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US 10,238,298 B2Granted
Method and apparatus for photoacoustic tomography using optical orbital angular momentum (OAM)
AssigneeNEC Corporation
InventorsTing Wang, Yi Weng
Life of this patent
Estimating the term…
Abstract
A method and system for remote sensing. The method includes applying an orbital angular momentum (OAM) mode on a light beam to generate an OAM light beam having an optical OAM spectrum, exposing a target object to the OAM light beam such that the target object absorbs energy of the OAM light beam to generate ultrasonic emissions, the ultrasonic emissions having a reflected OAM spectrum associated with the target object, and generating a high resolution image of the target object based on the reflected OAM spectrum.
Claims20
A method for remote sensing, comprising:
- applying at least one orbital angular momentum (OAM) mode on a light beam to generate an OAM light beam having an optical OAM spectrum, the OAM light beam forming a complete infinite-dimensional basis for solutions of a paraxial wave equation in terms of Laguerre-Gaussian (LG) modes, wherein a normalized LG mode at a beam waist is expressed in cylindrical coordinates as:
- LG
- m
- ,
- p
-
- (
- ρ
- ,
- φ
- )
- =
- (
- 2
-
- p
- !
- π
-
- (
-
- m
-
- +
- p
- )
- !
- )
- 1
- /
- 2
-
- 1
- η
-
- (
- 2
-
- ρ
- η
- )
-
- m
-
-
- L
- p
-
- m
-
-
- (
- 2
-
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- -
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- im
-
-
- φ
- )
- ,
- wherein m represents an on-axis phase singularity of strength, p represents an index, ρ is a radial cylindrical coordinate, φ is an azimuthal angle, η is the beam waist, and Lp|m| is an associated Laguerre polynomial;
- exposing a target object to the OAM light beam such that the target object absorbs energy of the OAM light beam to generate ultrasonic emissions, the ultrasonic emissions having a reflected OAM spectrum associated with the target object;
- and
- generating a high resolution image of the target object based on the reflected OAM spectrum.
80 more elements
A receiver for remote sensing, the receiver comprising:
- at least one transducer configured to:
- receive a generated OAM light beam having an optical OAM spectrum, the OAM light beam forming a complete infinite-dimensional basis for solutions of a paraxial wave equation in terms of Laguerre-Gaussian (LG) modes, wherein a normalized LG mode at a beam waist is expressed in cylindrical coordinates as:
- LG
- m
- ,
- p
-
- (
- ρ
- ,
- φ
- )
- =
- (
- 2
-
- p
- !
- π
-
- (
-
- m
-
- +
- p
- )
- !
- )
- 1
- /
- 2
-
- 1
- η
-
- (
- 2
-
- ρ
- η
- )
-
- m
-
-
- L
- p
-
- m
-
-
- (
- 2
-
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- -
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- im
-
-
- φ
- )
- ,
- wherein m represents an on-axis phase singularity of strength, p represents an index, ρ is a radial cylindrical coordinate, φ is an azimuthal angle, η is the beam waist, and Lp|m| is an associated Laguerre polynomial;
- and
- detect ultrasonic emissions generated by a target object, wherein the ultrasonic emissions include a reflected orbital angular momentum (OAM) spectrum associated with the target object;
- at least one OAM detector configured to detect the reflected OAM spectrum;
- and
- an image processing device having a processor to generate a high resolution image of the target object based on the reflected OAM spectrum.
83 more elements
A system for remote sensing, comprising:
- a drive signal generating circuit to generate an imaging synchronization signal of a light beam;
- a receiver configured to receive a generated OAM light beam having an optical OAM spectrum, the OAM light beam forming a complete infinite-dimensional basis for solutions of a paraxial wave equation in terms of Laguerre-Gaussian (LG) modes, wherein a normalized LG mode at a beam waist is expressed in cylindrical coordinates as:
- LG
- m
- ,
- p
-
- (
- ρ
- ,
- φ
- )
- =
- (
- 2
-
- p
- !
- π
-
- (
-
- m
-
- +
- p
- )
- !
- )
- 1
- /
- 2
-
- 1
- η
-
- (
- 2
-
- ρ
- η
- )
-
- m
-
-
- L
- p
-
- m
-
-
- (
- 2
-
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- -
- ρ
- 2
- η
- 2
- )
-
- exp
-
- (
- im
-
-
- φ
- )
- ,
- wherein m represents an on-axis phase singularity of strength, p represents an index, ρ is a radial cylindrical coordinate, φ is an azimuthal angle, η is the beam waist, and Lp|m| is an associated Laguerre polynomial;
- at least one orbital angular momentum (OAM) detector to detect a reflected OAM spectrum, wherein the reflected OAM spectrum is provided by ultrasonic emissions generated from a target object absorbing energy of an OAM light beam;
- and
- an imaging processing device having a processor configured to compare a frequency of the synchronization signal with a frequency of the reflected OAM spectrum to generate a high resolution image of a target object.
81 more elements
Dependencies are inferred from the claim text.