Patent US4627066A successfully refreshed from Google Patents.
US4627066A
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Excimer laser pumped by dissociative recombination
Assignee: University of Iowa Research Foundation
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Filing: 1984-05-08
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Granted: 1986-12-02
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Expires: 2004-05-08
Abstract
Abstract A preferred embodiment of an excimer laser has a heat pipe oven adapted to raise sodium therein to a temperature of about 800 Kelvin and thereby vaporize the sodium at a pressure of no more than about 0.1 atmosphere, the heat pipe oven having substantially transparent ends. A ring cavity made up of a plurality of mirrors and an adjustable birefringent filter circulates violet light of a desired wavelength through the transparent ends of the heat pipe oven, and a pump laser introduces radiation into the heat pipe oven at an energy high enough to ionize sodium therein to form Na 3 + ions and free electrons. The recombination of Na 3 + ions and free electrons causes the ions to dissociate into free sodium atoms and excited Na 2 molecules which, when stimulated by violet light of the desired wavelength, further dissociate into two free sodium atoms and emit additional violet light of the desired wavelength.
Inventors
- 👤 William C. Stwalley
- 👤 Mark E. Koch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:32
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/14; H01S3/22; H01S3/223; H01S3/225; H01S3/09; H01S3/095; H01S3/09505
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
175 words
A method of producing coherent electromagnetic radiation comprising providing a lasing medium having present at least one of species ARX, AR, R, X or A; R, X and A each being an atom or a molecular fragment said fragment consisting of one or more elements; ARX being ionizable to form ARX + ; ARX + having the property that upon recombination with an energetic electron it dissociates to form X, and AR in an excited state, such that AR in the excited state may emit electromagnetic radiation of a selected wavelength when stimulated by electromagnetic radiation at a wavelength in the range being emitted by AR in an electronically excited state and dissociate into A and R, ionizing at least a portion of ARX species in the lasing medium to form ARX + and free electrons, recombining ARX + with said free electrons to form AR in the excited state and X, and stimulating AR in the excited state with said similar electromagnetic radiation to thereby produce coherent electromagnetic radiation and at least two fragments.
Claim 2
Independent Claim
175 words
A method of producing coherent electromagnetic radiation comprising providing a lasing medium having present at least one of species ARX, AR, R, X or A; R, X and A each being an atom or a molecular fragment said fragment consisting of one or more elements; ARX being ionizable to form ARX + ; ARX + having the property that upon recombination with an energetic electron it dissociates to form X, and AR in an excited state, such that AR in the excited state may emit electromagnetic radiation of a selected wavelength when stimulated by electromagnetic radiation at a wavelength in the range being emitted by AR in an electronically excited state and dissociate into A and R, ionizing at least a portion of ARX species in the lasing medium to form ARX + and free electrons, recombining ARX + with said free electrons to form AR in the excited state and X, and stimulating AR in the excited state with said similar electromagnetic radiation to thereby produce coherent electromagnetic radiation and at least two fragments.
Claim 3
Independent Claim
194 words
A method of producing coherent electromagnetic radiation from a lasing medium in which electromagnetic radiation is emited as a result of an energy level transistion from a higher energy level state of a molecule R n+p to a lower energy level including separate species R p and R n , the molecule R n+p is the product of dissociative recombination of the molecular ion R + n+m+p with an electron; m, n and p are positive integers having a sum in the range of three to at least 14, inclusive; comprising the following steps ionizing at least a portion of R to form R + n+m+p and free electrons, wherein R is an atom capable of being ionized to form molecular ions, R n+p , R p and R n ; subjecting R + n+m+p to dissociative recombination with said free electrons thereby to form R n+p in an electronically excited state, and stimulating R n+p with electromagnetic radiation at a wavelength in the range being emitted by R n+p in said electronically excited state, whereby the emitted electromagnetic radiation stimulates further R n+p →R n +R p transitions in other R n+p molecules.
