiphoton intrapulse interference in the pulse without computer control of the pulse shaper.

12. The pulse shaping system of claim 1, further comprising using the fixed pulse shaper to determine and characterize the phase of the pulse.

13. The pulse shaping system of claim 1, further comprising using the fixed pulse shaper to characterize the dispersion of a communications optical fiber.

14. A laser beam pulse shaper comprising a substrate and permanently fixed wave patterns located on the substrate, at least some of the wave patterns being offset from each other.

15. The pulse shaper of claim 14, wherein the patterns are offset as a function of the wave phase.

16. The pulse shaper of claim 14, wherein the substrate is polymeric.

17. The pulse shaper of claim 14, wherein the substrate and wave patterns are created by injection molding.

18. The pulse shaper of claim 14, wherein each of the wave patterns is a sine wave which repeats across the substrate with adjacent rows of the pattern being offset from each other.

19. The pulse shaper of claim 14, wherein the wave patterns operably generate multiple phases from a single laser beam pulse.

20. The pulse shaper of claim 14, wherein the wave patterns are configured for a laser beam pulse of less than about 11 femtosecond duration.

21. The pulse shaper of claim 14, further comprising an anti-reflective coating on to the substrate.

22. The pulse shaper of claim 14, further comprising a reflective coating on to the substrate.

23. The pulse shaper of claim 14, further comprising a rotatable wheel including multiple substrates, each with different fixed shaping characteristics.

24. A laser beam pulse shaping system comprising a mirror including a preset shaping pattern thereon, and a phase of a laser pulse being tailored with the mirror.

25. The pulse shaping system of claim 24, further comprising multiple dichroic layers on the mirror.

26. The pulse shaping system of claim 24, wherein the mirror is chirped.

27. The pulse shaping system of claim 24, wherein the mirror has a fixed two-dimensional wave pattern.

28. The pulse shaping system of claim 24, wherein the preset mirror introduces multiphoton intrapulse interference in the pulse without computer control of the mirror.

29. The pulse shaping system of claim 24, further comprising using the mirror to assist in determining and characterizing the phase of the pulse.

30. The pulse shaping system of claim 24, wherein multiple preset, shaping patterns on the mirror are offset as a function of the phase.

31. The pulse shaping system of claim 24, wherein the mirror includes a polymeric substrate.

32. The pulse shaping system of claim 24, wherein the pattern includes a sine wave which repeats across the mirror with adjacent rows of the pattern being offset from each other.

33. The pulse shaping system of claim 24, wherein the pulse has a duration of less than 11 femtoseconds.

34. A laser beam pulse shaping system comprising a mirror including a fixed two-dimensional wave pattern, and the mirror acting as a pulse shaper to introduce multiphoton intrapulse interference in a laser pulse in a preset manner free of computer control of the mirror pattern.

35. The pulse shaping system of claim 34, further comprising multiple dichroic layers on the mirror.

36. The pulse shaping system of claim 34, wherein the mirror is chirped.

37. The pulse shaping system of claim 34, further comprising using the mirror to assist in determining and characterizing a phase of the pulse.

38. The pulse shaping system of claim 34, wherein multiple shaping patterns are offset as a function of phase of the pulse.

39. The pulse shaping system of claim 34, wherein the mirror includes a polymeric substrate.

40. The pulse shaping system of claim 34, wherein the pattern is a sine wave which repeats across the mirror with adjacent rows of the pattern being offset from each other.

41. The pulse shaping system of claim 34, wherein the pulse has a duration of less than 11 femtoseconds.

42. A laser beam pulse shaper system comprising a laser beam pulse and a device including a predetermined and fixed pulse shaping pattern, the device shaping the pulse to reduce undesired nonlinear optical distortions in the pulse.

43. The pulse shaping system of claim 42, wherein the pattern is based on a quadratic function.

44. The pulse shaping system of claim 42, wherein the pattern is based on a sine wave.

45. The pulse shaping system of claim 42, wherein the device includes a fixed optical substrate containing the pattern.

46. The pulse shaping system of claim 42, wherein the device introduces multiphoton intrapulse interference in the pulse without computer control of the device.

47. The pulse shaping system of claim 42, wherein the device is a pulse shaping mirror.