US4385388A
Expired / Lapsed
US
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Light referencing method
Assignee: University of Oregon
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Filing: 1981-04-27
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Granted: 1983-05-24
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Expires: 2001-04-27
Abstract
Abstract A method for referencing the beam wavelength of a tunable laser with a known spectral line wavelength of a free transition metal atom. A voltage is placed across a pair of electrodes in a cell containing vapor of an organometallic compound of that metal. The vapor is irradiated with a pulse of focused laser light having an average flux density at which electronic transitions of the free transition metal atom are wavelength dependent. The vapor undergoes photodissociation to form free metal atoms. The wavelength of the focused laser light is adjusted until peak current flow across the two electrodes is observed, evidencing photoionization of the free metal atoms proceeding through an excited state corresponding to the referencing wavelength.
Inventors
- 👤 Paul C. Engelking
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:37
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/0014
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
145 words
A method of referencing the beam wavelength of a tunable laser with a known spectral line wavelength of a free transition metal atom, said method comprising forming in an irradiation zone a vapor of a volatile organometallic compound containing said metal atom, applying a voltage across a pair of electrodes in such zone, irradiating such zone with a beam of laser light having an average power flux in the zone at which electronic transitions of the free metal atom are wavelength-dependent, by said irradiating, producing dissociation of the vapor-phase compound to form free metal atoms, monitoring the current flow between the electrodes, and adjusting the wavelength of the laser light to reach correspondence of the light wavelength and spectral line wavelength, such producing multiphoton ionization of the metal atoms, with the atoms proceeding through an excited state, as evidenced by a peaking of current flow.
Claim 2
Independent Claim
145 words
A method of referencing the beam wavelength of a tunable laser with a known spectral line wavelength of a free transition metal atom, said method comprising forming in an irradiation zone a vapor of a volatile organometallic compound containing said metal atom, applying a voltage across a pair of electrodes in such zone, irradiating such zone with a beam of laser light having an average power flux in the zone at which electronic transitions of the free metal atom are wavelength-dependent, by said irradiating, producing dissociation of the vapor-phase compound to form free metal atoms, monitoring the current flow between the electrodes, and adjusting the wavelength of the laser light to reach correspondence of the light wavelength and spectral line wavelength, such producing multiphoton ionization of the metal atoms, with the atoms proceeding through an excited state, as evidenced by a peaking of current flow.
Claim 3
Dependent Claim
14 words
The method of claim 1, wherein such wavelength is in the ultraviolet light region.
Claim 4
Dependent Claim
35 words
The method of claim 1, wherein the light beam is composed of pulses of light, each pulse having an average photon flux density in such zone between about 10 and 200 megawatts per square centimeter.
Claim 5
Dependent Claim
28 words
The method of claim 1, wherein the organometallic compound contains a transition metal and at least one from the group consisting of carbonyl, butadiene, cyclopentadiene, benzene and cyclooctatetraene.
Claim 6
Dependent Claim
13 words
The method of claim 4, wherein said organometallic compound contains iron and cyclopentadiene.
Claim 7
Independent Claim
201 words
A method of referencing the beam wavelength of a tunable laser with a known single-photon excitation spectral line wavelength in a free transition metal atom, where the combined energy of two photons having that spectral line wavelength is less than the ionization potential of the free metal atom, said method comprising forming in an enclosed irradiation zone, a vapor of a volatile organometallic compound containing that metal atom, applying a voltage between a pair of electrodes in such zone, irradiating such zone with pulses of laser light having an average photon flux density in the zone at which substantially only one-photon electronic transitions in the metal atom occur, by said irradiating, producing dissociation of the vapor-phase compound to form free metal atoms, where the duration of the beam pulse is selected in relation to the vapor pressure of the organometallic compound to insure free metal atom collisions during a pulse, measuring the current flow between the electrodes, and adjusting the wavelength of the laser light pulses to reach correspondence of the light wavelength and spectral line wavelength, such producing multiphoton ionization of the metal atoms, with the atoms proceeding through an excited state, as evidenced by a peaking of current flow.
Claim 8
Independent Claim
201 words
A method of referencing the beam wavelength of a tunable laser with a known single-photon excitation spectral line wavelength in a free transition metal atom, where the combined energy of two photons having that spectral line wavelength is less than the ionization potential of the free metal atom, said method comprising forming in an enclosed irradiation zone, a vapor of a volatile organometallic compound containing that metal atom, applying a voltage between a pair of electrodes in such zone, irradiating such zone with pulses of laser light having an average photon flux density in the zone at which substantially only one-photon electronic transitions in the metal atom occur, by said irradiating, producing dissociation of the vapor-phase compound to form free metal atoms, where the duration of the beam pulse is selected in relation to the vapor pressure of the organometallic compound to insure free metal atom collisions during a pulse, measuring the current flow between the electrodes, and adjusting the wavelength of the laser light pulses to reach correspondence of the light wavelength and spectral line wavelength, such producing multiphoton ionization of the metal atoms, with the atoms proceeding through an excited state, as evidenced by a peaking of current flow.
Claim 9
Dependent Claim
14 words
The method of claim 6, wherein such wavelength is in the ultraviolet light region.
Claim 10
Dependent Claim
25 words
The method of claim 6, wherein the pulse average photon flux density in such zone is between about 10 and 200 megawatts per square centimeter.
Claim 11
Dependent Claim
29 words
The method of claim 6, wherein the organometallic compound includes a transition metal atom and at least one from the group consisting of carbonyl, butadiene, cyclopentadiene, benzene and cyclooctatetraene.
Claim 12
Dependent Claim
12 words
The method of claim 6, wherein the compound contains iron and cyclopentadiene.
References Cited (Backward Citations)
US3613026A
Cited
US3720877A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-23 | 1986-11-22 | 1987-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-23 | 1990-11-22 | 1991-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-23 | 1994-11-22 | 1995-05-24 | $7700.00 | Window Closed / Lapsed |