US3782828A
Expired / Lapsed
US
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Picosecond spectrometer using picosecond continuum
Assignee: Verizon Laboratories Inc
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Filing: 1972-03-09
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Granted: 1974-01-01
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Expires: 1992-03-09
Abstract
Abstract Spectroscopic investigation of samples by a relatively large interval spectral continuum (e.g., 4000-8000 A) pulses as short as a few picoseconds are described. The continuum is generated by non-linear interaction effects (such as self-phase modulation) in a material subject to extremely high power monochromatic radiation as may be obtained from a mode-locked solid (glass rod) laser, the flux density being further increased by optically concentrating the laser beam. The effective flux density is further increased by self-focussing within the material. A modelocked laser generating 1.06 micron (10,600 A) pulses of about 4 picosecond duration, which may be converted to 5,300 A pulses of similar duration by a KDP crystal has been successfully used as the source. By exposing the sample to both the continuum and intense monochromatic pulse, inverse Raman (absorption) effects have been observed at both known and previously unknown Raman lines. Other spectroscopic observations may be made at picosecond time scales, including observation of phenomenon in which the sample is exposed to a spectral continuum pulse and a monochromatic pulse (each of a few picoseconds duration) with any desired time lag in either pulse relative to the other.
Inventors
- 👤 R Alfano
- 👤 S Shapiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:13
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/2889
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
122 words
A spectroscopic analysis technique of substantially improved time resolution comprising the steps of generating a high power intensity pulse of optical energy formed of a primary monochromatic pulse segment and a secondary waverelated pulse segment, with the pulse having a duration measured in the order of picoseconds or less and a pulse power intensity sufficiently high to enable generation of a selfphase modulated pulse of optical energy; directing the high power pulse with its primary and secondary segments onto a medium selected to respond with a self-phase modulated pulse of optical energy having a wide frequency spectrum; impinging the self-phase modulated pulse on a sample material to be analyzed; and measuring the resulting radiation from the sample for a spectroscopic characteristic thereof.
Claim 2
Dependent Claim
122 words
A spectroscopic analysis technique of substantially improved time resolution comprising the steps of generating a high power intensity pulse of optical energy formed of a primary monochromatic pulse segment and a secondary waverelated pulse segment, with the pulse having a duration measured in the order of picoseconds or less and a pulse power intensity sufficiently high to enable generation of a selfphase modulated pulse of optical energy; directing the high power pulse with its primary and secondary segments onto a medium selected to respond with a self-phase modulated pulse of optical energy having a wide frequency spectrum; impinging the self-phase modulated pulse on a sample material to be analyzed; and measuring the resulting radiation from the sample for a spectroscopic characteristic thereof.
Claim 3
Dependent Claim
91 words
The spectroscopic analysis technique as claimed in claim 1 wherein the high power pulse genErating step further includes generating the primary segment with a high power pulse of optical energy formed of substantially monochromatic energy and having a pulse duration measured in the order of picoseconds or less with a pulse power intensity sufficiently high to enable a generation of a self-phase modulated pulse of electromagnetic energy; directing the high power pulse at a material selected to produce the secondary segment in the form of a harmonic of the primary segment.
Claim 4
Dependent Claim
70 words
The spectroscopic analysis technique as claimed in claim 1 and further including the steps of substantially separating the intense primary pulse segment and the self-phase modulated pulse from one another; delaying the primary pulse segment relative to the self-phase modulated pulse segment a preselected time; and directing the relatively delayed optical primary pulse and the wide frequency spectrum self-phase modulated pulse onto the sample material for the time-dependent spectroscopic analysis.
Claim 5
Dependent Claim
45 words
The spectroscopic analysis technique as claimed in claim 3 and further including the step of reducing the intensity of the primary pulse segment to a level selected to enable spectroscopic comparison between the primary pulse radiation and wide frequency spectrum radiation from the sample material.
Claim 6
Dependent Claim
66 words
The spectroscopic analysis technique as claimed in claim 3 wherein the delaying step further includes delaying the wide frequency spectrum pulse behind in time to the primary pulse segment, and further including the steps of directing the primary pulse segment at a sample material to simulate said material to an activity level sufficient to produce scattering of the delayed wide frequency spectrum pulse for spectroscopic analysis.
Claim 7
Dependent Claim
42 words
The spectroscopic analysis technique as claimed in claim 3 wherein the separating step further includes directing the primary high power pulse segment and the secondary wave-related pulse segment onto a medium of extended length selected to enable a dispersion of the segments.
