A method includes receiving collimated light from an optical imaging system and dividing the received light into multiple bands of wavelength. Each band is refocused onto a corresponding diffraction grating having an amplitude function matched to a point spread function (PSF) of the optical imaging system. The light that is not filtered out by the diffraction grating is transmitted onto a corresponding pixel array. An image is reconstructed from data provided by the pixel arrays for each band. The intensity of light scattered by each diffraction grating may be detected, with the image being reconstructed as a function of an average value of detected intensity of scattered light used to scale the known zero-order mode profile, which is added to the image on the pixel array.

A method includes receiving collimated light from an optical imaging system and dividing the received light into multiple bands of wavelength. Each band is refocused onto a corresponding diffraction grating having an amplitude function matched to a point spread function (PSF) of the optical imaging system. The light that is not filtered out by the diffraction grating is transmitted onto a corresponding pixel array. An image is reconstructed from data provided by the pixel arrays for each band. The intensity of light scattered by each diffraction grating may be detected, with the image being reconstructed as a function of an average value of detected intensity of scattered light used to scale the known zero-order mode profile, which is added to the image on the pixel array.

A spectral sensor and a method for forming the spectral sensor is disclosed. The spectral sensor includes a planar waveguide on a substrate; a restriction mechanism that restricts a range of angles of incidence of light impinging onto the chirped input coupling grating; the chirped input grating formed to couple incident light into the planar waveguide, wherein the chirped input coupling grating comprises a first transverse chirp to provide a spectrally selective coupling of incident light Into the planar waveguide; a propagation region to filter out light that is not coupled into the planar waveguide; a detector array arranged on the opposite side of the propagation region from the chirped input coupling S grating to receive light coupled out of the planar waveguide and produce output signals representative of the light; and an electrical circuit to readout output signals from the detector array.

A spectral sensor and a method for forming the spectral sensor is disclosed. The spectral sensor includes a planar waveguide on a substrate; a restriction mechanism that restricts a range of angles of incidence of light impinging onto the chirped input coupling grating; the chirped input grating formed to couple incident light into the planar waveguide, wherein the chirped input coupling grating comprises a first transverse chirp to provide a spectrally selective coupling of incident light Into the planar waveguide; a propagation region to filter out light that is not coupled into the planar waveguide; a detector array arranged on the opposite side of the propagation region from the chirped input coupling S grating to receive light coupled out of the planar waveguide and produce output signals representative of the light; and an electrical circuit to readout output signals from the detector array.

A curved diffraction grating includes a substrate and a metal layer. The substrate is a two-dimensional curved plate structure and has a first surface, a second surface and a plurality of microstructures. The first surface is disposed opposite to the second surface, and the microstructures are disposed on the second surface. Each of the microstructures is a saw-tooth structure and has a clear blazed angle. The metal layer is disposed on the microstructures and has a plurality of diffraction structures corresponding to the microstructures. A spectrometer containing the curved diffraction grating and a manufacturing method of the curved diffraction grating are also disclosed.

Provided is a hyperspectral imaging (HSI) apparatus. The HSI apparatus includes: a first slit plate configured to introduce an output beam; a first aspherical mirror configured to reflect the introduced output beam; a first grating having a planar reflective surface, the first grating configured to generate a plurality of first split beams by splitting the output beam after being reflected by the first aspherical mirror; and a first camera configured to detect the plurality of first split beams.

Provided is a hyperspectral imaging (HSI) apparatus. The HSI apparatus includes: a first slit plate configured to introduce an output beam; a first aspherical mirror configured to reflect the introduced output beam; a first grating having a planar reflective surface, the first grating configured to generate a plurality of first split beams by splitting the output beam after being reflected by the first aspherical mirror; and a first camera configured to detect the plurality of first split beams.

Provided is a spectral sensor array, including: a planar waveguide on a substrate; a chirped input coupling grating, wherein the chirped input coupling grating comprises a transverse chirp to provide a spectrally selective coupling of incident light into the planar waveguide; an output coupling grating; and an array of photodetectors arranged to receive the light coupled out of the waveguide.

Provided is a spectral sensor array, including: a planar waveguide on a substrate; a chirped input coupling grating, wherein the chirped input coupling grating comprises a transverse chirp to provide a spectrally selective coupling of incident light into the planar waveguide; an output coupling grating; and an array of photodetectors arranged to receive the light coupled out of the waveguide.

Hyperspectal imagers including reflective and transmissive metasurfaces are disclosed. The described metasurfaces are used collectively to disperse and focus light of different wavelengths and incident angles on a focal plane. The disclosed devices are compact and light, and can be used in systems and applications requiring stringent form factors.