A conventional spatial heterodyne spectrometer (SHS) comprises a beam splitter and a pair of diffraction gratings, one in each arm of the SHS. The beam splitter separates an input beam of light into first and second sub-beams for transmission to a respective diffraction grating, and then recombines the diffracted sub-beams for focusing onto a camera. A field widened SHS enables much larger range of input angles of the original beam to be focused onto the camera, so that a broader range of wavelengths may be collected. Increasing the range of wavelengths may be provided by one or more of the following: combining the beam splitter with a field widening prism, making one diffraction grating farther from the beam splitter than the other, and placing a plurality of diffraction gratings in each arm of the SHS.

A conventional spatial heterodyne spectrometer (SHS) comprises a beam splitter and a pair of diffraction gratings, one in each arm of the SHS. The beam splitter separates an input beam of light into first and second sub-beams for transmission to a respective diffraction grating, and then recombines the diffracted sub-beams for focusing onto a camera. A field widened SHS enables much larger range of input angles of the original beam to be focused onto the camera, so that a broader range of wavelengths may be collected. Increasing the range of wavelengths may be provided by one or more of the following: combining the beam splitter with a field widening prism, making one diffraction grating farther from the beam splitter than the other, and placing a plurality of diffraction gratings in each arm of the SHS.

A conventional spatial heterodyne spectrometer (SHS) comprises a beam splitter and a pair of diffraction gratings, one in each arm of the SHS. The beam splitter separates an input beam of light into first and second sub-beams for transmission to a respective diffraction grating, and then recombines the diffracted sub-beams for focusing onto a camera. A field widened SHS enables much larger range of input angles of the original beam to be focused onto the camera, so that a broader range of wavelengths may be collected. Increasing the range of wavelengths may be provided by one or more of the following: combining the beam splitter with a field widening prism, making one diffraction grating farther from the beam splitter than the other, and placing a plurality of diffraction gratings in each arm of the SHS.

A conventional spatial heterodyne spectrometer (SHS) comprises a beam splitter and a pair of diffraction gratings, one in each arm of the SHS. The beam splitter separates an input beam of light into first and second sub-beams for transmission to a respective diffraction grating, and then recombines the diffracted sub-beams for focusing onto a camera. A field widened SHS enables much larger range of input angles of the original beam to be focused onto the camera, so that a broader range of wavelengths may be collected. Increasing the range of wavelengths may be provided by one or more of the following: combining the beam splitter with a field widening prism, making one diffraction grating farther from the beam splitter than the other, and placing a plurality of diffraction gratings in each arm of the SHS.

The present disclosure resides in a spectrometer arrangement including a first dispersing element for spectral separation of radiation in a main dispersion direction, and a second dispersing element for spectral separation of radiation in a cross-dispersion direction, which is at an angle to the main dispersion direction, so that a two-dimensional spectrum is producible. The spectrometer arrangement also includes a collimating optics, which directs collimated radiation to the first and/or second dispersing element, a camera optics, which images a two-dimensional spectrum in an image plane, a two-dimensional detector for detecting the two-dimensional spectrum in the image plane, and an off-axis section of a rotationally symmetric, refractive element, which is arranged between the camera optics and the detector. The present disclosure resides likewise in an optical module comprising such a spectrometer arrangement.

The present disclosure discloses a spectrometer arrangement including an entrance-slit group including a slit wheel and a slit mask for introducing radiation into and for limiting the optical field of the spectrometer arrangement, a first dispersive element for spectrally decomposing the radiation in a main dispersion direction, and a second dispersive element for spectrally decomposing the radiation in a transverse dispersion direction that forms an angle with the main dispersion direction to yield a two-dimensional spectrum. The slit wheel is mounted rotatably about an axis of rotation and has a falcate opening having a width that changes depending on the angle. The slit mask includes an opening that is longer than a largest width of the falcate opening such that radiation radiates through the falcate opening of the slit wheel and the opening of the slit mask. The present disclosure further includes a corresponding method and an optical component group.

The present disclosure discloses a spectrometer arrangement including an entrance-slit group including a slit wheel and a slit mask for introducing radiation into and for limiting the optical field of the spectrometer arrangement, a first dispersive element for spectrally decomposing the radiation in a main dispersion direction, and a second dispersive element for spectrally decomposing the radiation in a transverse dispersion direction that forms an angle with the main dispersion direction to yield a two-dimensional spectrum. The slit wheel is mounted rotatably about an axis of rotation and has a falcate opening having a width that changes depending on the angle. The slit mask includes an opening that is longer than a largest width of the falcate opening such that radiation radiates through the falcate opening of the slit wheel and the opening of the slit mask. The present disclosure further includes a corresponding method and an optical component group.

According to certain examples a spectrometer module for use in an imaging spectrometer includes a monolithic spectrometer body component made of an immersion material and including three mirrored surfaces configured to form a reflective triplet having an optical path immersed within the immersion material, the reflective triplet configured to receive incident optical radiation from an entrance face of the monolithic spectrometer body component and reflect the incident optical radiation along the optical path, and a dispersive element configured to receive and disperse the incident optical radiation reflected from the reflective triplet to provide dispersed optical radiation. The reflective triplet is configured to receive the dispersed optical radiation from the dispersive element and to reflect the dispersed optical radiation along the optical path to an exit face of the monolithic spectrometer body component.

A freeform imaging system with a spectrometer and telescope components optically connected and optimized to increase the spectral and spatial resolution capabilities. Many embodiments of the system are capable of producing a spectral resolution of approximately 1 nm and a spatial resolution less than 30m such that the imaging system can be used to accurately capture and measure point source plumes of various atmospheric gases including CH.sub.4, CO.sub.2, CO, N.sub.2O, and H.sub.2O.

Multispectral images, including ultraviolet light and its interactions with ultraviolet light-interactive compounds, can be captured, processed, and represented to a user. Ultraviolet-light related information can be conveniently provided to a user to allow the user to have awareness of UV characteristics and the user's risk to UV exposure.