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: Alloys of GeSbSeTe (GSST) can be used to make actively tunable infrared transmission filters that are small, fast, and solid-state. These filters can be used for hyperspectral imaging, 3D LIDAR, portable bio/chem sensing systems, thermal emission control, and tunable filters. GSST is a low-loss phase-change material that can switch from a low-index (n=3), amorphous state to a high-index (n=4.5), hexagonal state with low loss (k<0.3) over a wavelength range of 2-10 microns or more. The GSST thickness can be selected to provide pure phase modulation, pure amplitude modulation, or coupled phase and amplitude modulation. GSST can be switched thermally in an oven, optically with visible light, or electrically via Joule heating at speeds from kilohertz to Gigahertz. It operates with reversible and polarization independent transmission switching over a wide incident angle (e.g., 0-60 degrees).

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: Electro-optic modulators are disclosed. An electro-optic modulator includes an optical ring resonator, an optical waveguide, and a cavity of electro-optic material. The waveguide has a first portion positioned adjacent the resonator to create a first coupling region and a second portion positioned adjacent the resonator to create a second coupling region. The cavity of electro-optic material is embedded within the waveguide between the first portion and the second portion. A method of optical modulation includes the steps of receiving light into an optical waveguide, coupling a portion of the light from the waveguide into an optical ring resonator at a first coupling region between the waveguide and the resonator, transmitting the light remaining in the waveguide into a cavity of electro-optic material embedded within the waveguide, and transmitting the light from the cavity to a second coupling region between the waveguide and the resonator.

Abstract: In certain embodiments, a system for detecting an agent includes a resonator device configured to receive an agent. The resonator device is also configured to transmit light received from a light source, the transmitted light having an altered peak wavelength due to the presence of the received agent. The system further includes a filter device configured to filter the transmitted light having the altered peak wavelength such that the transmitted light having the altered peak wavelength does not reach one or more detectors of a detector array configured to receive transmitted light not filtered by the filter device. The system further includes a processing system operable to determine that the one or more detectors of the detector array are not generating a signal, the absence of the signal being generated by the one or more detectors of the detector array indicating the presence of the agent.

Abstract: A patterned nonreciprocal optical resonator structure is provided that includes a resonator structure that receives an optical signal. A top cladding layer is deposited on a selective portion of the resonator structure. The top cladding layer is patterned so as to expose the core of the resonator structure defined by the selective portion. A magneto-optically active layer includes a magneto-optical medium being deposited on the exposed core of the resonator structure so as to generate optical non-reciprocity.

Abstract: A patterned nonreciprocal optical resonator structure is provided that includes a resonator structure that receives an optical signal. A top cladding layer is deposited on a selective portion of the resonator structure. The top cladding layer is patterned so as to expose the core of the resonator structure defined by the selective portion. A magneto-optically active layer includes a magneto-optical medium being deposited on the exposed core of the resonator structure so as to generate optical non-reciprocity.

Abstract: A multispectral pixel structure is provided that includes a plurality of stacked cavity arrangements for emitting or detecting a plurality of specified wavelengths, wherein each stacked cavity arrangement having a photoactive layer for spectral emission or detection of one of the specified wavelengths. The photoactive layer is positioned within a resonant cavity stack and the resonant cavity stack being positioned between two adjacent mirror stacks. A plurality of coupling-matching layers are positioned between one or more of the stack mirror arrangements for controlling optical phase and coupling strength between emitted or incident light and resonant modes in each of the stacked cavity arrangements.

Abstract: An infrared photodiode structure is provided. The infrared photodiode structure includes a doped semiconductor layer having ions of certain conductivity. An active photodetecting region is positioned on the doped semiconductor layer for detecting an infrared light signal. The active photodetecting region includes one or more amorphous semiconductor materials so as to allow for high signal-to-noise ratio being achieved by invoking carrier hopping and band conduction, under dark and illuminated conditions.