Abstract: An embodiment of a system includes a light source, an optical assembly, and an electronic circuit. The light source (e.g., a laser) is configured to generate a source optical signal. The optical assembly is configured to direct the source optical signal into an end of an optical-fiber assembly that includes an optical fiber having a section wrapped multiple turns around a mandrel and including mandrel zones, and to receive, from the end of the optical-fiber assembly, a return optical signal. The electronic circuit is configured to select at least one mandrel zone in response to a component of the return optical signal from the at least one mandrel zone, and to detect an acoustic signal incident on the mandrel in response to the component of the return optical signal.

Abstract: An embodiment of a system includes a light source, an optical assembly, and an electronic circuit. The light source (e.g., a laser) is configured to generate a source optical signal. The optical assembly is configured to direct the source optical signal into an end of an optical-fiber assembly that includes an optical fiber having a section wrapped multiple turns around a mandrel and including mandrel zones, and to receive, from the end of the optical-fiber assembly, a return optical signal. The electronic circuit is configured to select at least one mandrel zone in response to a component of the return optical signal from the at least one mandrel zone, and to detect an acoustic signal incident on the mandrel in response to the component of the return optical signal.

Abstract: An embodiment of a system includes a light source, an optical assembly, and an electronic circuit. The light source (e.g., a laser) is configured to generate a source optical signal. The optical assembly is configured to direct the source optical signal into an end of an optical-fiber assembly that includes an optical fiber having a section wrapped multiple turns around a mandrel and including mandrel zones, and to receive, from the end of the optical-fiber assembly, a return optical signal. The electronic circuit is configured to select at least one mandrel zone in response to a component of the return optical signal from the at least one mandrel zone, and to detect an acoustic signal incident on the mandrel in response to the component of the return optical signal.

Abstract: Dental imaging systems include an optical scanner that scans one or more interrogation beams across a portion of at least one tooth to produce a dentally modulated light flux associated with light scattering, absorption, or other interaction of the interrogation beam and a tooth interior. The dentally modulated light flux is detected and processed to produce picture information associated with the tooth. Interrogation wavelengths between 800 nm and 1800 nm can be used to provide images suitable for diagnosis and assessment of demineralization or other defects. Interrogation beams at one or more wavelengths can be used. Multiple detectors can be situated to receive dentally modulated light fluxes at different wavelengths or dentally modulated light fluxes with different directions or different locations. Markers at or on a tooth can be used to for depth determination. Index matching to the tooth can improve image quality.

Abstract: Dental imaging systems include an optical scanner that scans one or more interrogation beams across a portion of at least one tooth to produce a dentally modulated light flux associated with light scattering, absorption, or other interaction of the interrogation beam and a tooth interior. The dentally modulated light flux is detected and processed to produce picture information associated with the tooth. Interrogation wavelengths between 800 nm and 1800 nm can be used to provide images suitable for diagnosis and assessment of demineralization or other defects. Interrogation beams at one or more wavelengths can be used. Multiple detectors can be situated to receive dentally modulated light fluxes at different wavelengths or dentally modulated light fluxes with different directions or different locations. Markers at or on a tooth can be used to for depth determination. Index matching to the tooth can improve image quality.

Abstract: Problems of excessive fading in systems for monitoring single-mode optical fiber for disturbances are addressed by launching into the fiber polarized light having at least two different predetermined launch states of polarization whose respective Stokes vectors are linearly-independent of each other; downstream from the first location, receiving the light from the fiber; analyzing the received light using polarization state analyzer having at least two different analyzer states of polarization that are characterized by respective Stokes vectors that are linearly-independent and detecting the analyzed light to provide corresponding detection signals; deriving from the detection signals measures of changes in polarization transformation properties of the fiber between different times that are invariant under a non-reflective unitary transformation on either the launch states or the detection states; and, on the basis of predefined acceptable physical disturbance criteria determining whether or not the measures

Abstract: Dental imaging systems include an optical scanner that scans one or more interrogation beams across a portion of at least one tooth to produce a dentally modulated light flux associated with light scattering, absorption, or other interaction of the interrogation beam and a tooth interior. The dentally modulated light flux is detected and processed to produce picture information associated with the tooth. Interrogation wavelengths between 800 nm and 1800 nm can be used to provide images suitable for diagnosis and assessment of demineralization or other defects. Interrogation beams at one or more wavelengths can be used. Multiple detectors can be situated to receive dentally modulated light fluxes at different wavelengths or dentally modulated light fluxes with different directions or different locations. Markers at or on a tooth can be used to for depth determination. Index matching to the tooth can improve image quality.

Abstract: Dental imaging systems include an optical scanner that scans one or more interrogation beams across a portion of at least one tooth to produce a dentally modulated light flux associated with light scattering, absorption, or other interaction of the interrogation beam and a tooth interior. The dentally modulated light flux is detected and processed to produce picture information associated with the tooth. Interrogation wavelengths between 800 nm and 1800 nm can be used to provide images suitable for diagnosis and assessment of demineralization or other defects. Interrogation beams at one or more wavelengths can be used. Multiple detectors can be situated to receive dentally modulated light fluxes at different wavelengths or dentally modulated light fluxes with different directions or different locations. Markers at or on a tooth can be used to for depth determination. Index matching to the tooth can improve image quality.

Abstract: A fiber-optic sensor device utilizing modal interference in a multimode optical sensor fiber, having output light from the sensor fiber coupled to an axially separated detection lead fiber, and having light from the detection lead fiber coupled to a substantially uniform light detector.

Abstract: Apparatus for depolarizing light received from a source of light comprises a body of material that defines an optical waveguide, the material of the body and the length of the waveguide being such that when polarized light is propagated through the waveguide, light in one of two polarization eigen states is retarded relative to light in the other polarization eigen state by a time such as to destroy phase coherence between the polarization eigen states of the light emitted by the source. The relative amplitudes of the two polarization eigen states of polarized light entering the wave-guide are adjusted.