Control system and apparatus for use with ultra-fast laser

• US 20060187974A1
• Filed: 09/02/2005
• Published: 08/24/2006
• 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: Dantus, Marcos
• Granted Patent: US 7,973,936 B2
• Time in Patent Office: Days
• US Class Current: 372/9
• CPC Class Codes: G01J 11/00 Measuring the characteristics of individual optical pulses or of optical pulse trains
• CPC Class Codes: G01J 3/00 Spectrometry; Spectrophotometry; Monochromators; Measuring colours
• CPC Class Codes: G01N 21/00 Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light G01N3/00 - G01N19/00 take precedence
• CPC Class Codes: H01J 49/164 Laser desorption/ionisation, e.g. matrix-assisted laser desorption/ionisation [MALDI] sample holders H01J49/0418
• CPC Class Codes: H01S 3/0014 Monitoring arrangements not otherwise provided for photometry G01J1/00, e.g. G01J1/4257; radiation pyrometry G01J5/00; measuring coherence of light G01J9/00; measuring wavelength of light G01J9/00, e.g. G01J9/0246; measuring optical pulses G01J11/00; calorimetrically measuring power of laser beams G01K17/003
• 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 control system and apparatus for use with an ultra-fast laser is provided. In another aspect of the present invention, the apparatus includes a laser, pulse shaper, detection device and control system. A multiphoton intrapulse interference method is used to characterize the spectral phase of laser pulses and to compensate any distortions in an additional aspect of the present invention. In another aspect of the present invention, a system employs multiphoton intrapulse interference phase scan. Furthermore, another aspect of the present invention locates a pulse shaper and/or MIIPS unit between a laser oscillator and an output of a laser amplifier.

Claims

1. A computer software product in computer readable medium for utilizing data from a phase scan to thereby extract the maxima from the phase scan for a function parameter to obtain the second derivative of the phase φ

(ω

), the computer software product comprising;

first instructions for initiating a program;

second instructions for initializing parameters;

third instructions for acquiring a new phase scan;

fourth instructions for applying −

φ

(ω

) to correct said phase;

fifth instructions for determining if the target phase residue is reached;

sixth instructions for recording and displaying final correction data; and

seventh instructions for halting said program.

2. The computer software product as recited in claim 1, wherein said second instructions for initializing parameters comprises calibrating wavelength and phase scales to establish initial parameters for phase scan (α

,γ

,δ

) using a reference function dependent on said initial parameters f(α

,γ

,δ

) and a target residual phase.

3. The computer software product as recited in claim 1, wherein said fourth instructions for applying −

φ

(ω

) to correct said phase comprises extracting maxima from the phase scan for parameter of the function and integrating the obtained φ

″

(ω

) to get a phase across the whole spectrum, φ

(ω

).

4. The computer software product as recited in claim 1, wherein said fifth instructions further includes adjusting acquisition parameters in the event that it is determined that said target phase residue is not reached.

5. The computer software product as recited in claim 4, wherein said fifth instructions further includes adding −

φ

(ω

) from the previous iteration to the applied compensation function in the event that it is determined that said target phase residue is not reached.

6. A computer software product in computer readable medium for effecting movement of optic hardware to correct phase distortions, the computer software product comprising:

first instructions for initiating a program.

second instructions for initializing parameters;

third instructions for acquiring a new phase scan;

fourth instructions for automatically adjusting the optic hardware;

fifth instructions for determining if the quadratic and cubic phase residue has been reached;

sixth instructions for acquiring a new phase scan;

seventh instructions for applying −

φ

(ω

) to correct said new phase;

eighth instructions for determining if the target phase residue has been reached;

ninth instructions for recording and displaying final correction data;

tenth instructions for storing a compensation phase file and output corrective parameters; and

eleventh instructions for halting said program.

7. The computer software product as recited in claim 6, wherein said second instructions for initializing parameters comprises calibrating wavelength and phase scales.

8. The computer software product as recited in claim 6, wherein said second instructions for initializing parameters comprises initializing a phase compensation φ

(ω

).

9. The computer software product as recited in claim 6, wherein said second instructions for initializing parameters comprises setting initial parameters for a phase scan (α

,γ

,δ

) using a reference function dependent on said initial parameters f(α

,γ

,δ

) and a target residual phase.

10. The computer software product as recited in claim 6, wherein said fourth instructions for automatically adjusting the optic hardware comprises calculating the sign and magnitude of correction.

11. The computer software product as recited in claim 6, wherein said fourth instructions for automatically adjusting the optic hardware comprises repeating the automatic adjustment of the optic hardware.

12. The computer software product as recited in claim 6, wherein if in said fifth instructions for determining if the quadratic and cubic phase residue has been reached it is determined that said quadratic and cubic phase residue has not been reached, the steps are repeated beginning with said third instructions for acquiring a new phase scan until it is determined that the phase residue queried in said fifth instructions has been reached.

13. The computer software product as recited in claim 6, wherein the new phase scan of the sixth instruction is acquired through a supplemental computer software product comprising:

first instructions for initiating a program;

second instructions for initializing parameters;

third instructions for acquiring a new phase scan;

fourth instructions for applying −

φ

(ω

) to correct said phase;

fifth instructions for determining if the target phase residue is reached;

sixth instructions for recording and displaying final correction data; and

seventh instructions for halting said program.

14. The computer software product as recited in claim 6, wherein the seventh instructions for applying −

φ

(ω

) to correct said new phase comprises extracting maxima from said phase scan for the parameter of the function.

15. The computer software product as recited in claim 6, wherein the seventh instructions for applying −

φ

(ω

) to correct said new phase comprises integrating the obtained φ

″

to obtain a phase across the whole spectrum, φ

(ω

).

16. The computer software product as recited in claim 6, wherein if in said eighth instructions for determining if the target phase residue has been reached it is determined that said target phase residue has not been reached, then the parameters are checked and adjusted.

17. The computer software product as recited in claim 16, wherein −

φ

(ω

) is added from the previous iteration to the applied compensation function φ

(ω

).

18. The computer software product as recited in claim 19, wherein if in said eighth instructions for determining if the target phase residue has been reached it is determined that said target phase residue has not been reached then the steps are repeated beginning with said sixth instructions for acquiring a new phase scan until it is determined that the phase residue queried in said eighth instructions has been reached.

19. The computer software product as recited in claim 6, wherein the tenth instructions for storing a phase compensation file and output corrective parameters comprises adjusting hardware settings and the accumulated φ

(ω

).

20. A computer software product in computer readable medium for fine tuning a phase function through comparison of an experimental spectrum and a theoretical spectrum and by subsequent adjustments until the selected spectrum is achieved, the computer software product comprising:

first instructions for initiating a program;

second instructions for initializing parameters;

third instructions for acquiring an SHG spectrum;

fourth instructions for generating a theoretical spectrum;

fifth instructions for determining if the target residue is reached through a comparison with the desired output;

sixth instructions for recording and displaying the final correction data; and

seventh instructions for halting said program.

21. The computer software product as recited in claim 20, wherein said second instructions for initializing parameters comprises selecting a calibration function and its parameter.

22. The computer software product as recited in claim 20, wherein if in said fifth instructions for determining if the target residue has been reached it is determined that said target residue has not been reached then a calculation is made for the requisite adjustment and the phase parameters are adjusted.

23. The computer software product as recited in claim 22, wherein the steps are repeated beginning with said third instructions for acquiring an SHG spectrum until it is determined that the target residue queried in said fifth instructions has been reached.

24. A computer software product in computer readable medium for fine tuning of the amplitude of the output spectrum of a laser by comparing the desired output with the experimentally-measured output and by subsequent adjustments until the desired spectrum is achieved, the computer software product comprising:

first instructions for initiating a program;

second instructions for initializing parameters;

third instructions for acquiring an output spectrum;

fourth instructions for determining if the target residue is reached;

fifth instructions for recording and displaying final correction data; and

25. The computer software as recited in claim 24, wherein said second instructions for initializing parameters comprises the user selecting output parameters.

26. The computer software as recited in claim 24, wherein said fourth instructions for determining if the target residue is reached comprises comparing the achieved residue with the desired output.

27. The computer software as recited in claim 26, wherein if in said fourth instructions for determining if the target residue has been reached it is determined that said target residue has not been reached then a required adjustment calculation is made and the amplitude parameters are adjusted.

28. The computer software as recited in claim 27, wherein the steps are repeated beginning with said third instructions for acquiring an output spectrum until it is determined that the target residue queried in said fourth instructions has been reached.