US3761185A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Laser light pulse monitoring system
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1970-12-18
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Granted: 1973-09-25
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Expires: 1990-12-18
Abstract
Abstract The light output of a doubly pulsed laser is monitored by converting the two successive light pulses into corresponding electrical pulses and feeding the electrical pulses to a pair of parallel connected circuit channels. A first one of the circuit channels is conditioned to receive the first electrical pulse while a second one of the circuit channels is rendered immune to that pulse. The first electrical pulse charges a capacitor to a voltage proportional to the pulse amplitude and the voltage is displayed on a direct current voltmeter. The second circuit channel is conditioned to receive the second electrical pulse while the first circuit channel is rendered immune to that pulse. The second electrical pulse charges another capacitor to a voltage proportional to the pulse amplitude and the voltage is displayed on another meter. Both voltages are maintained for comparison with one another, after which the circuit channels may be reset to their initial condition for reception of the next set of electrical pulses.
Inventors
- 👤 D Blackwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 14:55
CPC Classifications
G; G01; G01J; G01J1/00; G01J1/42; G01J1/4257
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
277 words
In a system for measuring the relative intensity of first and second rapidly recurring laser light pulses: means responsive to said first laser light pulse for developing a first electrical pulse whose amplitude is a function of the energy of said first laser light pulse; a first signal channel receptive of said first electrical pulse including means for converting said pulse into a corresponding first direct current voltage and for measuring said first voltage; means responsive to said second laser light pulse for developing a second electrical pulse whose amplitude is a function of the energy of said second laser light pulse; a second signal channel receptive of said second electrical pulse for converting said pulse into a corresponding second direct current voltage and for measuring said second voltage; said first signal channel being provided with means for maintaining said first voltage for a prolonged time after the occurrence of said second laser light pulse and after measurement of said second voltage, whereby said first and second direct current voltages may be compared; field effect transistor gating means in each of said signal channels for receiving said electrical pulses and for conducting them to said voltage converting means; and a flip flop control circuit receptive of said electrical pulses and providing binary outputs coupled to said field effect transistor gating means and operative thereon so as to conduct said first electrical pulse through said first signal channel field effect transistor gating means while blocking the same from said second signal channel and to conduct said second electrical pulse through said second signal channel field effect transistor gating means while blocking the same from said first signal channel.
Claim 2
Dependent Claim
277 words
In a system for measuring the relative intensity of first and second rapidly recurring laser light pulses: means responsive to said first laser light pulse for developing a first electrical pulse whose amplitude is a function of the energy of said first laser light pulse; a first signal channel receptive of said first electrical pulse including means for converting said pulse into a corresponding first direct current voltage and for measuring said first voltage; means responsive to said second laser light pulse for developing a second electrical pulse whose amplitude is a function of the energy of said second laser light pulse; a second signal channel receptive of said second electrical pulse for converting said pulse into a corresponding second direct current voltage and for measuring said second voltage; said first signal channel being provided with means for maintaining said first voltage for a prolonged time after the occurrence of said second laser light pulse and after measurement of said second voltage, whereby said first and second direct current voltages may be compared; field effect transistor gating means in each of said signal channels for receiving said electrical pulses and for conducting them to said voltage converting means; and a flip flop control circuit receptive of said electrical pulses and providing binary outputs coupled to said field effect transistor gating means and operative thereon so as to conduct said first electrical pulse through said first signal channel field effect transistor gating means while blocking the same from said second signal channel and to conduct said second electrical pulse through said second signal channel field effect transistor gating means while blocking the same from said first signal channel.
Claim 3
Dependent Claim
27 words
The invention according to claim 1, and further including means provided within said second channel for prolonging said second voltage for the duration of said first voltage.
Claim 4
Dependent Claim
28 words
The invention according to claim 1, wherein said first and second channels are connected in parallel across an input terminal in series with said electrical pulse developing means.
Claim 5
Dependent Claim
27 words
The invention according to claim 1, wherein said means for developing said first electrical pulse is in common with said means for developing said second electrical pulse.
Claim 6
Dependent Claim
194 words
In a system for measuring the relative intensity of time-spaced light pulses from a doubly pulsed laser: means for converting portions of said light pulses into corresponding first and second electrical pulses; first and second signal channels connected in parallel with an input terminal for receiving said electrical pulses; field effect transistor gating means in each of said signal channels; a flip flop control circuit receptive of said electrical pulses and providing binary outputs coupled to said gating means and operative thereon so as to conduct said first electrical pulse through said first signal channel field effect transistor gating means while blocking the same from said second signal channel and to conduct said second electrical pulse through said second signal channel field effect transistor gating means while blocking the same from said first signal channel; means in said first and second signal channels for converting said electrical pulses from said field effect transistor gating means into corresponding first and second direct current signals; means in said signal channels from holding said direct current signal for contemporaneous measurement; and means for measuring the relative amplitudes of said direct current signals while they are contemporaneously held.
Claim 7
Dependent Claim
194 words
In a system for measuring the relative intensity of time-spaced light pulses from a doubly pulsed laser: means for converting portions of said light pulses into corresponding first and second electrical pulses; first and second signal channels connected in parallel with an input terminal for receiving said electrical pulses; field effect transistor gating means in each of said signal channels; a flip flop control circuit receptive of said electrical pulses and providing binary outputs coupled to said gating means and operative thereon so as to conduct said first electrical pulse through said first signal channel field effect transistor gating means while blocking the same from said second signal channel and to conduct said second electrical pulse through said second signal channel field effect transistor gating means while blocking the same from said first signal channel; means in said first and second signal channels for converting said electrical pulses from said field effect transistor gating means into corresponding first and second direct current signals; means in said signal channels from holding said direct current signal for contemporaneous measurement; and means for measuring the relative amplitudes of said direct current signals while they are contemporaneously held.
Claim 8
Dependent Claim
39 words
The invention according to claim 5, wherein each of said signal channel includes a capacitor charging circuit for developing a direct current voltage signal related to the peak amplitude of each of said first and second electrical signals respectively.
Claim 9
Dependent Claim
51 words
The invention according to claim 5, and further including in each signal channel a diode having its anode connected to the gate of one of said field effect transistors and its cathode connected to one of the outputs of said flip flop for controlling the state of the respective field effect.
Claim 10
Dependent Claim
144 words
The invention according to claim 5, wherein said pulse converting means includes in each signal channel an operational amplifier for amplifying said electrical pulse when it is applied to the plus input thereof, a diode in series therewith for conducting said amplified pulse during its rise when said diode is forward biased and for blocking said amplified pulse during its fall when said diode is reverse biased, and a capacitor and a field effect transistor in parallel with each other and in series with said diode and said operational amplifier; said capacitor charging to a voltage corresponding to the peak value of said amplified pulse and holding said voltage so long as said diode is reverse baised and said field effect transistor is normally gated off; said capacitor discharging its voltage through said field effect transistor when the latter is gated on upon command.
Claim 11
Dependent Claim
52 words
The invention according to claim 8 and further including a non-inverting amplifier connected across said capacitor for deriving an output current indicative of the voltage on said capacitor and in feedback arrangement with said operational amplifier for applying a replica of said electrical pulse to the minus input of said operational amplifier.
References Cited (Backward Citations)
US2837639A
Cited
US3325750A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-24 | 1977-03-26 | 1977-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-24 | 1981-03-26 | 1981-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-24 | 1985-03-26 | 1985-09-25 | $7700.00 | Window Closed / Lapsed |