Fourier Transformation Spectrometer, FT Spectrometer, comprising: Michelson-Type Interferometer (601, 602, 603, 604, 605, 606, 607, 608, 609) comprising: at least one beam splitter unit designed to split an incident light beam (EB) of a spatially expanded object into a first partial beam (TB1) and a second partial beam (TB2); and for at least partially overlaying the first partial beam (TB1) and the second partial beam (TB2) with a lateral shear (s); a first beam deflection unit designed to deflect the first partial beam (TB1) at least once; a second beam deflection unit designed to deflect the second partial beam (TB2) at least once; wherein at least one among the first beam deflection unit and the second beam deflection unit represents a (2n+1) periscope group with (2n+1) mirror surfaces, and all (2n+1) mirror surfaces are arranged vertically in relation to a common reference plane, in order to respectively deflect the first partial beam (TB1) and/or the second partial beam (TB2) (2n+1) times, and wherein the (2n+1)-fold deflection generates the lateral shear (s) between the first partial beam (TB1) and the second partial beam (TB2), and wherein n is a natural number ≥1.

An optical coherence tomography (OCT) engine includes a digital Fourier-Transform (dFT) spectrometer, a tunable delay line, and a high-speed optical phased array (OPA) scanner integrated onto a single chip. The broadband dFT spectrometer offers superior signal-to-noise ratio (SNR) and fine axial resolution; the tunable delay line ensures large imaging depth by circumventing sensitivity roll-off; and the OPA can scan the beams at GHz rates without moving parts. Unlike conventional spectrometers, the dFT spectrometer employs an optical switch network to retrieve spectral information in an exponentially scaling fashion—its performance doubles with every new optical switch added to the network. Moreover, it also benefits from the Fellgett's advantage, which provide a significant SNR edge over conventional spectrometers. The tunable delay line balances the path length difference between the reference and sample arms, avoiding any need to sample high-frequency spectral fringes.

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.

An optical module includes a micro spectrometer. The micro spectrometer includes an optical crystal, a lens, and a photosensitive assembly. The optical crystal is configured to receive detection light and covert the detection light into interference light. The optical crystal is surrounded by a sleeve, the sleeve configured to fix a position of the optical crystal. The lens is configured for receiving the interference light and focusing the interference light. The photosensitive assembly is configured for imaging the interference light into an interference image. The optical module further comprises a controller. The controller is electrically connected to the photosensitive assembly, and the controller is used to convert the interference image into light wavelength signals and light intensity signals.

A photonic integrated circuit (PIC) for determining a wavelength of an input signal is disclosed. The PIC comprises: a substrate; a first Mach-Zehnder Interferometer (MZI) disposed over the substrate, comprising first optical waveguides having a first optical path length difference, and configured to receive a first output optical signal from a light source. The PIC also comprises a second Mach-Zehnder Interferometer (MZI) disposed over the substrate, comprising second optical waveguides having a second optical path length difference, which is greater than the first optical path length difference, and configured to receive a second output optical signal from the light source.

The present application relates to a system for performing time-resolved interferometric spectroscopy of incoming light. In some embodiments, the system includes one or more optical elements, a photo-detector, a capacitance detector, and one or more processors. Upon application of a varying input signal to the one or more optical elements, a change to an optical characteristic is caused resulting in a changing interference pattern produced by the incoming light incident on the one or more optical elements. During the application of the varying input signal, the photo-detector may detect an intensity of light output from the one or more optical elements and the capacitance detector may detect a capacitance of the one or more optical elements.

A hyperspectral imaging apparatus based on a monolithic or free space optical spatial heterodyne spectrometer (SHS) design, array detector, electromagnetic radiation source, and optical collection element is described. The apparatus enables the simultaneous acquisition of spatially isolated Fizeau fringe patterns, each having an encoded light product that is decoded to produce a spectral fingerprint of the interrogated object. Features specific to the SHS, such as a large entrance aperture, large acceptance angle, and no moving parts, enable a variety of optical collection schemes including lens arrays, solid-core and hollow core waveguides, and others. In one example, a microlens array (MLA) is configured with the hyperspectral imaging apparatus to simultaneously image many hundred spatially isolated Fizeau fringe patterns while interrogating an object using an electromagnetic radiation source. Each Fizeau fringe pattern recorded by the array detector is decoded to produce a full Raman or laser-induced breakdown spectroscopy (LIBS) spectrum. Compared to prior art, the hyperspectral imaging apparatus overcomes the primary limitations of needing to trade time resolution for both spectral and spatial data density because the imaging apparatus simultaneously acquires both spectral and special information. Based on the selection and configuration of diffraction gratings, the grating aperture size, Littrow wavelength (i.e., heterodyne wavelength), and optical collection configuration, the apparatus can be tailored to produced low or high spectral resolution with a spectral bandpass that covers a portion or the entire Raman spectral range (up to 4200 cm.sup.−1) and for LIBS as well.

A method for generating a illumination dual-comb signal that provides a low frequency train of interferograms (180) readable by a regular video-rate camera (160) comprising N pixels and a sampling frequency of V Hz to extract hyperspectral information (170), the method comprising providing a monochromatic signal, splitting the monochromatic signal in two split monochromatic signals, frequency shifting each monochromatic signal with an offset frequency below

[00001]$\frac{V}{2}\mathrm{Hz},$

generating two frequency combs having a difference in repetition below

[00002]$\frac{V}{2}\mathrm{Hz}$

by a nonlinear modulation of the two split monochromatic signals, generate the illumination dual-comb signal, Illuminating a target and employing a video-rate camera (160) to read a low frequency train of interferograms (180) based on a reflected and/or transmitted signal of the illumination dual-comb signal and performing Fourier transformation of the low frequency train of interferograms (180) detected by each pixel from the N pixels to extract the hyperspectral information (170).

A method of operating a hyperspectral imaging device includes connecting electrodes on a liquid crystal variable retarder to a voltage source, rotating liquid crystal material in the liquid crystal variable retarder between a first orientation with a certain optical phase delay and a second orientation with a different optical phase delay, receiving a beam of light at an image sensor that has passed through the liquid crystal variable retarder, and producing an output signal from the image sensor.

An interference imaging device includes a light interference generator that includes: a light wave splitter configured to reflect a part of incident light and to allow a remaining part of the incident light to pass through; a phase modulator configured to modulate a phase of incident light that has passed through the light wave splitter; and a reflector configured to reflect the phase-modulated incident light from the phase modulator so that the reflected, phase-modulated incident light overlaps with incident light that has been reflected by the light wave splitter.