US5149406A
Expired / Lapsed
US
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Electrical field quenching of optical breakdown
Assignee: The AT&T MVPD Group LLC
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Filing: 1989-08-03
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Granted: 1992-09-22
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Expires: 2009-08-03
Abstract
Abstract Optical breakdown in a transparent, non-linear medium used for optical phase conjugation or the like is induced by interaction with the medium of a strong laser beam propagating therethrough, resulting from electron avalanche breakdown and plasma formation. Application of an electrical potential to electrodes disposed across the laser focal volume in the medium causes optically and/or electrically ionized impurities to be removed from the non-linear medium and attached to the electrodes, thereby purifying the medium and raising the optical breakdown threshold. The threshold may be further raised by adjusting the electric potential to a magnitude at which free electrons are removed from the laser focal volume either during an optical pulse or before the arrival of subsequent pulses.
Inventors
- 👤 Ruth A. Mullen
- 👤 Robert W. Hellwarth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:01
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/30; H01S3/305; G; G02; G02F; G02F1/00; G02F1/35; G02F1/353; G02F1/3536; G02F1/3538
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
97 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a medium; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical field across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, the magnitude of said electrical potential being selected to produce an electric field voltage across said optical interaction volume that is substantially less than the medium's electrical breakdown voltage.
Claim 2
Independent Claim
97 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a medium; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical field across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, the magnitude of said electrical potential being selected to produce an electric field voltage across said optical interaction volume that is substantially less than the medium's electrical breakdown voltage.
Claim 3
Dependent Claim
22 words
A method as in claim 1, in which step (a) comprises providing the medium in the form of a transparent, non-linear gas.
Claim 4
Dependent Claim
53 words
A method as in claim 1, in which step (a) further comprises providing a cell for enclosing the medium, step (c) further comprising providing first and second electrodes positioned to create electric field lines passing through the interaction volume of the medium and applying the electrical potential across the first and second electrodes.
Claim 5
Dependent Claim
47 words
A method as in claim 3, in which said magnitude of the electrical potential in step (c) is sufficiently high to pull optically ionized impurities from the interaction volume of the medium and move the resulting ions to at least one of the first and second electrodes.
Claim 6
Dependent Claim
49 words
A method as in claim 4, in which steps (a) and (c) respectively comprise selecting a material composition of the medium and a material composition of the first and second electrodes in such a manner that ions moved to the first and second electrodes will substantially permanently adhere thereto.
Claim 7
Dependent Claim
34 words
A method as in claim 3, in which said magnitude of the electrical potential in step (c) is sufficiently high to cause movement of free electrons out of the interaction volume of the medium.
Claim 8
Dependent Claim
49 words
A method as in claim 1, in which step (a) further comprises providing a cell for enclosing the medium, step (c) further comprising providing first and second electrodes inside the cell across the interaction volume of the medium and applying the electrical potential across the first and second electrodes.
Claim 9
Dependent Claim
51 words
A method as in claim 1, in which step (a) further comprises providing an electrically non-conductive cell for enclosing the medium, step (c) further comprises providing first and second electrodes outside the cell across the interaction volume of the medium and applying the electrical potential across the first and second electrodes.
Claim 10
Dependent Claim
31 words
A method as in claim 1, in which step (b) further comprises focussing the laser beam in the medium, the optical interaction volume being the focal volume of the laser beam.
Claim 11
Independent Claim
168 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a nonlinear medium and a cell for enclosing the medium; (b) causing a laser beam to propagate through the medium in the form of pulses; (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to remove free electrons and quench optical breakdown of the medium induced by interaction of the laser beam with the medium by providing first and second electrodes positioned to create electric field lines passing through the interaction volume of the medium and applying the electrical potential across the first and second electrodes, said magnitude of the electrical potential being sufficiently high to cause movement of free electrons out of the interaction volume of the medium during time intervals between the pulses, but substantially less than that at which said electric fields equals the medium's threshold for electrical breakdown so that the electron density remains below a critical level at which avalanche breakdown begins to occur.
Claim 12
Independent Claim
168 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a nonlinear medium and a cell for enclosing the medium; (b) causing a laser beam to propagate through the medium in the form of pulses; (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to remove free electrons and quench optical breakdown of the medium induced by interaction of the laser beam with the medium by providing first and second electrodes positioned to create electric field lines passing through the interaction volume of the medium and applying the electrical potential across the first and second electrodes, said magnitude of the electrical potential being sufficiently high to cause movement of free electrons out of the interaction volume of the medium during time intervals between the pulses, but substantially less than that at which said electric fields equals the medium's threshold for electrical breakdown so that the electron density remains below a critical level at which avalanche breakdown begins to occur.