Claim 4
Independent Claim
194 words
A method of producing coherent electromagnetic radiation from a lasing medium in which electromagnetic radiation is emited as a result of an energy level transistion from a higher energy level state of a molecule R n+p to a lower energy level including separate species R p and R n , the molecule R n+p is the product of dissociative recombination of the molecular ion R + n+m+p with an electron; m, n and p are positive integers having a sum in the range of three to at least 14, inclusive; comprising the following steps ionizing at least a portion of R to form R + n+m+p and free electrons, wherein R is an atom capable of being ionized to form molecular ions, R n+p , R p and R n ; subjecting R + n+m+p to dissociative recombination with said free electrons thereby to form R n+p in an electronically excited state, and stimulating R n+p with electromagnetic radiation at a wavelength in the range being emitted by R n+p in said electronically excited state, whereby the emitted electromagnetic radiation stimulates further R n+p →R n +R p transitions in other R n+p molecules.
Claim 5
Dependent Claim
25 words
A method as claimed in claim 2 wherein R is selected from the group consisting of hydrogen, lithium, potassium, sodium, cesium, rubidium, nitrogen and mercury.
Claim 6
Dependent Claim
14 words
A method as claimed in claim 2 in which R is an alkali metal.
Claim 7
Dependent Claim
12 words
A method as claimed in claim 4 in which n=1 and p=1.
Claim 8
Dependent Claim
16 words
A method as claimed in claim 2 in which R is sodium, m=1, n=1 and p=1.
Claim 9
Dependent Claim
31 words
A method as claimed in claim 2 in which the method is carried out under controlled conditions and R + n+m+p is the predominant ionic form of R under the conditions.
Claim 10
Independent Claim
110 words
A method of producing coherent electromagnetic radiation comprising the steps of vaporizing an alkali metal in a heating means, introducing into said heating means energy selected to ionize a polyatomic species of the vapor of said alkali metal, whereby polyatomic species of said alkali metal ionized by said energy recombine with free electrons in said heating means to cause dissociation of said polyatomic species into allotropes thereof, one of said allotropes subsequently emitting electromagnetic radiation when stimulated by similar radiation and dissociating into further allotropes, and introducing said similar radiation to said heating means to stimulate the said allotrope to emit electromagnetic radiation coherent with said similar radiation and dissociate.
Claim 11
Independent Claim
110 words
A method of producing coherent electromagnetic radiation comprising the steps of vaporizing an alkali metal in a heating means, introducing into said heating means energy selected to ionize a polyatomic species of the vapor of said alkali metal, whereby polyatomic species of said alkali metal ionized by said energy recombine with free electrons in said heating means to cause dissociation of said polyatomic species into allotropes thereof, one of said allotropes subsequently emitting electromagnetic radiation when stimulated by similar radiation and dissociating into further allotropes, and introducing said similar radiation to said heating means to stimulate the said allotrope to emit electromagnetic radiation coherent with said similar radiation and dissociate.
Claim 12
Dependent Claim
24 words
A method as claimed in claim 8 wherein the partial pressure of said vapor in said heating means does not exceed about 0.1 atmospheres.
Claim 13
Dependent Claim
18 words
A method as claimed in claim 8 wherein the temperature in said heating means is about 800 Kelvin.
Claim 14
Dependent Claim
52 words
A method as claimed in claim 8 wherein the energy selected to ionize is an emission from a laser selected from the group consisting of (a) a continuous krypton ion laser, (b) a continuous argon ion laser, (c) a pulsed xenon fluoride excimer laser, and (d) a pulsed, frequency-tripled Neodymium YAG laser.
Claim 15
Dependent Claim
26 words
A method as claimed in claim 8 wherein the ionizing laser emission is introduced to a ring cavity of which the heating means is a portion.
Claim 16
Dependent Claim
24 words
A method as claimed in claim 12 including tuning the wavelength of the coherent radiation by adjusting a birefringent filter within the ring cavity.
Claim 17
Dependent Claim
164 words
An excimer laser comprising a vaporous lasing medium having present at least one of species ARX, AR, R, X or A; R, X and A each being one or more elements; ARX being ionizable to form ARX + , ARX + having the property that upon recombination with an energetic electron it dissociates to form X and AR in an excited state, such that AR in the excited state may emit electromagnetic radiation of a selected wavelength when stimulated by electromagnetic radiation at a wavelength in the range being emitted by AR in an electronically excited state and dissociate into A and R, means for ionizing at least a portion of the ARX species of said lasing medium to form ARX + and free electrons, means for recombining ARX + with said free electrons to form AR in an excited state and X, and means for stimulating AR to emit electromagnetic radiation of the selected wavelength and dissociate, said laser producing coherent electromagnetic radiation.
