US4197009A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photoacoustic Raman spectroscopy
Assignee: Honeywell International Inc
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Filing: 1978-05-26
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Granted: 1980-04-08
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Expires: 1998-05-26
Abstract
Abstract A method and apparatus for spectroscopic material anaylsis are provided. Two coherent beams 15, 17 of monochromatic radiation are directed through a sample of material. A tuning mechanism 14 adjusts the frequency difference between the radiation beams 15, 17 to equal substantially the vibrational frequency of a preselected constituent of the material. Molecular energy of a preselected constituent of the material is increased, thereby producing a detectable signal 22 in the form of a pressure wave. The signal is received by a detecting mechanism 24 which indicates the magnitude thereof.
Inventors
- 👤 Michael J. Berry
- 👤 Joseph J. Barrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:55
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/1702; G01J; G01J3/00; G01J3/28; G01J3/44; G01N2021/1704
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
98 words
Apparatus for analyzing material, comprising: a. radiation source means (12) for generating two coherent beams (15, 17) of monochromatic light; b. tuning means (14) for adjusting the frequency difference between said beams (15, 17) of radiation to equal substantially the vibrational frequency of a preselected constituent of said material; c. projecting means (16) for directing said beams of light through said material to increase molecular energy of a preselected species of said material and thereby produce a detectable signal (22) in the form of a pressure wave; d. detecting means (24) for indicating the magnitude of said signal.
Claim 2
Dependent Claim
98 words
Apparatus for analyzing material, comprising: a. radiation source means (12) for generating two coherent beams (15, 17) of monochromatic light; b. tuning means (14) for adjusting the frequency difference between said beams (15, 17) of radiation to equal substantially the vibrational frequency of a preselected constituent of said material; c. projecting means (16) for directing said beams of light through said material to increase molecular energy of a preselected species of said material and thereby produce a detectable signal (22) in the form of a pressure wave; d. detecting means (24) for indicating the magnitude of said signal.
Claim 3
Dependent Claim
25 words
Apparatus as recited in claim 1, wherein said tuning means (14) is adjusted to selectively populate a higher energy level of said preselected molecular species.
Claim 4
Dependent Claim
25 words
Apparatus as recited in claim 1, wherein said projecting means (16) is adjusted to effect spatial and temporal overlap between said radiation beams (15, 17).
Claim 5
Dependent Claim
55 words
Apparatus as recited in claim 1, wherein said radiation source means (12) comprises a dye laser (24) including a dye cell (28) containing a dye material, means for exciting said dye (26) and a laser cavity comprised of an optical element (32) and a partially transmitting output mirror (30) for generating and transmitting laser radiation.
Claim 6
Dependent Claim
26 words
Apparatus as recited in claim 4, wherein said dye material emits radiation upon being excited, said radiation having frequencies within the transparency range of said material.
Claim 7
Dependent Claim
33 words
Apparatus as recited in claim 1, wherein said tuning means comprises beam splitting means for separating said radiation into a pair of radiation beams, and a pair of diffraction gratings mounted in autocollimation.
Claim 8
Independent Claim
76 words
A method for spectroscopically analyzing material comprising the steps of: a. generating two coherent beams (15, 17) of monochromatic radiation; b. adjusting the frequency difference between the beams of radiation (15, 17) to equal substantially the vibrational frequency of a preselected constituent of said material; c. directing the beams of radiation through the material to produce a detectable signal (22) in the form of a pressure wave; and d. indicating the intensity of said signal (22).
Claim 9
Independent Claim
76 words
A method for spectroscopically analyzing material comprising the steps of: a. generating two coherent beams (15, 17) of monochromatic radiation; b. adjusting the frequency difference between the beams of radiation (15, 17) to equal substantially the vibrational frequency of a preselected constituent of said material; c. directing the beams of radiation through the material to produce a detectable signal (22) in the form of a pressure wave; and d. indicating the intensity of said signal (22).
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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |