US4798467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heterodyne laser instantaneous frequency measurement system
Assignee: United States Department of Energy
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Filing: 1986-09-24
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Granted: 1989-01-17
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Expires: 2006-09-24
Abstract
Abstract A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.
Inventors
- 👤 Richard W. Wyeth
- 👤 Michael A. Johnson
- 👤 Michael A. Globig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:58
CPC Classifications
G; G01; G01J; G01J9/00; G01J9/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A laser beam frequency diagnostic system comprising: a first pulsed laser for generating a first short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, a second reference laser for generating a second laser beam having a predetermined frequency, means for heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determining the derivative of said relative phase versus time.
Claim 2
Dependent Claim
129 words
A laser beam frequency diagnostic system comprising: a first pulsed laser for generating a first short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, a second reference laser for generating a second laser beam having a predetermined frequency, means for heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determining the derivative of said relative phase versus time.
Claim 3
Dependent Claim
18 words
A system as in claim 1 wherein said second reference laser is a continuous wave (CW) reference laser.
Claim 4
Dependent Claim
15 words
A system as in claim 1 wherein said second reference laser is a pulsed laser.
Claim 5
Dependent Claim
19 words
A system as in claim 1 including mixer means for converting said beat signal down to a lower frequency.
Claim 6
Dependent Claim
20 words
A system as in claim 1 including means for time multiplexing said beat signal and said pulsed laser intensity signal.
Claim 7
Dependent Claim
133 words
A laser beam frequency diagnostic system comprising: a first pulsed laser for generating a first short time duaration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, a second continuous wave (CW) reference laser for generating a second laser beam having a predetermined frequency, means for heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, and means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determining the derivative of said relative phase versus time.
Claim 8
Dependent Claim
133 words
A laser beam frequency diagnostic system comprising: a first pulsed laser for generating a first short time duaration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, a second continuous wave (CW) reference laser for generating a second laser beam having a predetermined frequency, means for heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, and means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determining the derivative of said relative phase versus time.
Claim 9
Dependent Claim
126 words
A laser beam frequency diagnostic system for determining the instantaneous frequency of a short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, said system comprising: a continuous wave (CW) reference laser for generating a CW laser beam having a predetermined frequency, means for heterodyning said pulsed laser beam and said CW laser beam to form a beat signal representative of the difference between said first and second frequencies, means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determing the derivative of said relative phase versus time.
Claim 10
Dependent Claim
126 words
A laser beam frequency diagnostic system for determining the instantaneous frequency of a short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, said system comprising: a continuous wave (CW) reference laser for generating a CW laser beam having a predetermined frequency, means for heterodyning said pulsed laser beam and said CW laser beam to form a beat signal representative of the difference between said first and second frequencies, means for processing said beat signal to determine the instantaneous frequency of said first laser beam, means for normalizing said beat signal, means for determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and means for determing the derivative of said relative phase versus time.
Claim 11
Dependent Claim
120 words
In a laser beam frequency diagnostic system, the method comprising the steps of: generating a first short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, generating a second continuous laser beam having a predetermined frequency, heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, processing said beat signal to determine the instantaneous frequency of said first laser beam, including the steps of normalizing said beat signal, determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and determining the relative of said relative phase versus time.
Claim 12
Dependent Claim
120 words
In a laser beam frequency diagnostic system, the method comprising the steps of: generating a first short time duration pulsed laser beam having a pulse length duration of approximately 10-100 nanoseconds, the instantaneous frequency of which is to be determined, generating a second continuous laser beam having a predetermined frequency, heterodyning said first and second laser beams to form a beat signal representative of the difference between said first and second frequencies, processing said beat signal to determine the instantaneous frequency of said first laser beam, including the steps of normalizing said beat signal, determining the relative phase between said beat signal and an assumed constant frequency average beat signal, and determining the relative of said relative phase versus time.
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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) | 1992-01-17 | 1992-07-18 | 1993-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-17 | 1996-07-18 | 1997-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-17 | 2000-07-18 | 2001-01-17 | $7700.00 | Window Closed / Lapsed |