US4194170A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shifting of infrared radiation using rotational raman resonances in diatomic molecular gases
Assignee: United States Department of Energy
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Filing: 1978-11-13
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Granted: 1980-03-18
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Expires: 1998-11-13
Abstract
Abstract A device for shifting the frequency of infrared radiation from a CO 2 laser by stimulated Raman scattering in either H 2 or D 2 . The device of the preferred embodiment comprises an H 2 Raman laser having dichroic mirrors which are reflective for 16 μm radiation and transmittive for 10 μm, disposed at opposite ends of an interaction cell. The interaction cell contains a diatomic molecular gas, e.g., H 2 , D 2 , T 2 , HD, HT, DT and a capillary waveguide disposed within the cell. A liquid nitrogen jacket is provided around the capillary waveguide for the purpose of cooling. In another embodiment the input CO 2 radiation is circularly polarized using a Fresnel rhomb λ/4 plate and applied to an interaction cell of much longer length for single pass operation.
Inventors
- 👤 Norman A. Kurnit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:28
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/30; H01S3/305
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
104 words
A Raman laser for frequency shifting infrared radiation comprising: an infrared radiation source for producing said infrared radiation; an interaction cell containing a diatomic molecular gas; a restrahl reflective capillary waveguide disposed within said interaction cell; dichroic means disposed at each end of said interaction cell for primarily reflecting frequency shifted radiation and primarily transmitting said infrared radiation from said infrared radiation source; whereby said capillary waveguide increased focal interaction length between said infrared radiation from said infrared radiation source and said diatomic molecular gas to overcome losses and produce stimulated Raman scattered frequency shifted radiation from rotational transitions in said diatomic molecular gas.
Claim 2
Dependent Claim
104 words
A Raman laser for frequency shifting infrared radiation comprising: an infrared radiation source for producing said infrared radiation; an interaction cell containing a diatomic molecular gas; a restrahl reflective capillary waveguide disposed within said interaction cell; dichroic means disposed at each end of said interaction cell for primarily reflecting frequency shifted radiation and primarily transmitting said infrared radiation from said infrared radiation source; whereby said capillary waveguide increased focal interaction length between said infrared radiation from said infrared radiation source and said diatomic molecular gas to overcome losses and produce stimulated Raman scattered frequency shifted radiation from rotational transitions in said diatomic molecular gas.
Claim 3
Dependent Claim
53 words
The laser of claim 1 further comprising: a spatial filter aligned with said infrared radiation source; and means for focusing said infrared radiation from said infrared radiation source, said means for focusing having a short focal length to maximize radiation intensity within said capillary waveguide without causing window damage to said dichroic means.
Claim 4
Dependent Claim
18 words
The laser of claim 1 wherein said capillary comprises a MgO capillary having restrahl reflectivity to reduce losses.
Claim 5
Dependent Claim
21 words
The laser of claim 1 wherein said capillary comprises an Al 2 O 3 capillary having restrahl reflectivity to reduce losses.
Claim 6
Dependent Claim
18 words
The laser of claim 1 wherein said capillary comprises a BeO capillary having restrahl reflectivity to reduce losses.
Claim 7
Dependent Claim
23 words
The laser of claim 1 further comprising means for cryogenically cooling said capillary to maintain ground state population of said diatomic molecular gas.
Claim 8
Dependent Claim
17 words
The laser of claim 1 wherein said infrared radiation source comprises a variable frequency CO 2 laser.
Claim 9
Dependent Claim
18 words
The laser of claim 2 wherein said capillary comprises a MgO capillary having restrahl reflectivity to reduce losses.
Claim 10
Dependent Claim
21 words
The laser of claim 2 wherein said capillary comprises an Al 2 O 3 capillary having restrahl reflectivity to reduce losses.
Claim 11
Dependent Claim
18 words
The laser of claim 2 wherein said capillary comprises a BeO capillary having restrahl reflectivity to reduce losses.
Claim 12
Dependent Claim
23 words
The laser of claim 2 further comprising means for cryogenically cooling said capillary to maintain ground state population of said diatomic molecular gas.
Claim 13
Dependent Claim
17 words
The laser of claim 2 wherein said infrared radiation source comprises a variable frequency CO 2 laser.
Claim 14
Dependent Claim
13 words
The laser of claim 1 wherein said diatomic molecule comprises H 2 .
Claim 15
Dependent Claim
13 words
The laser of claim 1 werein said diatomic molecule comprises D 2 .
Claim 16
Dependent Claim
13 words
The laser of claim 1 wherein said diatomic molecule comprises T 2 .
Claim 17
Dependent Claim
11 words
The laser of claim 1 wherein said diatomic molecule comprises HD.
Claim 18
Dependent Claim
11 words
The laser of claim 1 wherein said diatomic molecule comprises HT.
