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US4931704A Expired / Lapsed US ⏱️ 0.0 years remaining

Ultrafast sampling oscilloscope

Assignee: Research Foundation of City University of New York
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Filing: 1988-12-09
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Granted: 1990-06-05
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Expires: 2008-12-09
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Abstract

Abstract A femtosecond sampling oscilloscope includes a femtosecond laser for generating a pulse of light in the femtosecond range and a beam splitter for splitting the pulse of light into pulses traveling along first and second beam paths. A photoconductive switch disposed along the first beam path is used to produce an electrical stimulus output at a first output port, an electrical pulse output at a second output port and an optical output at a third output port. A photomultiplier tube having a strip line photocathode receives the pulse of light traveling along the first beam path. An input port is coupled to the photocathode. In use, the output signal at one of the output ports is connected to a test device producing a test voltage signal which is applied to the input port. When the test voltage signal and the light pulse traveling along the second path intersect on the photocathode in space and time, an electrical signal output is produced at the photomultiplier tube. The output is processed and/or stored in a computer and then, when desired, displayed on a cathode ray tube.

Inventors

  • 👤 Robert R. Alfano
  • 👤 Ardie D. Walser

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 20:11
CPC Classifications
H; H01; H01J; H01J43/00; H01J43/04; H01J43/30; G; G01; G01R; G01R13/00; G01R13/20; G01R13/22; G01R13/34; H01J43/06; H01J43/08

Claims Analysis

Total Claims: 22
Claim 1
Independent Claim 205 words
A sampling oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) means for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a picosecond voltage pulse to be time resolved, the input port being coupled to the photocathode, and (g) means coupled to the anode of the photomultiplier tube for displaying the voltage signal at the anode of the photomultiplier tube, (h) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing a voltage signal at the anode of the photomultiplier tube when the picosecond voltage pulse and the light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 2
Dependent Claim 205 words
A sampling oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) means for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a picosecond voltage pulse to be time resolved, the input port being coupled to the photocathode, and (g) means coupled to the anode of the photomultiplier tube for displaying the voltage signal at the anode of the photomultiplier tube, (h) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing a voltage signal at the anode of the photomultiplier tube when the picosecond voltage pulse and the light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 3
Dependent Claim 33 words
The oscilloscope as recited in claim 1 and further comprising computer means coupled between said photomultiplier tube and said display means for processing and/or storing the output signal received from the photomultiplier tube.
Claim 4
Dependent Claim 22 words
The oscilloscope as recited in claim 2 and wherein said means for generating a femtosecond pulse of light comprises a femtosecond laser.
Claim 5
Dependent Claim 24 words
The oscilloscope as recited in claim 3 and wherein said means for displaying the output from the computer means includes a cathode ray tube.
Claim 6
Dependent Claim 16 words
The oscilloscope as recited in claim 4 and wherein said photocathode has a transmission line configuration.
Claim 7
Dependent Claim 256 words
A sampling oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) a femtosecond laser for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accelerating mesh and an anode, the photocathode having a transmission line configuration and being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) delay line means for delaying the time of arrival of the pulse traveling along the second beam path at the photomultiplier tube, (g) an input port for receiving a picosecond voltage signal, the input port being coupled to the photocathode, and (h) computer means coupled to the anode of the photomultiplier tube for processing and/or storing the signal received at the anode of the photomultiplier tube, and (i) means including a cathode ray tube for displaying the picosecond signal processed and/or stored by the computer means, (j) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of the photomultiplier tube when the picosecond voltage signal and the femtosecond light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 8
Dependent Claim 256 words
A sampling oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) a femtosecond laser for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accelerating mesh and an anode, the photocathode having a transmission line configuration and being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) delay line means for delaying the time of arrival of the pulse traveling along the second beam path at the photomultiplier tube, (g) an input port for receiving a picosecond voltage signal, the input port being coupled to the photocathode, and (h) computer means coupled to the anode of the photomultiplier tube for processing and/or storing the signal received at the anode of the photomultiplier tube, and (i) means including a cathode ray tube for displaying the picosecond signal processed and/or stored by the computer means, (j) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of the photomultiplier tube when the picosecond voltage signal and the femtosecond light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 9
Dependent Claim 30 words
The oscilloscope of claim 6 and further including second and third output ports for providing output pulse signals related to the pulse of light traveling along the first beam path.
Claim 10
Dependent Claim 20 words
The oscilloscope of claim 7 and wherein the output signal from the first output port is an electrical pulse signal.
Claim 11
Dependent Claim 20 words
The oscilloscope of claim 8 and wherein the output signal from the third output port is an optical pulse signal.
Claim 12
Dependent Claim 26 words
The oscilloscope of claim 9 and further including delay line means for delaying the time of arrival of the pulse traveling along the first beam path.
Claim 13
Dependent Claim 13 words
The oscilloscope of claim 6 and wherein the delay line means is movable.
Claim 14
Dependent Claim 21 words
The oscilloscope of claim 11 and further including attenuator means at the first output port for attenuating the first output signal.
Claim 15
Dependent Claim 15 words
The oscilloscope of claim 12 and further including means for moving the delay line means.
Claim 16
Dependent Claim 251 words
An oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) means for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a picosecond voltage pulse the input port being coupled to the photocathode, and (g) a photoconductive switch at the first output port for receiving the light pulse traveling along the first beam path and outputting an electrical pulse, (h) delay line means for delaying the time of arrival of the pulse traveling along the first beam path, (i) means for moving the delay line means (j) means coupled to the output of the photomultiplier tube for displaying the output at the anode of the photomultiplier tube, (k) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of the photomultiplier tube when the picosecond voltage pulse and the light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 17
Dependent Claim 251 words
An oscilloscope for time resolving picosecond voltage pulses with femtosecond resolution comprising: (a) means for generating a femtosecond pulse of light, (b) means for splitting said femtosecond pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a picosecond voltage pulse the input port being coupled to the photocathode, and (g) a photoconductive switch at the first output port for receiving the light pulse traveling along the first beam path and outputting an electrical pulse, (h) delay line means for delaying the time of arrival of the pulse traveling along the first beam path, (i) means for moving the delay line means (j) means coupled to the output of the photomultiplier tube for displaying the output at the anode of the photomultiplier tube, (k) whereby, a picosecond voltage pulse may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of the photomultiplier tube when the picosecond voltage pulse and the light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 18
Dependent Claim 12 words
The oscilloscope of claim 14 and wherein the photocathode is a microstrip.
Claim 19
Dependent Claim 18 words
The oscilloscope of claim 14 and wherein the means for moving the delay means comprises a stepping motor.
Claim 20
Dependent Claim 18 words
The oscilloscope of claim 16 and wherein the means for moving the delay means comprises an oscillating motor.
Claim 21
Dependent Claim 185 words
A sampling oscilloscope comprising: (a) means for generating a pulse of light, (b) means for splitting said pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a voltage signal, the input port being coupled to the photocathode, and (g) means coupled to the output of the photomultiplier tube for displaying the signal at the anode of the photomultiplier tube, (h) whereby, a voltage signal may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of photomultiplier tube when the voltage signal and the light pulse traveling along the second path overlap in time and space on the photocathode.
Claim 22
Dependent Claim 185 words
A sampling oscilloscope comprising: (a) means for generating a pulse of light, (b) means for splitting said pulse of light into a plurality of pulses each traveling along a different beam path, (c) a first output port providing an output pulse signal related to the pulse of light traveling along a first one of the beam paths, (d) a photomultiplier tube having a photocathode, an accellerating mesh and an anode, the photocathode being positioned along a second one of the beam paths, (e) means negatively biasing the accellerating mesh relative to the anode, (f) an input port for receiving a voltage signal, the input port being coupled to the photocathode, and (g) means coupled to the output of the photomultiplier tube for displaying the signal at the anode of the photomultiplier tube, (h) whereby, a voltage signal may be applied to the input port to negatively bias the photocathode relative to the accellerating mesh producing an output signal at the anode of photomultiplier tube when the voltage signal and the light pulse traveling along the second path overlap in time and space on the photocathode.

References Cited (Backward Citations)

US4434399A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-04 1993-12-04 1994-06-05 $2000.00 Window Closed / Lapsed
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