US3914709A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for lengthening laser output pulse duration
Assignee: Jersey Nuclear Avco Isotopes Inc
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Filing: 1973-05-14
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Granted: 1975-10-21
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Expires: 1993-05-14
Abstract
Abstract Apparatus for use with a laser oscillator having a short duration pulse output with high spectral purity for amplifying and lengthening the pulse output without loss of spectral purity. The apparatus typically includes a laser amplifier and means for applying radiation from the laser oscillator to the amplifier and for reapplying a predetermined portion of the amplifier output regeneratively to the amplifier to maintain it in an amplifying condition for a period several times longer than the duration of the original radiation pulse from the laser oscillator. A timing system is provided for synchronizing the application of laser oscillator radiation to the amplifier coincident with excitation of the amplifier to a lasing condition.
Inventors
- 👤 Charles T Pike
- 👤 Irving Itzken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:14
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/23; H01S3/2358; H01S3/2308
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
108 words
A system for lengthening the duration of laser pulse radiation comprising: means for generating a laser radiation pulse; a laser radiation pulse amplifier for the generated pulse and including means for exciting the laser amplifier to an amplifying condition; the generated pulse from said generating means being directed to said laser amplifier to provide amplified laser radiation as the amplified pulse generated from said laser generating means; means for reapplying a predetermined portion of said amplified laser radiation to said laser amplifier; and means for timing the reapplication of said predetermined portion subsequent to the prior amplified pulse to provide a sequence of amplified laser output radiation pulses.
Claim 2
Independent Claim
108 words
A system for lengthening the duration of laser pulse radiation comprising: means for generating a laser radiation pulse; a laser radiation pulse amplifier for the generated pulse and including means for exciting the laser amplifier to an amplifying condition; the generated pulse from said generating means being directed to said laser amplifier to provide amplified laser radiation as the amplified pulse generated from said laser generating means; means for reapplying a predetermined portion of said amplified laser radiation to said laser amplifier; and means for timing the reapplication of said predetermined portion subsequent to the prior amplified pulse to provide a sequence of amplified laser output radiation pulses.
Claim 3
Dependent Claim
54 words
The system for laser pulse duration lengthening of claim 1 further including means for producing the laser radiation pulse from said generating means and the excitation of said laser amplifier in timed relation to provide amplification of the laser output radiation pulse from said generating means before siad laser amplifier reaches a self-lasing condition.
Claim 4
Dependent Claim
28 words
The system for laser pulse duration lengthening of claim 2 wherein said producing means includes means repeatedly operative for producing the laser radiation pulse and laser amplifier excitation.
Claim 5
Dependent Claim
95 words
The system for laser pulse duration lengthening of claim 1 including: means for dividing laser radiation incident thereon into separate paths and placed to receive the radiation from said generating means and to direct on a first path radiation to said laser amplifier; and means for providing a radiation path for amplified laser radiation from said laser amplifier to said laser radiation splitting means to provide a portion thereof directed toward said laser amplifier on said first path and a second portion directed on a second path as said sequence of laser output radiation pulses.
Claim 6
Dependent Claim
83 words
The system for laser pulse duration lengthening of claim 4 wherein: said laser amplifier includes a ring configuration radiation path; and said radiation dividing means includes a beam splitter positioned to receive amplified laser radiation of said laser amplifier from the ring configuration path on a first angle and to reflect radiation into said ring configuration path on a second angle; said beam splitter being operative to pass a portion of the received amplified laser radiation to provide the sequence of output pulses.
Claim 7
Dependent Claim
90 words
The system for laser pulse duration lengthening of claim 1 further including: a beam splitter receiving radiation from said generating means and applying a substantial portion thereof to said laser amplifier and receiving amplified radiation from said laser amplifier and applying a substantial portion thereof to an output path for said sequence of output pulses; and said reapplying means comprising a partially reflecting mirror returning a portion of the amplified laser radiation to said laser amplifier and directing a further portion of the amplified laser radiation to said beam splitter.
Claim 8
Dependent Claim
42 words
The system for laser pulse duration lengthening of claim 1 wherein said reapplying means includes means for providing said predetermined portion at an amplitude which maintains a generally constant amplitude for the pulses in said sequence of amplified laser output radiation pulses.
Claim 9
Dependent Claim
26 words
The system for laser pulse duration lengthening of claim 7 wherein said predetermined portion is the reciprocal of the net amplification of the amplified laser radiation.
Claim 10
Dependent Claim
18 words
The system for laser pulse duration lengthening of claim 1 wherein said timing means includes an optical delay.
Claim 11
Dependent Claim
21 words
The system for laser pulse duration lengthening of claim 1 wherein said timing means includes a cavity for said laser amplifier.
Claim 12
Dependent Claim
18 words
The system for laser pulse duration lengthening of claim 1 wherein said laser oscillator includes a dye laser.
Claim 13
Dependent Claim
22 words
The system for laser pulse duration lengthening of claim 11 wherein said dye laser is tuned for selective absorption by an isotope.
