Patent US1340221A successfully refreshed from Google Patents.
USH15H
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Broadband source of picosecond radiation
Assignee: Nokia Bell Labs
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Filing: 1983-03-28
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Granted: 1986-01-07
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Expires: 2003-03-28
Abstract
Abstract The present invention relates to a means for generating a broadband source of picosecond radiation in the visible and near-infrared spectral regions. In operation, picosecond pulses with wavelength λ are supplied by a laser pump source (10) and injected into the liquid core of a single mode optical fiber (18). A broadband continuum is generated in the liquid core by two mechanisms. Stimulated Raman scattering in the liquid core of the optical fiber shifts the wavelength of the incoming radiation by an amount equal to the energy of the vibrations in the liquid molecules, where with sufficient power, multiple shifts are possible. In addition, the pump radiation and the shifted radiation are broadened by self-phase modulation thereby "filling" the region between the discrete shifted lines. The output radiation from the optical fiber is, therefore, a broadband tunable picosecond pulse source.
Inventors
- 👤 Andrew R. Chraplyvy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 08:20
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/30; H01S3/307
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
219 words
Apparatus for producing broadband pulse radiation comprising an input pump laser picosecond pulse source for providing a sequence of laser pulses at a predetermined wavelength; and optical fiber means coupled to said input laser pulse source wherein said optical fiber means comprises a predetermined diameter D, a first index of a refraction n C , and a core region including a liquid medium of molecules having a predetermined vibrational energy, said liquid medium having a second index of refraction n L , wherein said first and said second indices of refraction satisfy the relation ##EQU2## so that said optical fiber means comprises a single mode optical fiber means, said liquid medium capable of inducing stimulated Raman scattering in said sequence of laser pulses for shifting said sequence of laser pulses to wavelengths related to the predetermined vibrational energy of the molecules , thus forming as a first output of said apparatus a Raman shifted sequence of pulse radiation, said sequence of laser pulses also combining in said core region with said Raman shifted sequence of pulse radiation to produce as a second output of said apparatus a continuum source of radiation at wavelengths other than those associated with said Raman shifted sequence, the combination of said first output and said second output thus being defined as broadband pulse radiation.
Claim 2
Dependent Claim
219 words
Apparatus for producing broadband pulse radiation comprising an input pump laser picosecond pulse source for providing a sequence of laser pulses at a predetermined wavelength; and optical fiber means coupled to said input laser pulse source wherein said optical fiber means comprises a predetermined diameter D, a first index of a refraction n C , and a core region including a liquid medium of molecules having a predetermined vibrational energy, said liquid medium having a second index of refraction n L , wherein said first and said second indices of refraction satisfy the relation ##EQU2## so that said optical fiber means comprises a single mode optical fiber means, said liquid medium capable of inducing stimulated Raman scattering in said sequence of laser pulses for shifting said sequence of laser pulses to wavelengths related to the predetermined vibrational energy of the molecules , thus forming as a first output of said apparatus a Raman shifted sequence of pulse radiation, said sequence of laser pulses also combining in said core region with said Raman shifted sequence of pulse radiation to produce as a second output of said apparatus a continuum source of radiation at wavelengths other than those associated with said Raman shifted sequence, the combination of said first output and said second output thus being defined as broadband pulse radiation.
Claim 3
Dependent Claim
146 words
Apparatus formed in accordance with claim 1 wherein said apparatus further comprises a first mirror located between the input laser pulse source and the optical fiber means, said first mirror being capable of transmitting the sequence of laser pulses provided by said input laser pulse source and reflecting both the Raman shifted sequence of pulses and continuum source of radiation formed in the core region of said optical fiber means; and a second mirror located at the output of said optical fiber means capable of reflecting a first portion of the broadband pulse radiation and transmitting a second portion of said broadband pulse radiation produced by said optical fiber means, the reflected portion of said broadband pulse radiation capable of combining with both the input sequence of laser pulses and the Raman shifted sequence of pulses to maintain a synchronously pumped output of broadband pulse radiation.
Claim 4
Dependent Claim
160 words
Apparatus formed in accordance with claim 1 wherein the optical fiber means comprises a fluid reservoir for containing a fluid medium exhibiting a first index of refraction n C and capable of causing stimulated Raman scattering in the input sequence of laser pulses; a hollow-core optical fiber exhibiting a second index of refraction n L embedded in the fluid reservoir so that the fluid medium fills the core region of said hollow-core optical fiber; an input window disposed on a first surface of said fluid reservoir in a manner whereby said input sequence of laser pulses passes through said input window and propagates through said core region of said hollow-core fiber; and an output window disposed on a second surface of said fluid reservoir in a manner whereby the combination of the Raman shifted sequence of pulse radiation and the continuum source of radiation are capable of passing therethrough as the broadband pulse radiation output of said optical fiber means.
Claim 5
Dependent Claim
52 words
Apparatus formed in accordance with claim 1 wherein the apparatus further comprises a first focusing lens disposed between the input pulse source and the optical fiber means; and a second focusing lens disposed in the path of the output broadband pulse radiation sequence produced as an output of said optical fiber means.
Claim 6
Dependent Claim
20 words
Apparatus formed in accordance with claim 1 wherein the liquid medium comprises 90% CCl 4 and 10% CBrCl 3 .
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-01-06 | 1989-07-08 | 1990-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-06 | 1993-07-08 | 1994-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-06 | 1997-07-08 | 1998-01-07 | $7700.00 | Window Closed / Lapsed |