Abstract: An apparatus includes a surface acoustic wave (SAW) sensor. The SAW sensor includes a piezoelectric substrate. The SAW sensor also includes first and second interdigitating transistors over the piezoelectric substrate. The first interdigitating transistor is configured to convert an input electrical signal into an acoustic wave. The second interdigitating transistor is configured to convert the acoustic wave into an output electrical signal. The piezoelectric substrate is configured to transport the acoustic wave. The SAW sensor further includes a detection layer over the piezoelectric substrate and positioned at least partially between the first and second interdigitating transistors. The detection layer includes (i) antibodies configured to bind to one or more biological analytes and (ii) a hydrogel layer over the antibodies.

Abstract: A Positron Emission Tomography (PET) device, detector for a PET device and method of performing PET. The detector includes a scintillator and a photodetector. The scintillator includes a crystal defining a receiving axis and having a receiving face for receiving a gamma ray. A dopant concentration of the crystal varies along the receiving axis with a distance from the receiving face. The photodetector is configured to generate an impulse response in response to an interaction between the gamma ray and the crystal. A decay profile of the impulse response is related to a local dopant concentration of the crystal at the location of the interaction and the distance of the interaction from the receiving face.

Abstract: An apparatus includes a surface acoustic wave (SAW) sensor. The SAW sensor includes a piezoelectric substrate. The SAW sensor also includes first and second interdigitating transistors over the piezoelectric substrate. The first interdigitating transistor is configured to convert an input electrical signal into an acoustic wave. The second interdigitating transistor is configured to convert the acoustic wave into an output electrical signal. The piezoelectric substrate is configured to transport the acoustic wave. The SAW sensor further includes a detection layer over the piezoelectric substrate and positioned at least partially between the first and second interdigitating transistors. The detection layer includes (i) antibodies configured to bind to one or more biological analytes and (ii) a hydrogel layer over the antibodies.

Abstract: A Positron Emission Tomography (PET) device, detector for a PET device and method of performing PET. The detector includes a scintillator and a photodetector. The scintillator includes a crystal defining a receiving axis and having a receiving face for receiving a gamma ray. A dopant concentration of the crystal varies along the receiving axis with a distance from the receiving face. The photodetector is configured to generate an impulse response in response to an interaction between the gamma ray and the crystal. A decay profile of the impulse response is related to a local dopant concentration of the crystal at the location of the interaction and the distance of the interaction from the receiving face.

Abstract: A rolling slip ring structure is disclosed incorporating coupled optical waveguides that provide an optical signal pathway through at least three coplanar optical waveguide rings. The inner, outer and center rings of the rolling slip ring structure are configured such that any or all of the rings can rotate about a central axis perpendicular to the plane of the rings and at the center of the inner and outer optical waveguide rings. The center optical waveguide ring can also rotate about an axis that is perpendicular to the plane containing the three optical waveguide rings and is at the center of the center ring. The optical coupling length between the optical waveguide rings in the system remains constant regardless of rotation of any or all of the optical waveguide rings.

Abstract: An instrument for photodynamic therapy applies treatment light from a dye laser, white light, and ultraviolet fluorescence excitation light from an LED onto a lesion and surrounding areas in a time-multiplexed manner. The reflected white light is analyzed in a spectrometer to determine a correction for the dynamic optical spectral properties of the patient's tissue. Light emitted by fluorescence from the lesion and the surrounding areas is analyzed in another spectrometer, and the results are corrected in a computer, using the correction. An optical switch has been developed for the instrument, using a bistable solenoid and a sled.

Abstract: In one embodiment, a rolling slip ring structure is disclosed incorporating coupled optical waveguides that provide an optical signal pathway through at least three coplanar optical waveguide rings. The inner, outer and center rings of the rolling slip ring structure are configured such that any or all of the rings can rotate about a central axis perpendicular to the plane of the rings and at the center of the inner and outer optical waveguide rings. The center optical waveguide ring can also rotate about an axis that is perpendicular to the plane containing the three optical waveguide rings and is at the center of the center ring. The optical coupling length between the optical waveguide rings in the system remains constant regardless of rotation of any or all of the optical waveguide rings. In some embodiments, absorbing optical materials and/or mechanical scattering mechanisms are utilized to counteract the effects of possible whispering gallery mode resonances.

Abstract: Methods and apparatus for a free space coupler to receive light from a laser via air. In one embodiment, a system comprises a laser source, a mirror optically aligned to the laser source, a first mount to control a position of the mirror, a free-space coupler to receive light from the mirror, a beam splitter to receive light exiting the coupler, a first detector to receive light reflected from the beam splitter, a second mount coupled to the first detector and to the coupler to control a position of the coupler from information from the first detector, and a second detector to receive light reflected by the coupler and the mirror, wherein the second detector is coupled to the first mount for positioning the mirror with respect to the coupler.

Abstract: Methods and apparatus for a fiber optic display system. In one embodiment, a fiber optic display screen comprises a laser source, relay optics to receive an output from the laser source, condenser optics coupled to the relay optics, a digital pixelator coupled to the condenser optics, a fiber optic transmission line coupled to the digital pixelator, and a fiber optic screen provided by terminal ends of fibers in the fiber optic transmission line.

