A surface refractive index acquisition system for characterization of a sample is provided. The system comprises a grating device configured to receive the sample, and first and second grating regions. First and second grating periods are selected to provide optical resonances for light respectively in first and second wavelength bands. A light source is configured to illuminate part of the first and second grating regions simultaneously. An imaging system is configured to image light from the grating device and comprises an optical element focusing light in a transverse direction and being invariant in an orthogonal transverse direction, the optical element being oriented such that the longitudinal direction of the grating device is oriented to coincide with the invariant direction of the optical element, and an imaging spectrometer comprising an entrance slit having a longitudinal direction oriented to coincide with the invariant direction of the optical element.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

Various embodiments provide an optical sensor having an optical source, a grating arrangement optically coupled to the optical source to receive a source optical signal from the optical source, the grating arrangement including a chirped FBG having a defined spectral profile, wherein, in response to a first change in at least one parameter interacting with the chirped FBG, the defined spectral profile is shifted in a first direction relative to a reference spectral profile, and the grating arrangement is configured, in response thereto, to generate a first output optical signal corresponding to the first change, and wherein, in response to a second change in the at least one parameter interacting with the chirped FBG, the defined spectral profile is shifted in a second direction relative to the reference spectral profile, and the grating arrangement is configured, in response thereto, to generate a second output optical signal corresponding to the second change.

A mobile computing device includes an emissive display panel, where the panel is used as a grating, and spectrometer optics positioned behind/below the emissive display panel. A mobile computing device includes an emissive display panel and a spectrometer positioned below the emissive display panel. The emissive display panel includes a first periodic pattern of pixels that include one or more LEDs and a second periodic pattern of circuit elements that control the pixels, where the first and second periodic patterns are configured to diffract light received from outside the device, which passes through the emissive display, and where the diffraction is wavelength-dependent. The spectrometer is configured to detect intensities of different wavelength ranges of the diffracted light.

Various embodiments of the invention provide systems and methods for low-cost, low-power Array Waveguide Grating (AWG)-based miniaturized Raman spectroscopy for use in non-invasive glucose monitoring systems, such as in wearable devices that require no replenishment of chemicals or enzymes. The AWG may be manufactured using VLSI processing technology, which significantly reduces manufacturing cost and replaces holographic grating as the dispersive component of light. In embodiments, the AWG is integrated with a number of PIN photodiode detectors on a substrate to further reduce cost and signal loss. In embodiments, a prism-coupling method eliminates alignment problems associated with traditional approaches that utilize fiber-coupling methods.

An integrated waveguide based spectrometer is described. The spectrometer comprises a sensing region for receiving multi-wavelength radiation for irradiating a sample in the sensing region, a wavelength demultiplexing element arranged for capturing said multi-wavelength radiation after interaction with the sample and for providing a number of wavelength demultiplexed radiation outputs or a number of different groups of wavelength demultiplexed radiation outputs, an integrated modulator for differently modulating the different demultiplexed radiation outputs or different groups of demultiplexed radiation outputs, and a multiplexer element for multiplexing the differently modulated demultiplexed radiation outputs or the differently grouped demultiplexed radiation outputs.

A time-to-frequency converter transforms an initial single-photon pulse into a transformed pulse such that the temporal waveform of the initial pulse is mapped to the spectrum of the transformed pulse. The time-to-frequency converter includes a dispersive optical element followed by a time lens. The spectrum of the transformed pulse is then measured to determine the arrival time of the initial pulse. The spectrum can be measured using a photon-counting spectrometer that spatially disperses the transformed pulse onto an single-photon detector array. Alternatively, an additional dispersive element can be used with the time-to-frequency converter to implement a time magnifier. The arrival time of the resulting time-magnified pulse can then be measured using time-correlated single-photon counting. This arrival time can then be divided by the magnification factor of the time magnifier to obtain the arrival time of the initial pulse.

Provided are a Bragg grating and a spectroscopy device including the same. The Bragg grating is disposed at each of opposite ends of a resonator for reflecting light of a certain wavelength band and includes a core member extending from a waveguide of the resonator in a lengthwise direction of the waveguide; a plurality of first refractive members protruding from the core member and spaced apart from each other along the lengthwise direction; and a second refractive member filling spaces between the first refractive members and having a refractive index different from a refractive index of the first refractive members.

A photo-detection system includes: a photo-detection apparatus including a light-shielding film, an optically-coupled layer, and a photodetector including first and second photo-detection cells; and an arithmetic circuit that generates, based on first signals and second signals, third signals each representing coherence of light having entered a position of each of the first and second photo-detection cells and generates at least one selected from the group consisting of an average value of the third signals, a standard deviation of the third signals, a ratio between the standard deviation and the average value, and a ratio between an average value of a first portion of the third signals based on light having entered the positions of the first photo-detection cells and an average value of a second portion of the third signals based on light having entered the positions of the second photo-detection cells.

An example embodiment relates to a photonic integrated circuit device and a method for its manufacture. An example device includes a planar detector having at least one photodetector. The device may further include a waveguide layer arranged substantially parallel to the planar detector, the waveguide layer including a first integrated waveguide for guiding a first light signal. A cavity may be formed in the waveguide layer in a region spaced away from the edges of the waveguide layer such as to terminate the first integrated waveguide in that region. A first reflective surface may be provided in the cavity to reflect the first light signal guided by the first integrated waveguide toward a first photodetector of the planar detector.