Claim 13
Independent Claim
106 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to quench optical breakdown of the medium induced by interaction of the laser beam with the medium, in which said magnitude of the electrical potential is sufficiently high to cause electrical ionization of impurities in the interaction volume and movement of the resulting ions out of the interaction volume, but substantially less than that required to initiate electrical breakdown of the medium.
Claim 14
Independent Claim
106 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to quench optical breakdown of the medium induced by interaction of the laser beam with the medium, in which said magnitude of the electrical potential is sufficiently high to cause electrical ionization of impurities in the interaction volume and movement of the resulting ions out of the interaction volume, but substantially less than that required to initiate electrical breakdown of the medium.
Claim 15
Independent Claim
128 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium in the form of trains of pulses; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, said magnitude of the electrical potential being selected to produce an electrical field voltage across said optical interaction volume that is less than the medium's electrical breakdown voltage and being sufficiently high to cause movement of free electrons out of the optical interaction volume during time intervals between pulse trains.
Claim 16
Independent Claim
128 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium in the form of trains of pulses; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, said magnitude of the electrical potential being selected to produce an electrical field voltage across said optical interaction volume that is less than the medium's electrical breakdown voltage and being sufficiently high to cause movement of free electrons out of the optical interaction volume during time intervals between pulse trains.
Claim 17
Independent Claim
123 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium in the form of pulses; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, said magnitude of the electrical potential being selected to produce an electrical field voltage across said optical interaction volume that is less than the medium's electrical breakdown voltage and being sufficiently high to cause movement of free electrons out of the optical interaction volume during the pulse.
Claim 18
Independent Claim
123 words
A method of quenching optical breakdown, comprising the steps of: (a) providing a non-linear medium having impurities; (b) causing a laser beam to propagate through the medium in the form of pulses; and (c) applying an electrical potential across an optical interaction volume of the medium of sufficient magnitude to increase an optical breakdown threshold of the medium and thereby quench optical breakdown of the medium induced by interaction of the laser beam with the medium, said magnitude of the electrical potential being selected to produce an electrical field voltage across said optical interaction volume that is less than the medium's electrical breakdown voltage and being sufficiently high to cause movement of free electrons out of the optical interaction volume during the pulse.
Claim 19
Independent Claim
160 words
A method of fabricating a cell filled with a transparent, purified, non-linear medium, comprising the steps of: (a) providing the cell filled with said medium in unpurified form, and first and second electrodes disposed inside the cell across an interaction volume of the medium; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical potential across the interaction volume of sufficient magnitude and for a sufficient length of time to cause ionization of impurities in the medium and movement of the resulting ions to at least one of the first and second electrodes, a material composition of the medium and a material composition of the first and second electrodes being selected in such a manner that the ions will substantially permanently adhere thereto after said length of time, the magnitude of said electrical potential being selected to produce an electric field across said interaction volume that is substantially less than the medium's electrical breakdown voltage.
Claim 20
Independent Claim
160 words
A method of fabricating a cell filled with a transparent, purified, non-linear medium, comprising the steps of: (a) providing the cell filled with said medium in unpurified form, and first and second electrodes disposed inside the cell across an interaction volume of the medium; (b) causing a laser beam to propagate through the medium; and (c) applying an electrical potential across the interaction volume of sufficient magnitude and for a sufficient length of time to cause ionization of impurities in the medium and movement of the resulting ions to at least one of the first and second electrodes, a material composition of the medium and a material composition of the first and second electrodes being selected in such a manner that the ions will substantially permanently adhere thereto after said length of time, the magnitude of said electrical potential being selected to produce an electric field across said interaction volume that is substantially less than the medium's electrical breakdown voltage.
Claim 21
Independent Claim
72 words
A method of quenching optical breakdown in a medium having an optical breakdown threshold and optical parameters, comprising the steps of: (a) causing a beam to propagate through the medium, and (b) applying an electrical potential across an optical interaction volume of said medium with a magnitude selected to increase the optical breakdown of said medium without affecting the optical parameters of said medium, and without exceeding the medium's electrical breakdown threshold.
Claim 22
Independent Claim
72 words
A method of quenching optical breakdown in a medium having an optical breakdown threshold and optical parameters, comprising the steps of: (a) causing a beam to propagate through the medium, and (b) applying an electrical potential across an optical interaction volume of said medium with a magnitude selected to increase the optical breakdown of said medium without affecting the optical parameters of said medium, and without exceeding the medium's electrical breakdown threshold.
References Cited (Backward Citations)
US3973213A
Cited
US4545878A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-09-22 | 1996-03-23 | 1996-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-22 | 2000-03-23 | 2000-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-22 | 2004-03-23 | 2004-09-22 | $7700.00 | Window Closed / Lapsed |