US4095121A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resonantly enhanced four-wave mixing
Assignee: United States Department of Energy
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Filing: 1977-04-14
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Granted: 1978-06-13
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Expires: 1997-04-14
Abstract
Abstract A method and apparatus for achieving large susceptibilities and long interaction lengths in the generation of new wavelengths in the infrared spectral region. A process of resonantly enhanced four-wave mixing is employed, utilizing existing laser sources, such as the CO 2 laser, to irradiate a gaseous media. The gaseous media, comprising NH 3 , CH 3 F, D 2 , HCl, HF, CO, and H 2 or some combination thereof, are of particular interest since they are capable of providing high repetition rate operation at high flux densities where crystal damage problems become a limitation.
Inventors
- 👤 Richard F. Begley
- 👤 Norman A. Kurnit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:47
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/353; G02F1/3534
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
112 words
A method for generating tunable infrared radiation by four-wave mixing in a molecular gas comprising the steps of: generating a first coherent, variable excitation signal ω 1 which is near resonant with at least one infrared transition of said molecular gas; generating second coherent, variable excitation signal ω 2 which is near resonant with at least one infrared transition of said molecular gas; irradiating said molecular gas with said first and second coherent, variable excitation signals in a waveguide to increase focal interaction length and enhance phase matching to increase efficiency; whereby ω 1 - ω 2 is resonant with a Raman allowed rotational transition thereby enhancing third order susceptibility and intensity.
Claim 2
Independent Claim
112 words
A method for generating tunable infrared radiation by four-wave mixing in a molecular gas comprising the steps of: generating a first coherent, variable excitation signal ω 1 which is near resonant with at least one infrared transition of said molecular gas; generating second coherent, variable excitation signal ω 2 which is near resonant with at least one infrared transition of said molecular gas; irradiating said molecular gas with said first and second coherent, variable excitation signals in a waveguide to increase focal interaction length and enhance phase matching to increase efficiency; whereby ω 1 - ω 2 is resonant with a Raman allowed rotational transition thereby enhancing third order susceptibility and intensity.
Claim 3
Dependent Claim
13 words
The method of claim 1 wherein said molecular gas comprises NH 3 .
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein said molecular gas comprises a mixture of NH 3 and a gas to further enhance phase matching.
Claim 5
Dependent Claim
12 words
The method of claim 3 wherein said gas comprises CH 3 F.
Claim 6
Dependent Claim
33 words
The method of claim 1 wherein said step of irradiating said molecular gas comprises: directing said first and second coherent, variable excitation signals in colinear beams; aligning said waveguide with said colinear beams.
Claim 7
Independent Claim
118 words
A device for generating a tunable infrared signal by four-wave mixing in a molecular gas comprising: means for generating a first excitation signal having a frequency ω 1 and a second excitation signal having a frequency ω 2 ; a chamber containing said molecular gas; a capillary waveguide disposed within said chamber; means for directing said first and second excitation signals through said capillary waveguide to irradiate said molecular gas and generate a tunable infrared signal by varying ω 1 and ω 2 ; whereby both ω 1 and ω 2 are near resonant with at least one infrared transition in said molecular gas and ω 1 - ω 2 is resonant with a Raman allowed rotational transition.
Claim 8
Independent Claim
118 words
A device for generating a tunable infrared signal by four-wave mixing in a molecular gas comprising: means for generating a first excitation signal having a frequency ω 1 and a second excitation signal having a frequency ω 2 ; a chamber containing said molecular gas; a capillary waveguide disposed within said chamber; means for directing said first and second excitation signals through said capillary waveguide to irradiate said molecular gas and generate a tunable infrared signal by varying ω 1 and ω 2 ; whereby both ω 1 and ω 2 are near resonant with at least one infrared transition in said molecular gas and ω 1 - ω 2 is resonant with a Raman allowed rotational transition.
Claim 9
Dependent Claim
18 words
The device of claim 6 wherein said chamber comprises a vacuum chamber having Brewster windows at each end.
Claim 10
Dependent Claim
17 words
The device of claim 6 wherein said capillary waveguide is tapered at one end to prevent ablation.
Claim 11
Dependent Claim
32 words
The device of claim 6 further comprising: a diffraction grating aligned with said capillary wave-guide to spatially disperse the various signals emitted from said waveguide; and means for detecting said various signals.
Claim 12
Dependent Claim
17 words
The device of claim 9 wherein said capillary waveguide is tapered at one end to prevent ablation.
Claim 13
Dependent Claim
13 words
The device of claim 6 wherein said molecular gas comprises NH 3 .
Claim 14
Dependent Claim
19 words
The device of claim 6 wherein said molecular gas comprises NH 3 plus a gas suitable for phase matching.
Claim 15
Independent Claim
155 words
A device for generating a tunable infrared signal by four-wave mixing in a molecular gas comprising: means for generating a first excitation signal having a frequency ω 1 and a second excitation signal having a frequency ω 2 ; chamber means for retaining said molecular gas and emitting said tunable infrared signal produced by four-wave mixing in said molecular gas in response to irradiation of said molecular gas by said first and second excitation signals in said chamber means; a capillary waveguide disposed within said chamber; means for directing said first and second excitation signals through said capillary waveguide to increase focal interaction length and phase matching thereby enhancing efficiency; whereby ω 1 and ω 2 are varied to vary the frequency of said tunable infrared signal and are near resonant with at least one infrared transition of said molecular gas and ω 1 - ω 2 is resonant with a Raman allowed rotational transition.
Claim 16
Independent Claim
155 words
A device for generating a tunable infrared signal by four-wave mixing in a molecular gas comprising: means for generating a first excitation signal having a frequency ω 1 and a second excitation signal having a frequency ω 2 ; chamber means for retaining said molecular gas and emitting said tunable infrared signal produced by four-wave mixing in said molecular gas in response to irradiation of said molecular gas by said first and second excitation signals in said chamber means; a capillary waveguide disposed within said chamber; means for directing said first and second excitation signals through said capillary waveguide to increase focal interaction length and phase matching thereby enhancing efficiency; whereby ω 1 and ω 2 are varied to vary the frequency of said tunable infrared signal and are near resonant with at least one infrared transition of said molecular gas and ω 1 - ω 2 is resonant with a Raman allowed rotational transition.
Claim 17
Dependent Claim
31 words
The device of claim 13 further comprising: a diffraction grating aligned with said capillary waveguide to spatially disperse various signals emitted from said waveguide; and means for detecting said various signals.
Claim 18
Independent Claim
114 words
A method for generating tunable infrared radiation by four-wave mixing in a molecular gas comprising the steps of: generating a first coherent, variable excitation signal ω 1 which is near resonant with at least one infrared transition of said molecular gas; generating a second coherent, variable excitation signal ω 2 which is near resonant with at least one infrared transition of said molecular gas; irradiating said molecular gas with said first and second coherent, variable excitation signals in a waveguide to increase focal interaction length and enhance phase matching to increase efficiency; whereby ω 1 - ω 2 is resonant with a Raman allowed rotational transition thereby enhancing third order susceptibility and output intensity.
Claim 19
Independent Claim
114 words
A method for generating tunable infrared radiation by four-wave mixing in a molecular gas comprising the steps of: generating a first coherent, variable excitation signal ω 1 which is near resonant with at least one infrared transition of said molecular gas; generating a second coherent, variable excitation signal ω 2 which is near resonant with at least one infrared transition of said molecular gas; irradiating said molecular gas with said first and second coherent, variable excitation signals in a waveguide to increase focal interaction length and enhance phase matching to increase efficiency; whereby ω 1 - ω 2 is resonant with a Raman allowed rotational transition thereby enhancing third order susceptibility and output intensity.
Claim 20
Dependent Claim
13 words
The method of claim 15 wherein said molecular gas comprises D 2 .
Claim 21
Dependent Claim
11 words
The method of claim 15 wherein said molecular gas comprises HCl.
Claim 22
Dependent Claim
11 words
The method of claim 15 wherein said molecular gas comprises HF.
Claim 23
Dependent Claim
11 words
The method of claim 15 wherein said molecular gas comprises CO.
Claim 24
Dependent Claim
13 words
The method of claim 15 wherein said molecular gas comprises H 2 .
Claim 25
Dependent Claim
33 words
The method of claim 1 wherein said step of irradiating said molecular gas comprises: directing said first and second coherent, variable excitation signals in colinear beams; aligning said waveguide with said colinear beams.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |