US3893771A
Expired / Lapsed
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Laser absorption spectroscopy
Assignee: Diax Corp
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Filing: 1974-08-22
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Granted: 1975-07-08
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Expires: 1994-08-22
Abstract
Abstract In laser absorption spectroscopy, an absorption sample cell containing the sample under analysis, is interposed within the optical cavity of a laser. In this manner, the laser beam power available for application to the sample is increased by a substantial factor, for example by 10 or 100 for a given input power to the laser. In addition, the number of usable laser lines of a tunable laser source is substantially increased, for example by 10 or 100 as contrasted with a laser absorption spectrometer wherein the sample is located outside of the laser cavity.
Inventors
- 👤 William E Bell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:10
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/31; G01N21/39; G01N21/1702; G01N2021/1704
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
97 words
In a laser absorption spectrometer: means for defining an optical resonator; means for producing a laser beam of coherent radiation within said optical resonator; means for interposing a sample medium to be analyzed in said laser beam within said optical resonator for absorbing coherent radiation from said beam and for converting said absorbed coherent radiation of the beam into a second form of energy; and means coupled in energy exchanging relation with the sample medium for detecting said second form of energy resulting from absorption of energy, if any, by said sample medium from said laser beam.
Claim 2
Dependent Claim
97 words
In a laser absorption spectrometer: means for defining an optical resonator; means for producing a laser beam of coherent radiation within said optical resonator; means for interposing a sample medium to be analyzed in said laser beam within said optical resonator for absorbing coherent radiation from said beam and for converting said absorbed coherent radiation of the beam into a second form of energy; and means coupled in energy exchanging relation with the sample medium for detecting said second form of energy resulting from absorption of energy, if any, by said sample medium from said laser beam.
Claim 3
Dependent Claim
66 words
The apparatus of claim 1 wherein said means for producing a laser beam within said optical resonator includes, means for disposing a gain medium within said optical resonator, said gain medium being capable of providing gain at resonant optical wavelengths of said optical resonator means, and means for exciting coherent stimulated emission of radiation from said gain medium at a resonant wavelength of said optical resonator.
Claim 4
Dependent Claim
27 words
The apparatus of claim 1 wherein the laser beam of coherent radiation is at an infrared wavelength and said optical resonator is resonant at said infrared wavelength.
Claim 5
Dependent Claim
19 words
The apparatus of claim 1 including, means for varying the wavelength of the coherent radiation of said laser beam.
Claim 6
Dependent Claim
15 words
The apparatus of claim 1 including, means for modulating the intensity of said laser beam.
Claim 7
Dependent Claim
34 words
The apparatus of claim 5 including, means for synchronously detecting the absorption of energy by the sample medium from said beam as a function of the modulation of the intensity of said laser beam.
Claim 8
Dependent Claim
54 words
The apparatus of claim 1 wherein the sample medium to be analyzed is a fluid and said detector means includes, acoustic detector means disposed in acoustic wave energy exchanging relation with the sample medium for detecting acoustic waves generated by the absorption of laser beam energy in the gaseous sample from the laser beam.
Claim 9
Dependent Claim
35 words
The apparatus of claim 1 including, means within said laser cavity for directing a portion of the laser beam energy into a detector to derive an output proportional to the energy of the laser beam.
Claim 10
Dependent Claim
18 words
The apparatus of claim 8 wherein said laser beam portion directing means comprises a skewed Brewster angle window.
Claim 11
Dependent Claim
103 words
In a method of laser absorption spectroscopy the steps of: exciting an optical resonator with a laser beam to produce a laser beam of coherent radiation within said optical resonator; interposing a sample medium to be analyzed in said laser beam within said optical resonator for absorbing coherent radiation from said beam and for converting said absorbed coherent radiation of the beam into a second form of energy; and coupling a detector in energy exchanging relation with the sample medium for detecting said second form of energy resulting from the absorption of energy, if any, by said sample medium from said laser beam.
Claim 12
Dependent Claim
103 words
In a method of laser absorption spectroscopy the steps of: exciting an optical resonator with a laser beam to produce a laser beam of coherent radiation within said optical resonator; interposing a sample medium to be analyzed in said laser beam within said optical resonator for absorbing coherent radiation from said beam and for converting said absorbed coherent radiation of the beam into a second form of energy; and coupling a detector in energy exchanging relation with the sample medium for detecting said second form of energy resulting from the absorption of energy, if any, by said sample medium from said laser beam.
Claim 13
Dependent Claim
29 words
The method of claim 10 including the step of exciting coherent stimulated emission of radiation from a laser gain medium within said optical resonator to provide the laser beam.
Claim 14
Dependent Claim
29 words
The method of claim 11 wherein the step of exciting coherent stimulated emission of radiation comprises the step of exciting coherent stimulated emission of radiation at an infrared wavelength.
Claim 15
Dependent Claim
20 words
The method of claim 12 including the step of varying the wavelength of the coherent radiation of said laser beam.
Claim 16
Dependent Claim
16 words
The method of claim 10 including the step of modulating the intensity of said laser beam.
Claim 17
Dependent Claim
35 words
The method of claim 14 including the step of detecting the absorption of energy from said laser beam by the sample medium as a function of the modulation of the intensity of said laser beam.
Claim 18
Dependent Claim
45 words
The method of claim 10 wherein the sample medium to be analyzed is a fluid and the step of detecting the absorption of energy includes, detecting the acoustic wave energy generated by the absorption of infrared energy in the gaseous sample from the laser beam.
Claim 19
Dependent Claim
43 words
The method of claim 10 including the step of diverting a portion of the laser beam energy from within the optical resonator and intermediate the length of the beam path to a detector to derive an output proportional to the laser beam power.
Claim 20
Dependent Claim
34 words
The method of claim 17 wherein the step of diverting a portion of the laser beam comprises, reflecting a portion of the laser beam off of a Brewster angle window inside said optical resonator.
References Cited (Backward Citations)
US3322026A
Cited
US3405370A
Cited
US3659452A
Cited
US3732017A
Cited
US3793579A
Cited
US3820901A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |