An optical system includes an optical element and an optical filter with a first set of channels and a second set of channels respectively associated with a first region and a second region of the optical filter. The optical element causes first light beams and second light beams associated with a subject to respectively fall incident on the first region within a first incidence angle range and on the second region within a second incidence angle range. A first channel, of the first set of channels, passes, based on the first incidence angle range, a set of the first light beams that are associated with a first subrange of a particular wavelength range. A second channel, of the second set of channels, passes, based on the second incidence angle range, a set of the second light beams that are associated with a second subrange of the particular wavelength range.

An optical system includes an optical element and an optical filter with a first set of channels and a second set of channels respectively associated with a first region and a second region of the optical filter. The optical element causes first light beams and second light beams associated with a subject to respectively fall incident on the first region within a first incidence angle range and on the second region within a second incidence angle range. A first channel, of the first set of channels, passes, based on the first incidence angle range, a set of the first light beams that are associated with a first subrange of a particular wavelength range. A second channel, of the second set of channels, passes, based on the second incidence angle range, a set of the second light beams that are associated with a second subrange of the particular wavelength range.

A multiband IR adjunct (MIRA) sensor to spectroscopically determine the content and the concentration of chemical composition of a targeted object, includes a sensor housing, a first front optics in a first optical channel, a second front optics in the first optical channel, an acousto-optic tunable filter (AOTF), a photo detector (PD), a set of back optics in the first optical channel that focuses polarized narrow-band light beams received from the AOTF device onto the PD, the PD converting the polarized narrow-band light beams into an electrical signal, and a data acquisition unit signal-connected to the PD, the data acquisition unit collecting the electrical signals. Multiple optical channels can be provided within the housing to analyze UV/VIS/near infrared (NIR), short-wavelength infrared (SWIR), mid-wavelength infrared (MWIR), and LWIR wavelength ranges respectively.

A device may include a sensor window. The sensor window may include a substrate. The sensor window may include a set of layers disposed onto the substrate. The set of layers may include a first subset of layers of a first refractive index and a second set of layers of a second refractive index different from the first refractive index. The set of layers may be associated with a threshold transmissivity in a sensing spectral range, and may be configured to a particular color in a visible spectral range and associated with a threshold opacity in the visible spectral range. The device may include a spectral sensor device aligned to the sensor window and including at least one sensor element to receive light in the sensing spectral range and provide a plurality of sensing functionalities based on at least one measurement of the light in the sensing spectral range.

A spectroscopic camera includes: a spectral filter having an optical area that transmits light with a predetermined wavelength from incident light; an image sensor receiving transmitted light transmitted through the spectral filter; and a casing accommodating the spectral filter and the image sensor. A direction in which the incident light enters is a first direction. The casing includes: a cylindrical lens mount which a lens that the incident light enters is attachable to and removable from and which has a center axis along the first direction; a wall having an aperture that has an aperture center coaxial with the center axis of the lens mount and that is smaller than a cylindrical inner diameter of the lens mount and equal to or smaller than an outer diameter of the optical area; a filter accommodation unit accommodating the spectral filter at such a position that the optical area covers the aperture, as viewed in a plan view along the first direction; and an imaging sensor accommodation unit provided downstream of the filter accommodation unit in the first direction and accommodating the image sensor at such a position that the image sensor overlaps the aperture as viewed in the plan view.

A spectroscopic camera includes: a spectral filter having an optical area that transmits light with a predetermined wavelength from incident light; an image sensor receiving transmitted light transmitted through the spectral filter; and a casing accommodating the spectral filter and the image sensor. A direction in which the incident light enters is a first direction. The casing includes: a cylindrical lens mount which a lens that the incident light enters is attachable to and removable from and which has a center axis along the first direction; a wall having an aperture that has an aperture center coaxial with the center axis of the lens mount and that is smaller than a cylindrical inner diameter of the lens mount and equal to or smaller than an outer diameter of the optical area; a filter accommodation unit accommodating the spectral filter at such a position that the optical area covers the aperture, as viewed in a plan view along the first direction; and an imaging sensor accommodation unit provided downstream of the filter accommodation unit in the first direction and accommodating the image sensor at such a position that the image sensor overlaps the aperture as viewed in the plan view.

An optical sensor device, includes an optical sensor that has a set of sensor elements, an optical filter that includes a plurality of regions, and one or more processors. A region, of the plurality of regions, includes a first set of optical channels comprising optical channels that are configured to pass light associated with respective subranges of a first wavelength range, a second set of optical channels comprising optical channels that are configured to pass light associated with respective subranges of a second wavelength range, and a third set of optical channels comprising optical channels that are configured to pass light associated with respective subranges of a third wavelength range. The one or more processors are configured to obtain, from the optical sensor, sensor data associated with a scene and determine image information associated with the scene based on the spectral information.

An optical signal detection system includes: a nonlinear converter that nonlinearly converts a plurality of first optical signals into a plurality of second optical signals, and also a third optical signal into a fourth optical signal; a spectrometer that obtains each of a plurality of first spectral data items from a different one of the plurality of second optical signals, and also a third spectral data item from the fourth optical signal; and a detection device that detects the third optical signal and outputs a detection result. The detection device includes: an analyzer that performs sparse principal component analysis on the plurality of first spectral data items to generate a plurality of second spectral data items; and a detector that compares the third spectral data item with each of the plurality of second spectral data items, and detects the third optical signal based on the result of the comparison.

An optical signal detection system includes: a nonlinear converter that nonlinearly converts a plurality of first optical signals into a plurality of second optical signals, and also a third optical signal into a fourth optical signal; a spectrometer that obtains each of a plurality of first spectral data items from a different one of the plurality of second optical signals, and also a third spectral data item from the fourth optical signal; and a detection device that detects the third optical signal and outputs a detection result. The detection device includes: an analyzer that performs sparse principal component analysis on the plurality of first spectral data items to generate a plurality of second spectral data items; and a detector that compares the third spectral data item with each of the plurality of second spectral data items, and detects the third optical signal based on the result of the comparison.

A spectral filter may include a plurality of filter arrays each including a plurality of unit filters having different center wavelengths from each other. Each of the plurality of unit filters may include a first metal reflection layer and a second metal reflection layer which are disposed to be apart from each other; a cavity including a first pattern and being arranged between the first metal reflection layer and the second metal reflection layer; and a lower pattern film being disposed under the first metal reflection layer and including a second pattern. In unit filters having a same center wavelength in each of the plurality of unit filters corresponding to the plurality of filter arrays, the first pattern of the cavity and the second pattern of the lower pattern film may vary according to a position of the unit filters.