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US3836867A
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Gas breakdown laser pulse selector
Assignee: RTX Corp
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Filing: 1973-03-27
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Granted: 1974-09-17
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Expires: 1993-03-27
Abstract
Abstract A single pulse or a selected number of pulses from a mode-locked laser may be isolated from the laser pulse train. A gas breakdown cell is positioned in the path of the laser pulse train and the laser pulses are focused within the cell. When the intensity of the pulses exceeds the gas breakdown threshold, a plasma is generated which acts as a highly reflecting mirror. In the preferred embodiment using a ring cavity geometry, the laser pulse train travels through the cell in one direction and the gas pressure in the cell is adjusted so that breakdown of the gas occurs near the peak intensity of the traveling pulse. The breakdown plasma reflects a portion of the breakdown pulse which propagates in the opposite direction from the original pulse train. A single nonmode-locked laser pulse may be shaped by using the reflection capabilities of the breakdown plasma formed in a gas cell.
Inventors
- 👤 D Smith
- 👤 P Solomon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:52
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/10; H01S3/11; H01S3/1106; H01S3/1112; H01S3/05; H01S3/08; H01S3/081; H01S3/083; H01S3/105; H01S3/106; H01S3/1068; H01S3/1103; H01S3/1109
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
180 words
A laser pulse selector comprising means for generating a train of mode-locked laser pulses, means for propagating said pulse train in a preselected direction, a variable pressure gas breakdown cell having a first lens forming a wall thereof and filled with a pressurized gas forming a plasma when said gas is energized to a specified power density, a partially transmitting mirror positioned in the path of said pulse train for reflecting said pulse train therefrom in a direction to intersect said first lens, means including said first lens for focusing said laser pulse train at a point within said gas cell and producing a power density sufficiently high to form a gas plasma therein, means including said plasma for reflecting from said gas cell the portion of the laser pulse train incident thereon during the existence of said plasma and propagating said reflected laser pulses along a path opposite the path of said incident pulse train toward said partially transmitting mirror, and means including said partially transmitting mirror for passing therethrough at least a portion of said reflected laser pulses.
Claim 2
Dependent Claim
180 words
A laser pulse selector comprising means for generating a train of mode-locked laser pulses, means for propagating said pulse train in a preselected direction, a variable pressure gas breakdown cell having a first lens forming a wall thereof and filled with a pressurized gas forming a plasma when said gas is energized to a specified power density, a partially transmitting mirror positioned in the path of said pulse train for reflecting said pulse train therefrom in a direction to intersect said first lens, means including said first lens for focusing said laser pulse train at a point within said gas cell and producing a power density sufficiently high to form a gas plasma therein, means including said plasma for reflecting from said gas cell the portion of the laser pulse train incident thereon during the existence of said plasma and propagating said reflected laser pulses along a path opposite the path of said incident pulse train toward said partially transmitting mirror, and means including said partially transmitting mirror for passing therethrough at least a portion of said reflected laser pulses.
Claim 3
Dependent Claim
120 words
A laser pulse selector as in claim 1 in which said means for generating a train of mode-locked laser pulses includes a laser gain medium inserted along the optical path in one leg of a ring resonator, said resonator also including said partially transmitting mirror, and said gas cell including a second lens positioned in the wall of said gas cell opposite said one lens, said gas cell being located in one leg of said ring resonator other than the leg containing said laser gain medium and in said resonator optical path and passing through said first and second lenses the portion of the laser pulse train incident thereon prior to the generation of said plasma within said gas cell.
Claim 4
Dependent Claim
45 words
A laser pulse selector as in claim 2 in which said means for causing said laser pulse train to propagate within said ring resonator in a preselected direction is an acousto-optic modulator positioned in a leg of said resonator and in the optical path thereof.
Claim 5
Dependent Claim
78 words
A laser pulse selector as in claim 1 in which said gas cell includes second and third lenses forming opposite walls thereof and said one lens forming a wall of said cell at right angles to said second and third lenses, said propagating means directing said laser pulse train through said second and third lenses toward said partially transmitting mirror, and means including said second lens for focusing said laser pulses at said point within said gas cell.
Claim 6
Dependent Claim
63 words
A laser pulse selector as in claim 1 and including a second gas cell having second and third lenses positioned in the path of said laser pulse train and passing therethrough toward said partially reflecting mirror the initial portion of said laser pulse train prior to breakdown of a gas in said second cell and attenuation of the remainder of said pulse train.
Claim 7
Dependent Claim
160 words
A laser pulse selector comprising a ring resonator including a plurality of mirrors, at least, one of said mirrors being partially transmitting, a laser gain medium positioned in one leg of said resonator, means for generating a train of mode-locked laser pulses, means for propagating said pulse train about said resonator in a selected direction, a gas cell having first and second lenses forming opposite walls thereof positioned in the optical path within another leg of said resonator, said gas cell containing a pressurized gas, means including said first lens for focusing said laser pulse train within said gas cell to cause breakdown of said gas and formation of a plasma, means including said plasma for reflecting from said gas cell in a direction opposite said selected direction the portion of the laser pulse train incident thereon during the existence of said plasma, and means including said partially transmitting mirror for passing said reflected laser pulses out of said resonator.
Claim 8
Dependent Claim
160 words
A laser pulse selector comprising a ring resonator including a plurality of mirrors, at least, one of said mirrors being partially transmitting, a laser gain medium positioned in one leg of said resonator, means for generating a train of mode-locked laser pulses, means for propagating said pulse train about said resonator in a selected direction, a gas cell having first and second lenses forming opposite walls thereof positioned in the optical path within another leg of said resonator, said gas cell containing a pressurized gas, means including said first lens for focusing said laser pulse train within said gas cell to cause breakdown of said gas and formation of a plasma, means including said plasma for reflecting from said gas cell in a direction opposite said selected direction the portion of the laser pulse train incident thereon during the existence of said plasma, and means including said partially transmitting mirror for passing said reflected laser pulses out of said resonator.
References Cited (Backward Citations)
US3433555A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |