A multispectral imaging device includes: an illumination optical system; and an imaging optical system, wherein the illumination optical system includes a filter group disposed in an overlap region of bundles of illumination rays which reach points in an imaging area of a subject, and including at least a first filter and a second filter having different transmission properties, and the imaging optical system includes: an image sensor which includes at least first light receiving elements and second light receiving elements; and a separation optical element which guides light which has passed through the first filter to the first light receiving elements, and guides light which has passed through the second filter to the second light receiving elements.

Pulsed fluorescence imaging in a light deficient environment is disclosed. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation. The system includes a controller configured to synchronize timing of the emitter and the image sensor. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises electromagnetic radiation having a wavelength from about 770 nm to about 790 nm or from about 795 nm to about 815 nm.

An endoscopic imaging system for use in a light deficient environment includes an imaging device having a tube, one or more image sensors, and a lens assembly including at least one optical elements that corresponds to the one or more image sensors. The endoscopic system includes a display for a user to visualize a scene and an image signal processing controller. The endoscopic system includes a light engine having an illumination source generating one or more pulses of electromagnetic radiation and a lumen transmitting one or more pulses of electromagnetic radiation to a distal tip of an endoscope.

In a spectroscopic module, a light shielding member is disposed between a plurality of bandpass filters and a light detector. The light shielding member includes a plurality of wall portions. The plurality of wall portions are arranged along an X direction with a light passage opening interposed therebetween, each of a plurality of optical paths from the plurality of bandpass filters to a plurality of light receiving regions passing through the light passage opening. A first wall portion and a second wall portion adjacent to each other among the plurality of wall portions are in contact with the bandpass filter, the bandpass filter corresponding to the light passage opening between the first wall portion and the second wall portion. A width in a Y direction of the light passage opening is larger than a width in the Y direction of the bandpass filter.

An integrated radiation sensor for color matching functions comprises a plurality of color matching channels, each color matching channel comprising a radiation sensing element and an associated optical filter defining a spectral sensitivity profile corresponding to a color matching function. The sensors comprise a plurality of compensation channels, each compensation channel comprising a radiation sensing element and an associated optical filter defining a spectral sensitivity profile for use in compensating a color sensed by the color matching channels. The spectral sensitivity profile of each compensation channel substantially corresponds to a mean of an upper deviation spectra and a lower deviation spectra, wherein the upper deviation spectra corresponds to a spectral sensitivity profile of a typical color matching channel increased by a fixed deviation in wavelength and the lower deviation spectra corresponds to the spectral sensitivity profile of the typical color matching channel decreased by the fixed deviation in wavelength.

An optical filter includes an active filter region including at least one of a spectral filter and a polarizing filter; and a reference filter region configured to sense an amount of light passing through the active filter region, wherein the reference filter region includes a gray filter and at least one of a black filter and a transparent filter, wherein the gray filter has a transmittance that is higher than a transmittance of the black filter and lower than a transmittance of the transparent filter.

Systems and methods for filtering an optical beam are described. In one implementation, a system for filtering an input optical beam includes a first beamsplitter, a first spectral slicing module, a second spectral slicing module, and a second beamsplitter. The first beamsplitter is configured to split the input optical beam into a first optical beam and a second optical beam. The first spectral slicing module has a first passband and is configured to filter the first optical beam. The second spectral slicing module has a second passband and is configured to filter the second optical beam. The second beamsplitter is configured to combine the first optical beam and the second optical beam into an output optical beam. The first and second spectral slicing modules may each comprise a longpass filter and a shortpass filter aligned along its optical axis, and the longpass filter and/or the shortpass filter are rotatable relative to the optical axis. Advantageously, the optical system allows for tunable spectral filtering of the input optical beam suitable for 2-D imaging systems.

An optical system operating in the near or short-wave infrared wavelength range identifies an object based on water absorption. The system comprises a light source with modulated light emitting diodes operating at wavelengths near 1090 and 1440 nanometers, corresponding to lower and higher water absorption. The system further comprises one or more wavelength selective filters and a housing that is further coupled to an electrical circuit and a processor. The detection system comprises photodetectors that are synchronized to the light source, and the detection system receives at least a portion of light reflected from the object. The system is configured to identify the object by comparing the reflected light at the first and second wavelength to generate an output value, and then comparing the output value to a threshold. The optical system may be further coupled to a wearable device or a remote sensing system with a time-of-flight sensor.

An optical filtering device, in particular for remote gas detection, including a member comprising a tubular passage accommodating a plurality of reflective structures capable of reflecting infrared wavelengths, said structures being elongated along an axis of the tubular passage and arranged around the axis. The reflective structures comprise means of filtering by absorption of bands of different wavelengths located in the infrared spectral band.

A wavelength selective structure for selectively reflecting or absorbing incident electromagnetic visible or infrared radiation. The wavelength selective structure includes a wavelength selective structure with a plurality of layers, including a compound layer forming a plurality of surface elements, an electrically isolating intermediate layer, wherein the compound layer is in contact with a first surface of the electrically isolating intermediate layer, and a continuous electrically conductive layer in contact with a second surface of the electrically isolating intermediate layer. The compound layer includes at least one metallic layer and at least one dielectric layer. The selective surface has at least one resonance band for selectively reflecting or absorbing visible or infrared radiation based on a resonant electromagnetic coupling between the plurality of surface elements and the continuous electrically conductive layer.