Abstract: Methods and apparatus for a fiber optic display screen of adjustable size. In one embodiment, a screen comprises: a plurality of pixels formed by a terminal end of at least one optical fiber, wherein the pixels are substantially equidistant from each other along a first axis in a first screen size and in a second screen size that is larger than the first size.

Abstract: Methods and apparatus for a fiber optic display screen that comprises pixels forming the screen, wherein each of the pixels comprise terminal ends of multiple optical fibers, wherein a first pixel comprises: a first optical fiber terminal end having a first cleaving to generate an image for a first viewing angle, and a second optical fiber terminal end having a second cleaving different than the cleaving of the first optical fiber terminal end to generate an image for a second viewing angle for providing different content at the first and second viewing angles.

Abstract: Methods and apparatus for a fiber optic display system. In one embodiment, a fiber optic display screen comprises a laser source, relay optics to receive an output from the laser source, condenser optics coupled to the relay optics, a digital pixelator coupled to the condenser optics, a fiber optic transmission line coupled to the digital pixelator, and a fiber optic screen provided by terminal ends of fibers in the fiber optic transmission line.

Abstract: Methods and apparatus for a free space coupler to receive light from a laser via air. In one embodiment, a system comprises a laser source, a mirror optically aligned to the laser source, a first mount to control a position of the mirror, a free-space coupler to receive light from the mirror, a beam splitter to receive light exiting the coupler, a first detector to receive light reflected from the beam splitter, a second mount coupled to the first detector and to the coupler to control a position of the coupler from information from the first detector, and a second detector to receive light reflected by the coupler and the mirror, wherein the second detector is coupled to the first mount for positioning the mirror with respect to the coupler.

Abstract: Methods and apparatus for a fiber optic display screen of adjustable size. In one embodiment, a screen comprises: a plurality of pixels formed by a terminal end of at least one optical fiber, wherein the pixels are substantially equidistant from each other along a first axis in a first screen size and in a second screen size that is larger than the first size.

Abstract: A method for delivering photodynamic therapy (PDT) while performing dose metric monitoring and treatment feedback-driven control is presented. Photodynamic therapy is initiated with irradiation of light at a first irradiance. A set of fluorescence and reflectance spectroscopic measurements are taken at prescribed intervals during the therapy of the treatment region. Spectra are analyzed to determine dose metrics of the therapy such as fluorescence photobleaching of the sensitizer and blood oxygen status and optical properties of the treatment region. This information is then used to determine an optimal fluence rate given those parameters and the region is irradiated with a second irradiance. This process is continued until either the entire prescribed fluence is delivered to the region or a predetermined extent of photosensitizer bleaching is achieved.

Abstract: In a first embodiment, there is no monitoring, and instead light is delivered according to a predetermined ‘recipe.’ In a second embodiment, the instrumentation provides a means for making the reflectance measurements during therapy without requiring the brief interruption. This device may therefore allow more accurate measurement of treatment-induced changes to the reflectance measurement. In a third embodiment, an adjustable aperture is used to constrict the area of a treatment beam.

Abstract: An optical probe has multiple side-firing optical fibers which terminate in a linearly staggered fashion. A central fiber can be used as well. In diagnostic techniques, one fiber can be used as an emitter, while the others are used as receivers, or various fibers can be used as emitters and receivers at different times to form a map of the area. In therapeutic techniques, the treatment light can be emitted from the fibers in parallel or in sequence, and the fluence can be independently adjusted for each of the fibers.

Abstract: An instrument for photodynamic therapy applies treatment light from a dye laser, white light, and ultraviolet fluorescence excitation light from an LED onto a lesion and surrounding areas in a time-multiplexed manner. The reflected white light is analyzed in a spectrometer to determine a correction for the dynamic optical spectral properties of the patient's tissue. Light emitted by fluorescence from the lesion and the surrounding areas is analyzed in another spectrometer, and the results are corrected in a computer, using the correction. An optical switch has been developed for the instrument, using a bistable solenoid and a sled.

Abstract: A common-path, point-diffraction, phase-shifting interferometer uses a half wave plate having a diffractive element, such as pin hole. A coherent, polarized light source simultaneously generates a reference beam from the diffractive element and an object beam from remaining portions of the light going through the half wave plate. The reference beam has a nearly spherical wavefront. Each of the two beams possesses a different polarization state. The object and reference beams are then independently phase modulated by a polarization sensitive phase modulator that shifts phase an amount depending on applied voltage and depending on polarization state of the incident light. A polarizer is then used to provide the object and reference beams in the same polarization state with equal intensities so they can interfere to create an interferogram with near unity contrast.

Abstract: A common-path, point-diffraction, phase-shifting interferometer uses a half wave plate having a diffractive element, such as pin hole. A coherent, polarized light source simultaneously generates a reference beam from the diffractive element and an object beam from remaining portions of the light going through the half wave plate. The reference beam has a nearly spherical wavefront. Each of the two beams possesses a different polarization state. The object and reference beams are then independently phase modulated by a polarization sensitive phase modulator that shifts phase an amount depending on applied voltage and depending on polarization state of the incident light. A polarizer is then used to provide the object and reference beams in the same polarization state with equal intensities so they can interfere to create an interferogram with near unity contrast.