A waveguide spectrometer includes at least one substrate layer with at least one surface waveguide extending from an inlet face to guide the received light; at least one evanescent field sampler in the waveguide to out-couple light along the waveguide; at least one light sensing unit to detect the out-coupled light, each electrically connected to an electronic read out system; and means to achieve counter propagating optical signals inside the waveguide to obtain interference between the counter propagating optical signals generating an interference pattern along the waveguide. A compact and simple construction with improved spectral range/bandwidth of the spectrometer can be achieved with at least one modulator integrated into the sampling waveguide structure to enable conditioning of the guided optical signals and for changing the refractive index. The integrated modulator is realized by electrodes placed aside directly neighboured to the guiding core resp. waveguide generating an optical phases shift required for scanning the interferogram.

A hyperspectral imaging system has a processor to receive hyperspectral imaging parameters and produce a series of images to be acquired at a series of retardances at a series of retardance times, a hyperspectral imaging component having an input polarizer to polarize an incoming beam of light, a liquid crystal variable retarder to receive the polarized beam of light and to produce wavelength-dependent polarized light, an output polarizer to receive the wavelength-dependent polarized light and to convert polarization state information into a form detectable as light intensity, a voltage source connected to the liquid crystal variable retarder, and a retardance controller. The retardance controller receives the series of retardances at a series of retardance times and produces a series of voltages at a series of voltage times to apply to the liquid crystal variable retarder. A focal plane array, synchronized with the retardance controller, receives the light in a form detectable as light intensity and converts the light to a series of images.

We disclose an on-chip photonic spectroscopy system capable of dramatically improving the signal-to-noise ratio (SNR), dynamic range, and reconstruction quality of Fourier transform spectrometers. Secondly, we disclose a system of components that makes up a complete on-chip RF spectrum analyzer with low-cost and high-performance.

A spatial Fourier transform spectrometer is disclosed. The Fourier transform spectrometer includes a Fabry-Perot interferometer with first and second optical surfaces. The gap between the first and second optical surfaces spatially varies in a direction that is orthogonal to the optical axis of the Fourier transform spectrometer. The Fabry-Perot interferometer creates an interference pattern from input light. An image of the interference pattern is captured by a detector, which is communicatively coupled to a processor. The processor is configured to process the interference pattern image to determine information about the spectral content of the input light.

A non-paraxial Talbot spectrometer includes a transmission grating to receive incident light. The grating period of the transmission grating is comparable to the wavelength of interest so as to allow the Talbot spectrometer to operate outside the paraxial limit. Light transmitted through the transmission grating forms periodic Talbot images. A tilted detector is employed to simultaneously sample the Talbot images at various distances along a direction perpendicular to the grating. Spectral information of the incident light can be calculated by taking Fourier transform of the measured Talbot images or by comparing the measured Talbot images with a library of intensity patterns acquired with light sources having known wavelengths.

Systems and methods are disclosed for generating hyperspectral images, which may correspond to a three dimensional image in which two dimensions correspond to a spatial field of view and a third dimension corresponds to a frequency domain absorption spectrum. Disclosed systems and methods include those employing dual optical frequency comb Fourier transform spectroscopy and computational imaging for generation of hyperspectral images. Such a combination advantageously allows for imaging systems to exhibit low size, weight, and power, enabling small or handheld sized imaging devices.

A spectrometer for detecting one or more wavelength components of sample radiation is disclosed. The spectrometer includes: a detector comprising a two-dimensional rectilinear array of pixels for generating signals representing an image based on collected sample radiation; one or more optical components arranged to form a spatial pattern based on spectral features of the sample radiation the spatial pattern including a plurality of aligned substantially parallel fringes oriented at a non-zero skew angle to the two-dimensional rectilinear array; and an analyser arranged to receive the signals and provide an output related to the one or more wavelengths. The spectrometer suppresses column/row noise in the detector. Also disclosed is a method of suppressing noise when signals are extracted and processed from detector arrays.

A spectral imager, including: a photodetector including a plurality of photosensitive sites exposed on a photosensitive surface; a collimating lens including an intermediate focal plane; an array of interferometers including two main waves, each including a cavity defined by two faces; an array of microlenses arranged in a plane parallel to the photosensitive surface, each microlens paired with an interferometer to form an optical pair, including an image focal plane coinciding with the photosensitive surface and facing a section of the photosensitive surface.

[Object] The object of the invention is to present a new spectral measurement technique enabling a measurement even if light to be measured exists within a very short period.

[Means for Solution] A broadband pulsed light wave L1 where wavelength shifts temporally and continuously in a pulse interferes with a light wave L0 to be measured. The intensity at each wavelength of the light wave L0 to measured is obtained by the Fourier transform of the output signal from a detector 5 that has detected the intensity of the wave resultant from the interference. A laser beam L2 from a laser source 1 is converted to a supercontinuum wave L3 by a nonlinear optical element 2. A pulse extension element 3 extends pulses of the supercontinuum wave L3, thus generating the broadband pulsed light wave L1.

A reconstruction matrix used for calculating a hyperspectral data-cube includes rows of periodic functions. Each row of the reconstruction matrix corresponds to a selected wavelength and each column corresponds to a selected retardance of an interferometer. The periodic functions have as a parameter the selected wavelength of the corresponding row and are sampled at the selected retardances of each of the corresponding columns. An interferogram data-cube is obtained and includes an array of one or more simultaneously measured interferograms. Each row of the interferogram data-cube corresponds to one of the selected retardances and each column corresponds to a different interferogram from the simultaneously measured interferograms. A set of matrix-vector products for each of the interferograms is formed by multiplying the reconstruction matrix with a column of the interferogram data-cube to form the hyperspectral data-cube.