Claim 14
Dependent Claim
21 words
The system for laser pulse duration lengthening of claim 1 further including a spectrograph for the sequence of amplified radiation pulses.
Claim 15
Dependent Claim
31 words
The system for laser pulse duration lengthening of claim 1 wherein said laser amplifier further includes means for maintaining a narrow bandwidth in the sequence of amplified laser output radation pulses.
Claim 16
Dependent Claim
20 words
The system for laser pulse duration lengthening of claim 14 wherein said means for maintaining bandwidth includes a saturable absorber.
Claim 17
Dependent Claim
27 words
The system for laser pulse duration lengthening of claim 1 further including means for monitoring the spectral content of said sequence of amplified laser output radiation pulses.
Claim 18
Independent Claim
131 words
A system for lengthening the duration of a laser radiation pulse from a laser oscillator comprising: a laser oscillator having in an output radiation pulse a predetermined frequency output and substantially narrow spectral range; a laser radiation amplifier responsive to the output radiation pulse of said laser oscillator to provide an amplified radiatiton output pulse, and including means for exciting the laser amplifier to create an amplifying condition therein for laser radiation; means for reapplying a portion of the amplified radiation output pulse of said laser amplifier back to said laser radiation amplifier for subsequent amplification thereby; and means for timing the reapplication of said portion to provide amplification of said portion directly subsequent to the provision of each pulse of amplified radiation output from which each said portion is taken.
Claim 19
Independent Claim
131 words
A system for lengthening the duration of a laser radiation pulse from a laser oscillator comprising: a laser oscillator having in an output radiation pulse a predetermined frequency output and substantially narrow spectral range; a laser radiation amplifier responsive to the output radiation pulse of said laser oscillator to provide an amplified radiatiton output pulse, and including means for exciting the laser amplifier to create an amplifying condition therein for laser radiation; means for reapplying a portion of the amplified radiation output pulse of said laser amplifier back to said laser radiation amplifier for subsequent amplification thereby; and means for timing the reapplication of said portion to provide amplification of said portion directly subsequent to the provision of each pulse of amplified radiation output from which each said portion is taken.
Claim 20
Dependent Claim
23 words
The system for lengthening the duration of a laser radiation pulse of claim 17 wherein said laser radiation amplifier includes a ring laser.
Claim 21
Dependent Claim
50 words
The system for lengthening the duration of a laser radiation pulse of claim 18 wherein said reapplying means includes a beam splitter which reflects a portion of said amplified radiation output pulse back to said laser amplifier and passes a portion to provide a sequence of amplified radiation output pulses.
Claim 22
Dependent Claim
34 words
The system for lengthening the duration of a laser radiation pulse of claim 17 wherein: said laser amplifier includes an optical cavity; and said reapplying means includes a partially reflecting mirror in said cavity.
Claim 23
Dependent Claim
46 words
The system for lengthening the duration of a laser radiation pulse of claim 17 further including means for energizing said laser oscillator and laser amplifier exciting means in timed relationship to produce amplification of the laser oscillator output radiation pulse generally without loss of spectral purity.
Claim 24
Independent Claim
103 words
A method for lengthening the duration of laser pulse radiation including the steps of: generating a pulse of laser radiation having a radiation spectral purity sufficient to distinguish between isotope absorption lines for a material; amplifying said pulse of laser radiation to provide an amplified pulse; controlling the amplification of said pulse of laser radiation to maintain the spectral purity thereof; reapplying a portion of the amplified pulse for amplification thereby to provide a sequence of amplified pulses; and producing output radiation in response to the sequence of amplified pulses, said sequence having a duration substantially longer than said pulse of laser radiation.
Claim 25
Independent Claim
103 words
A method for lengthening the duration of laser pulse radiation including the steps of: generating a pulse of laser radiation having a radiation spectral purity sufficient to distinguish between isotope absorption lines for a material; amplifying said pulse of laser radiation to provide an amplified pulse; controlling the amplification of said pulse of laser radiation to maintain the spectral purity thereof; reapplying a portion of the amplified pulse for amplification thereby to provide a sequence of amplified pulses; and producing output radiation in response to the sequence of amplified pulses, said sequence having a duration substantially longer than said pulse of laser radiation.
Claim 26
Dependent Claim
25 words
The method of claim 22 wherein said controlling step further includes the step of causing the amplification of said pulse of laser radiation without self-oscillation.
Claim 27
Dependent Claim
28 words
The method of claim 22 wherein said producing step further includes the step of splitting each amplified pulse into said portion for reamplification and into said output radiation.
Claim 28
Dependent Claim
32 words
The method of claim 22 wherein said reapplying step includes timing the amplification of each portion to be directly subsequent to the provision of each amplified pulse from which that portion comes.
References Cited (Backward Citations)
US3646468A
Cited
US3740664A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-10-20 | 1979-04-21 | 1979-10-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-10-20 | 1983-04-21 | 1983-10-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-10-20 | 1987-04-21 | 1987-10-21 | $7700.00 | Window Closed / Lapsed |