Claim 8
Dependent Claim
47 words
The spectroscopic analysis technique as claimed in claim 1 wherein the directing step further includes selecting the intensities of the primary pulse segment and the secondary pulse segment to a level for producing a wide frequency spectrum pulse having a continuum extending across the visible light range.
Claim 9
Dependent Claim
32 words
The spectroscopic analysis technique as claimed in claim 7 wherein the medium is chosen to produce a self-phase modulated spectrum continuum of a range from about 2,900 Angstroms to about 8,000 Angstroms.
Claim 10
Dependent Claim
101 words
A spectrometer for performing spectroscopic analysis of a sample with substantially improved time resolution comprising: means for producing an optical beam formed of a high power intensity pulse of electromagnetic radiation with a time duration of the order of picoseconds or less, said high power pulse being formed of a substantially monochromatic primary pulse segment and a secondary wave related pulse segment; means responsive to the primary and secondary pulse segments for producing a self-phase modulated optical beam pulse having a wide frequency spectrum; and means for directing the self-phase modulated optical beam pulse at the sample for spectroscopic analysis thereof.
Claim 11
Dependent Claim
101 words
A spectrometer for performing spectroscopic analysis of a sample with substantially improved time resolution comprising: means for producing an optical beam formed of a high power intensity pulse of electromagnetic radiation with a time duration of the order of picoseconds or less, said high power pulse being formed of a substantially monochromatic primary pulse segment and a secondary wave related pulse segment; means responsive to the primary and secondary pulse segments for producing a self-phase modulated optical beam pulse having a wide frequency spectrum; and means for directing the self-phase modulated optical beam pulse at the sample for spectroscopic analysis thereof.
Claim 12
Dependent Claim
55 words
The spectrometer as claimed in claim 9 wherein said high power intensity pulse producing means further includes a mode-locked laser to produce the high power intensity pulse; means responsive to the output from the mode-locked laser for producing a harmonic thereof, the laser output and said harmonic respectively representing said primary and secondary pulse segments.
Claim 13
Dependent Claim
80 words
The spectrometer as claimed in claim 9 and further including means for separating the primary pulse segment from the wide frequency optical beam pulse from each other; means for relatively delaying the separated primary pulse segment and the wide frequency optical beam pulse, a predetermined amount of time; and means for directing the relatively delayed primary pulse segment and the wide frequency optical beam pulse onto the sample at a common place thereon for spectroscopic time-dependent analysis of the sample.
Claim 14
Dependent Claim
32 words
The spectrometer as claimed in claim 11 and further including means for reducing the intensity of the primary pulse segment by an amount selected to enable comparison of radiations from the sample.
Claim 15
Dependent Claim
52 words
An improved spectrometer according to claim 12, in which: said means for generating said high power substantially monochromatic pulse also comprises a harmonic frequency generating material receiving the extremely high power monochromatic pulse produced by said mode-locked laser, so as to generate therefrom a second monochromatic pulse at a harmonically related frequency.
Claim 16
Dependent Claim
28 words
An improved spectrometer according to claim 10, wherein the self-phase modulated optical beam pulse producing means produces a pulse having a frequency spectrum extending across the visible region.
Claim 17
Dependent Claim
142 words
A spectrometer for performing spectroscopic analysis of a sample with substantially improved time resolution comprising a mode-locked laser to produce a high power intensity substantially monochromatic optical pulse of less than about ten picoseconds duration; means responsive to the optical pulse for producing a substantially monochromatic harmonic thereof; a material positioned in the path of the monochromatic optical pulse and the harmonic thereof, said material being selected to respond to said high power intensity pulse to convert at least a moderate part of said pulse into a substantially continuous wide spectrum pulse; delay means positioned in the optical path between said material for converting part of the high power intensity pulse and the sample; said delay means being adjustable to control the relative time arrival of the wide spectrum pulse and the high intensity monochromatic pulse at the sample for spectroscopic analysis.
Claim 18
Dependent Claim
142 words
A spectrometer for performing spectroscopic analysis of a sample with substantially improved time resolution comprising a mode-locked laser to produce a high power intensity substantially monochromatic optical pulse of less than about ten picoseconds duration; means responsive to the optical pulse for producing a substantially monochromatic harmonic thereof; a material positioned in the path of the monochromatic optical pulse and the harmonic thereof, said material being selected to respond to said high power intensity pulse to convert at least a moderate part of said pulse into a substantially continuous wide spectrum pulse; delay means positioned in the optical path between said material for converting part of the high power intensity pulse and the sample; said delay means being adjustable to control the relative time arrival of the wide spectrum pulse and the high intensity monochromatic pulse at the sample for spectroscopic analysis.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |