Femtosecond laser pulse measuring system
| Title: | Femtosecond laser pulse measuring system |
|---|---|
| Patent Number: | 4,681,436 |
| Publication Date: | July 21, 1987 |
| Appl. No: | 06/706,590 |
| Application Filed: | February 28, 1985 |
| Abstract: | A system for measuring laser pulse durations in the range of ten nanoseconds to one femtosecond to an accuracy of one femtosecond, includes a primary pulse sampler, a ten component beam splitter array, optical delay lines whose settings are microprocessor controlled, a ten section interaction chamber with ten sets of ion detectors and a pulse envelope and pulse energy display monitors. The system has applications in chemistry, calibration of fast timing circuits and in the development of short pulse lasers. |
| Inventors: | Ching, Neng H. (Sydney NSW, AUX); Marson, Ralph G. (Sydney NSW, AUX); Norman, Michael J. (Canberra City 2601 ACT, AUX); Hughes, John L. (Torrens, Canberra ACT 2607, AUX) |
| Claim: | We claim |
| Claim: | 1. Apparatus for measuring the profile of a single laser pulse to an accuracy of a femtosecond, in the pulse duration range of one nanosecond to one femtosecond, comprising |
| Claim: | means for diverting a portion of said single pulse; |
| Claim: | means for splitting the diverted portion into N split portions, N being an integer greater than one; |
| Claim: | means for splitting each of said N portions into first and second components; |
| Claim: | means for independently delaying each of said first and second components of each of said N portions, and for adjusting the delayed first and second components of each of said N portions so that the delayed first and second components of said N portions are overlapped to varying degrees; |
| Claim: | means for expanding the delayed first and second components of each of said N portions; |
| Claim: | means for focusing the expanded first and second components of each of said N portions; |
| Claim: | interaction chamber means containing a low pressure gas, for ionizing said gas with the focused first and second components of each of said N portions, said interaction chamber means having exit window means through which the first and second components of each of said N portions exit; |
| Claim: | ion detector means, coupled to said interaction chamber means, for detecting the ions produced by the focused first and second components of each of said N portions and outputting electrical signals corresponding respectively thereto; |
| Claim: | processing means for receiving the electrical signals from said ion detector means; |
| Claim: | energy detector means for receiving the first and second components of each of said N portions exiting said exit window means of said interaction chamber means, and for providing output signals corresponding to a pulse duration and a total energy of each of said N portions; and |
| Claim: | monitor means for receiving said output signals and providing a display of the envelope and duration of said single laser pulse. |
| Claim: | 2. Apparatus according to claim 1 wherein said delaying means includes N adjustable delay devices for respectively delaying the first components of said N portions, and N stationary delay devices for respectively delaying the second components of said N portions. |
| Claim: | 3. Apparatus according to claim 2 wherein said processing means is coupled to said N adjustable delay devices for selectively adjusting the delay of said first components to produce varing degrees of overlap between the first and second components of each of said N portions. |
| Claim: | 4. Apparatus according to claim 1 wherein said interaction chamber means includes means for providing potential voltage gradients inside said interaction chamber means to accelerate the first and second components of each of said N portions. |
| Claim: | 5. Apparatus according to claim 1 wherein said means for diverting includes a beam splitter. |
| Claim: | 6. Apparatus according to claim 1 wherein said means for splitting the diverted portion includes a plurality of beam splitters. |
| Claim: | 7. Apparatus according to claim 1 wherein N is equal to 10. |
| Claim: | 8. Apparatus according to claim 1 wherein said means for splitting said N portions includes a plurality of beam splitters and a plurality of mirrors. |
| Claim: | 9. Apparatus according to claim 1 wherein means for independently delaying includes N delay devices. |
| Claim: | 10. Apparatus according to claim 1 wherein said means for expanding includes N beam expanders, and wherein said means for focusing includes N objective lenses, and wherein said ion detector means includes N ion detectors, and wherein said interaction chamber means includes N exit windows. |
| Claim: | 11. Apparatus according to claim 1 wherein said energy detector means includes N energy detectors. |
| Claim: | 12. Apparatus according to claim 1 further including optical detector means, optically coupled to said means for delaying, for detecting the optical condition of said means for delaying, and for providing output signals to said processing means. |
| Claim: | 13. Apparatus according to claim 12 wherein said optical detector means includes N optical detectors. |
| Claim: | 14. Apparatus according to claim 1 wherein said gas includes nitrogen. |
| Claim: | 15. Apparatus according to claim 1 wherein said monitor means includes first and second monitors. |
| Current U.S. Class: | 356/121; 356/213; 356/222 |
| Current International Class: | G01J 104; G01J 142 |
| Patent References Cited: | 4256962 March 1981 Horton et al. 4327285 April 1982 Bradley 4434399 February 1984 Mourou et al. 4447151 May 1984 McLellan et al. 4548496 October 1985 Roberts et al. |
| Other References: | Honda et al, "Measurements of Picosecond Laser Pulses from Mode-Locked Nd: Yag Laser", 1976 Conference on Precision Electromagnetic Measurements, Boulder, Colo., U.S.A. (Jun. 28-Jul. 1, 1976) pp. 33-34. |
| Primary Examiner: | McGraw, Vincent P. |
| Attorney, Agent or Firm: | Cushman, Darby & Cushman |
| Accession Number: | edspgr.04681436 |
| Database: | USPTO Patent Grants |
| Language: | English |
|---|