Claim 19
Dependent Claim
11 words
The laser of claim 1 wherein said diatomic molecule comprises DT.
Claim 20
Dependent Claim
17 words
The laser of claim 1 wherein said infrared radiation source comprises a multiple frequency infrared radiation source.
Claim 21
Dependent Claim
16 words
The laser of claim 1 wherein said infrared radiation source comprises a modelocked infrared radiation source.
Claim 22
Dependent Claim
26 words
The laser of claim 1 further comprising means for circularly polarizing said infrared radiation to increase Raman gain and reduce anti-Stokes generation within said capillary waveguide.
Claim 23
Independent Claim
116 words
A device for producing stimulated Raman scattering from rotational transitions in a diatomic molecular gas to frequency shift infrared radiation comprising: an infrared source for producing said infrared radiation; an interaction cell containing said diatomic molecular gas; restrahl reflective capillary waveguide means disposed within said interaction cell to increase focal interaction length and reduce losses; means for circularly polarizing said infrared radiation to increase Raman gain and reduce anti-Stokes generation within said capillary waveguide; whereby said focal interaction length is increased sufficiently within said capillary waveguide to overcome losses and produce stimulated Raman scattered frequency shifted radiation from rotational transitions in said molecular gas in a single pass of said infrared radiation through said capillary waveguide.
Claim 24
Independent Claim
116 words
A device for producing stimulated Raman scattering from rotational transitions in a diatomic molecular gas to frequency shift infrared radiation comprising: an infrared source for producing said infrared radiation; an interaction cell containing said diatomic molecular gas; restrahl reflective capillary waveguide means disposed within said interaction cell to increase focal interaction length and reduce losses; means for circularly polarizing said infrared radiation to increase Raman gain and reduce anti-Stokes generation within said capillary waveguide; whereby said focal interaction length is increased sufficiently within said capillary waveguide to overcome losses and produce stimulated Raman scattered frequency shifted radiation from rotational transitions in said molecular gas in a single pass of said infrared radiation through said capillary waveguide.
Claim 25
Dependent Claim
30 words
The device of claim 22 further comprising means for focusing said infrared radiation at one end of said capillary waveguide at an intensity sufficient to produce frequency shifted infrared radiation.
Claim 26
Dependent Claim
25 words
The device of claim 22 further comprising means for cryogenically cooling said capillary waveguide means to maintain ground state population in said diatomic molecular gas.
Claim 27
Dependent Claim
25 words
The device of claim 23 further comprising means for cryogenically cooling said capillary waveguide means to maintain ground state population in said diatomic molecular gas.
Claim 28
Dependent Claim
20 words
The device of claim 22 wherein said capillary waveguide means comprises a MgO capillary having restrahl reflectivity to reduce losses.
Claim 29
Dependent Claim
23 words
The device of claim 22 wherein said capillary waveguide means comprises an Al 2 O 3 capillary having restrahl reflectivity to reduce losses.
Claim 30
Dependent Claim
20 words
The device of claim 22 wherein said capillary waveguide means comprises a BeO capillary having restrahl reflectivity to reduce losses.
Claim 31
Dependent Claim
21 words
The device of claim 22 further comprising spatial filter means for eliminating hotspots in the spatial intensity of said infrared radiation.
Claim 32
Dependent Claim
14 words
The device of claim 22 wherein said diatomic molecular gas comprises H 2 .
Claim 33
Dependent Claim
14 words
The device of claim 22 wherein said diatomic molecular gas comprises D 2 .
Claim 34
Dependent Claim
14 words
The device of claim 22 wherein said diatomic molecular gas comprises T 2 .
Claim 35
Dependent Claim
12 words
The device of claim 22 wherein said diatomic molecular gas comprises HD.
Claim 36
Dependent Claim
12 words
The device of claim 22 wherein said diatomic molecular gas comprises HT.
Claim 37
Dependent Claim
12 words
The device of claim 22 wherein said diatomic molecular gas comprises DT.
Claim 38
Dependent Claim
15 words
The device of claim 22 wherein said infrared source comprises a tunable CO 2 laser.
Claim 39
Dependent Claim
15 words
The device of claim 22 wherein said infrared source comprises a N 2 O laser.
Claim 40
Dependent Claim
14 words
The device of claim 22 wherein said infrared source comprises a CS 2 laser.
Claim 41
Dependent Claim
16 words
The device of claim 22 wherein said infrared source comprises a multiple frequency CO 2 laser.
Claim 42
Dependent Claim
16 words
The device of claim 22 wherein said infrared source comprises a multiple frequency infrared radiation source.
References Cited (Backward Citations)
US3655993A
Cited
US3705992A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-03-18 | 1983-09-17 | 1984-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-03-18 | 1987-09-17 | 1988-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-03-18 | 1991-09-17 | 1992-03-18 | $7700.00 | Window Closed / Lapsed |