Confocal-reflection streak lidar apparatus with strip-shaped photocathode, for applications at a wide range of scales
First Claim
1. A system for imaging a volume of a turbid medium that is living tissue, with objects therein, said system being for use with means for physically shifting at least part of a probe beam and at least part of a reflected beam, together, with respect to said turbid volume, and said system comprising:
- means for projecting a pulsed thin-fan-shaped beam to selectively illuminate, along an Illumination-propagation direction, a thin section of such turbid volume;
means for receiving reflected light back, approximately along the illumination-propagation direction, from the thin section of turbid volume; and
comprising;
first electronic means for time-resolving said received light to derive therefrom successive electronic representations of the light successively received from the illuminated turbid-volume thin section, and second electronic means for distributing the successive electronic-image representations, along an electronic time axis, said distributing of the electronic-image representations being in accordance with elapsed time after operation of the beam-projecting means so that each electronic-image representation is displaced along the electronic time axis substantially in proportion to total propagation distance and time into and out from the turbid-medium thin section, to form a composite electronic representation of the turbid-volume thin section as a function of propagation depth;
means for imposing a substantially common spatial definition and directional restriction, in one dimension, upon (1) the pulsed thin-fan-shaped beam projected by the projecting means and (2) the reflected light received back from the thin section of turbid volume; and
means for sequentially operating the beam-projecting means, during operation of such physically-shifting means, to project a sequence of beam pulses to illuminate successive thin sections, and generate a corresponding sequence of composite electronic representations; and
wherein;
the projecting means comprise a pulsed laser that emits a short laser pulse of duration in a picosecond range.
1 Assignment
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Accused Products
Abstract
The system images the volume of a turbid medium and detects the contents. The medium can be water or air, or living tissue, or almost any other material which is at least partially light-transmissive. The system includes a light source for producing a series of discrete fan-shaped pulse beams that are substantially uniform in intensity or have been peaked at the edges of the fan to illuminate sections of the medium, a streak tube with a large, thin-slit-shaped photocathode for collecting the maximum amount of light from weak returns, a field-limiting slit disposed in front of the cathode for removing multiply scattered light, a large-aperture optical element for collecting and focusing the reflected portions of the pulse beam on the field-limiting slit and the cathode, and an array of detectors. A volume display of the medium is generated by translating the transmitter and receiver normal to the longitudinal axis of the pulse beam, to illuminate adjacent sections of the medium, and combining the sections to provide a volume display. All, or substantially all, of the light returned from each pulse beam is used. Vehicle motion can be used to provide the scan of the beam. Applications range from foggy sky surveillance at multiple-kilometer scale to location of fractional-millimeter tumors in a human breast.
46 Citations
32 Claims
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1. A system for imaging a volume of a turbid medium that is living tissue, with objects therein, said system being for use with means for physically shifting at least part of a probe beam and at least part of a reflected beam, together, with respect to said turbid volume, and said system comprising:
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means for projecting a pulsed thin-fan-shaped beam to selectively illuminate, along an Illumination-propagation direction, a thin section of such turbid volume;
means for receiving reflected light back, approximately along the illumination-propagation direction, from the thin section of turbid volume; and
comprising;
first electronic means for time-resolving said received light to derive therefrom successive electronic representations of the light successively received from the illuminated turbid-volume thin section, and second electronic means for distributing the successive electronic-image representations, along an electronic time axis, said distributing of the electronic-image representations being in accordance with elapsed time after operation of the beam-projecting means so that each electronic-image representation is displaced along the electronic time axis substantially in proportion to total propagation distance and time into and out from the turbid-medium thin section, to form a composite electronic representation of the turbid-volume thin section as a function of propagation depth;
means for imposing a substantially common spatial definition and directional restriction, in one dimension, upon (1) the pulsed thin-fan-shaped beam projected by the projecting means and (2) the reflected light received back from the thin section of turbid volume; and
means for sequentially operating the beam-projecting means, during operation of such physically-shifting means, to project a sequence of beam pulses to illuminate successive thin sections, and generate a corresponding sequence of composite electronic representations; and
wherein;
the projecting means comprise a pulsed laser that emits a short laser pulse of duration in a picosecond range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A system for imaging a volume of a turbid medium that is biological tissue, with objects therein, said system being for use with means for physically shifting at least part of a probe beam and at least part of a reflected beam, together, with respect to said turbid volume, and said system comprising:
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means for projecting a pulsed thin-fan-shaped beam to selectively illuminate, along an illumination-propagation direction, a thin section of such turbid volume;
means for receiving reflected light back, approximately along the illumination-propagation direction, from the thin section of turbid volume; and
comprising;
first electronic means for time-resolving said received light to derive therefrom successive electronic representations of the light successively received from the illuminated turbid-volume thin section, and second electronic means for distributing the successive electronic-image representations, along an electronic time axis, said distributing of the electronic-image representations being in accordance with elapsed time after operation of the beam-projecting means so that each electronic-image representation is displaced along the electronic time axis substantially in proportion to total propagation distance and time into and out from the turbid-medium thin section, to form a composite electronic representation of the turbid-volume thin section as a function of propagation depth;
means for imposing a substantially common spatial definition and directional restriction, in one dimension, upon (1) the pulsed thin-fan-shaped beam projected by the projecting means and (2) the reflected light received back from the thin section of turbid volume; and
means for sequentially operating the beam-projecting means, during operation of such physically-shifting means, to project a sequence of beam pulses to illuminate successive thin sections, and generate a corresponding sequence of composite electronic representations; and
wherein;
the projecting means comprise a pulsed laser that emits a short laser pulse of duration in a picosecond range. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
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Specification