Claim 18
Dependent Claim
164 words
An excimer laser comprising a vaporous lasing medium having present at least one of species ARX, AR, R, X or A; R, X and A each being one or more elements; ARX being ionizable to form ARX + , ARX + having the property that upon recombination with an energetic electron it dissociates to form X and AR in an excited state, such that AR in the excited state may emit electromagnetic radiation of a selected wavelength when stimulated by electromagnetic radiation at a wavelength in the range being emitted by AR in an electronically excited state and dissociate into A and R, means for ionizing at least a portion of the ARX species of said lasing medium to form ARX + and free electrons, means for recombining ARX + with said free electrons to form AR in an excited state and X, and means for stimulating AR to emit electromagnetic radiation of the selected wavelength and dissociate, said laser producing coherent electromagnetic radiation.
Claim 19
Dependent Claim
17 words
A laser as claimed in claim 14 wherein A, R and X are all the same element.
Claim 20
Dependent Claim
15 words
A laser as claimed in claim 14 wherein A, R and X are all sodium.
Claim 21
Dependent Claim
17 words
A laser as claimed in claim 14 wherein A, R and X are all an alkali metal.
Claim 22
Dependent Claim
15 words
A laser as claimed in claim 14 wherein said means for ionizing comprises a laser.
Claim 23
Dependent Claim
24 words
A laser as claimed in claim 14 wherein said means for stimulating includes a ring cavity which reintroduces emitted radiation to the lasing medium.
Claim 24
Dependent Claim
19 words
A laser as claimed in claim 12 wherein said lasing medium is made vaporous in a heat pipe oven.
Claim 25
Dependent Claim
51 words
A laser as claimed in claim 20 wherein said heat pipe oven has substantially transparent ends and wherein said means for stimulating includes a ring cavity of which said heat pipe oven is a part, whereby emitted radiation can be reintroduced through one of said transparent ends to said lasing medium.
Claim 26
Dependent Claim
155 words
An excimer laser comprising a heat pipe oven adapted to raise sodium therein to a temperature of about 800 Kelvin and vaporize said sodium at a partial pressure of no more than about 0.1 atmosphere, said heat pipe oven having substantially transparent ends, a ring cavity comprising a plurality of mirrors and an adjustable birefringent filter to circulate violet light of a desired wavelength through said transparent ends of said heat pipe oven and a pump laser arranged to introduce radiation into said heat pipe oven at an energy high enough to ionize sodium therein to form Na 3 + ions and free electrons, whereby the recombination of Na 3 + ions and free electrons will cause the ions to dissociate into free sodium atoms and excited Na 2 molecules which, when stimulated by violet light of the desired wavelength, emit additional violet light of the desired wavelength and dissociate into two free sodium atoms.
Claim 27
Dependent Claim
155 words
An excimer laser comprising a heat pipe oven adapted to raise sodium therein to a temperature of about 800 Kelvin and vaporize said sodium at a partial pressure of no more than about 0.1 atmosphere, said heat pipe oven having substantially transparent ends, a ring cavity comprising a plurality of mirrors and an adjustable birefringent filter to circulate violet light of a desired wavelength through said transparent ends of said heat pipe oven and a pump laser arranged to introduce radiation into said heat pipe oven at an energy high enough to ionize sodium therein to form Na 3 + ions and free electrons, whereby the recombination of Na 3 + ions and free electrons will cause the ions to dissociate into free sodium atoms and excited Na 2 molecules which, when stimulated by violet light of the desired wavelength, emit additional violet light of the desired wavelength and dissociate into two free sodium atoms.
References Cited (Backward Citations)
US4087765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-12-01 | 1990-06-02 | 1990-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-01 | 1994-06-02 | 1994-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-01 | 1998-06-02 | 1998-12-02 | $7700.00 | Window Closed / Lapsed |