Abstract: A sensor, such as a photoplethysmography sensor, for non-invasively monitoring a characteristic of an organism, such as a vital body sign. The sensor has multiple light sources disposed on a substrate and an array of optical probing channels for conveying light from the light sources to a probed region. Each detector pixel of an array of detector pixels receives light from a respective optical detection channel after interaction with a subregion of the probed region and spatial filtering, and generates a corresponding pixel signal.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: An apparatus for generating a spectral image includes a filter to receive incident light. The filter has a variable refractive index. The apparatus also includes a modulator, operably coupled to the filter, to modulate the variable refractive index of the filter so as to generate a plurality of optical patterns from the incident light. The plurality of optical patterns represents the spectral image and each optical pattern in the plurality of optical patterns corresponds to a different modulation of the variable refractive index. The apparatus further includes a detector, in optical communication with the filter, to detect the plurality of optical patterns.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: An apparatus for generating a spectral image includes a filter to receive incident light. The filter has a variable refractive index. The apparatus also includes a modulator, operably coupled to the filter, to modulate the variable refractive index of the filter so as to generate a plurality of optical patterns from the incident light. The plurality of optical patterns represents the spectral image and each optical pattern in the plurality of optical patterns corresponds to a different modulation of the variable refractive index. The apparatus further includes a detector, in optical communication with the filter, to detect the plurality of optical patterns.

Abstract: State-of-the-art portable Raman spectrometers use discrete free-space optical components that must be aligned well and that don't tolerate vibrations well. Conversely, the inventive spectrometers are made with monolithic photonic integration to fabricate some or all optical components on one or more planar substrates. Photonic integration enables dense integration of components, eliminates manual alignment and individual component assembly, and yields superior mechanical stability and resistance to shock or vibration. These features make inventive spectrometers especially suitable for use in high-performance portable or wearable sensors. They also yield significant performance advantages, including a large (e.g., 10,000-fold) increase in Raman scattering efficiency resulting from on-chip interaction of the tightly localized optical mode and the analyte and a large enhancement in spectral resolution and sensitivity resulting from the integration of an on-chip Fourier-transform spectrometer.

Abstract: An alloy of GexSbySezTem includes atoms of Ge, Sb, Se, and Te that form a crystalline structure having a plurality of vacancies randomly distributed in the crystalline structure. The alloy can be used to construct an optical device including a first waveguide to guide a light beam and a modulation layer disposed on the first waveguide. The modulation includes the alloy of GexSbySezTem which has a first refractive index n1 in an amorphous state and a second refractive index n2, greater than the first refractive index by at least 1, in a crystalline state. The first waveguide and the modulation layer are configured to guide about 1% to about 50% of the light beam in the modulation layer when the alloy is in the amorphous state and guide no optical mode when the alloy is in the crystalline state.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: An optical interconnect system has first and second waveguides each with wedge-shaped cross-section at a first end, disposed over an optical modulator. The optical modulator is a surface-plasmon multi quantum well (SP-MQW) modulator, the first waveguide an input waveguide and the second waveguide configured an output waveguide. In embodiments the SP-MQW modulator has multiple semiconductor layers disposed atop a lower metal layer between 10 and 300 nanometers thick and configured such that incident light is reflected at the lower metal layer unless a voltage is applied to the semiconductor layers, when incident light is coupled into a surface plasmon mode in the lower metal layer.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: A multi-channel optical imaging and stimulation system includes a light source to deliver light beams into a light guide. Different light beams are coupled into different spatial modes supported by the light guide. The light guide includes multiple segments, each of which defines a window to couple a specified group of spatial modes out of the light guide to illuminate or stimulate a target. Light reflected, scattered, or emitted by the target is also collected by the windows in the light guide. The light collected by different windows is detected by different pixels of a detector, thereby creating a correspondence between the pixel location and the spatial location of site at which the light is collected. An image of the target is then reconstructed based on this correspondence.

Abstract: A photovoltaic (PV) apparatus includes a substrate having a first substrate surface and a second substrate surface. A cavity fabricated in the substrate extends from the first substrate surface toward the second substrate surface. The cavity defines a first end to receive incident light, a second end opposite the first end, and a side surface, which extends from the first end to the second end to concentrate the incident light, received by the first end, toward the second end. The PV apparatus also includes a photovoltaic (PV) cell, in optical communication with the second end of the at least one cavity, to convert the incident light into electricity.

Abstract: An apparatus for generating a spectral image includes a filter to receive incident light. The filter has a variable refractive index. The apparatus also includes a modulator, operably coupled to the filter, to modulate the variable refractive index of the filter so as to generate a plurality of optical patterns from the incident light. The plurality of optical patterns represents the spectral image and each optical pattern in the plurality of optical patterns corresponds to a different modulation of the variable refractive index. The apparatus further includes a detector, in optical communication with the filter, to detect the plurality of optical patterns.

Abstract: A spectrometer includes an interferometer having a first interference arm and a second interference arm to produce interference patterns from incident light. At least one of the interference arms includes a series of cascaded optical switches connected by two (or more) waveguides of different lengths. Each optical switch directs the incident light into one waveguide or another, thereby changing the optical path length difference between the first interference arm and the second interference arm. This approach can be extended to multi-mode incident light by placing parallel interferometers together, each of which performs spectroscopy of one single mode in the multi-mode incident light. To maintain the compactness of the spectrometer, adjacent interferometers can share one interference arm.

Abstract: Optical interconnect systems and methods are disclosed. An optical interconnect system includes a substrate, an optical waveguide, and first and second modulators. The optical waveguide has a first waveguide portion extending to a first coupling structure, a second waveguide portion extending from the first coupling structure to a second coupling structure, and a third waveguide portion extending from the second coupling structure. The first modulator is positioned adjacent the first coupling structure, and the second modulator is positioned adjacent the second coupling structure. The optical interconnect method includes modulating light with a first modulator to produce one-time modulated light, and modulating the one-time modulated light with a second modulator to produce two-time modulated light.

Abstract: Dispersive optical systems and methods are disclosed, as well as energy generation systems utilizing such systems in combination with photovoltaic cells. A dispersive optical system includes an optical element, a layer of high-dispersion microprisms, and a layer of low-dispersion microprisms. The optical element is configured to focus a light beam. The layer of high-dispersion microprisms is configured to refract the light beam. The layer of low-dispersion microprisms is configured to refract the light beam. The dispersive optical system is configured to optically concentrate and disperse input light incident thereupon into an output comprising a plurality of bands of light each having a different wavelength. A method of optical dispersion includes focusing a light beam with an optical element, refracting the light beam with a layer of high-dispersion microprisms, and refracting the light beam with a layer of low-dispersion microprisms.

Abstract: Optical interconnect systems and methods are disclosed. An optical interconnect system includes a substrate, a first waveguide, and a free-space coupling structure. The first waveguide is disposed on the substrate. The free-space coupling structure is adjacent the first waveguide. The free-space coupling structure redirects light propagating through the first waveguide in a first direction out of the first waveguide in a second direction different from the first direction. An optical interconnect method comprises transmitting light through a first waveguide in a first direction; and redirecting the light out of the first waveguide in a second direction different from the first direction with a free-space coupling structure disposed in the first waveguide.

Abstract: Systems and methods for modulator-based optical interconnections are disclosed. An optical interconnect system comprises a substrate, a wave path, a coupling structure, and a modulator. The wave path may be a waveguide disposed on the substrate. The coupling structure is coupled to the substrate and disposed within the wave path. The modulator is positioned between the substrate and the coupling structure. An optical interconnect method comprises the steps of transmitting light through a wave path, redirecting the light onto a modulator with a coupling structure, modulating the light from the coupling structure with the modulator; and redirecting modulated light from the modulator into the wave path with the coupling structure.

Abstract: Optical sheets, light collection and conversion systems and methods of forming optical sheets are provided. An optical sheet includes a light guide layer having at least one light guide and a light concentrator layer adjacent to the light guide layer for concentrating incident light. Each light guide has a substantially uniform thickness with respect to a propagation direction of light through the light guide and includes a plurality of input-coupling elements and at least one output-coupling element. The light concentrator layer includes a plurality of concentrator elements optically coupled to the plurality of input-coupling elements of the respective light guide. Each light guide is configured to combine the concentrated light from the respective plurality of concentrator elements and to guide the combined light to the at least one output-coupling element.

Abstract: Optical interconnect systems and methods are disclosed. An optical interconnect system includes a substrate, an optical waveguide, and first and second modulators. The optical waveguide has a first waveguide portion extending to a first coupling structure, a second waveguide portion extending from the first coupling structure to a second coupling structure, and a third waveguide portion extending from the second coupling structure. The first modulator is positioned adjacent the first coupling structure, and the second modulator is positioned adjacent the second coupling structure. The optical interconnect method includes modulating light with a first modulator to produce one-time modulated light, and modulating the one-time modulated light with a second modulator to produce two-time modulated light.