A camera system includes one or more spectral illuminators, a tunable optical filter, and a sensor array. Active spectral light emitted from the one or more spectral illuminators towards a scene is dynamically tuned to an illumination sub-band selected from a plurality of different illumination sub-bands. Sequentially for each of a plurality of fluorescing light sub-bands different than the selected illumination sub-band, the tunable optical filter is adjusted to block light from being transmitted from the scene to the sensor array in all but a tested fluorescing light sub-band from the plurality of different fluorescing light sub-bands, and the sensor array is addressed to acquire one or more image of the scene in the tested fluorescing light sub-band.

Systems and methods for forming a compact gas sensor include a multilayer etalon as a wavelength discriminating element. The position of the etalon may be adjusted to tune its transmission profile. And embodiment directed to carbon dioxide detection is described.

A device for improving the suppression of light from a Pulsed Xenon light source for spectrometry by combining a Variable Longpass Order-Sorting filter with a Dichroic Balancing filter coated on a fused Silica substrate is disclosed.

An optical filter may comprise a first pair of mirrors, a second pair of mirrors, and a common spacer. The second pair of mirrors and the first pair of mirrors may reflect different portions of an electromagnetic spectrum. The common spacer may be positioned between the first pair of mirrors and between the second pair of mirrors.

The present disclosure relates to a method and a system for quantifying a biomarker of a biological tissue. Two spectral sub-intervals are determined from a plurality of images of the tissue acquired at discrete wavelengths within a main wavelength interval using an imaging sensor in a manner such that the combination of the image data in the at least two spectral sub-intervals are correlated with a clinical variable of interest. The tissue is illuminated using one or more light sources with wavelengths within the at least two spectral sub-intervals. A measurement is of the light reflected by the tissue is acquired using an imaging sensor; and a measure of the biomarker of the tissue is calculated using the acquired measurement. The main wavelength interval is broader than each of the at least two spectral sub-intervals and at least one spectral confounder causing a spectral variability of the acquired image is present in the tissue.

Imaging systems and methods for imaging using the same color or monochromatic image sensor, wherein imaging can be switched between at least two imaging modes, for example between a visible imaging mode and an IR imaging mode, without moving any system component from a given position in an optical path between an imaged object and the image sensor. In an example, a system includes an image sensor, a tunable spectral filter and a multi-bandpass filter, the tunable spectral filter and the multi-bandpass filter arranged in a common optical path between an object and the image sensor, and a controller configured and operable to position the tunable spectral filter in a plurality of operation states related to a plurality of imaging modes.

Conventionally, wavelength locking and monitoring has been achieved used various components, including calibrated etalon filters, gratings, and arrays of color filters, which offer fairly bulky solutions that require complicated controls. An improved on-chip wavelength monitor comprises: a combination comb filter comprising a plurality of comb filters, each for receiving a test beams, and each comb filter including a substantially different FSR, e.g. 10 to 20 the next closest FSR. A controller dithers a phase tuning section of each comb filter to generate a maximum or minimum output in a corresponding photodetector indicative of the wavelength of the test signal.

A camera system includes one or more spectral illuminators, a tunable optical filter, and a sensor array. Active spectral light emitted from the one or more spectral illuminators towards a scene is dynamically tuned to an illumination sub-band selected from a plurality of different illumination sub-bands. Sequentially for each of a plurality of fluorescing light sub-bands different than the selected illumination sub-band, the tunable optical filter is adjusted to block light from being transmitted from the scene to the sensor array in all but a tested fluorescing light sub-band from the plurality of different fluorescing light sub-bands, and the sensor array is addressed to acquire one or more image of the scene in the tested fluorescing light sub-band.

A Multichromatic Calibration (MC) method of at least a spectral sensor which is one of a list comprising at least a spectrometer, a multispectral sensor, a hyperspectral sensor, a spectral camera, a color camera. The method comprises a. generating a plurality of different multichromatic spectra, wherein i. a spectrum from the plurality of different multichromatic spectra contains light intensity measurable by the at least one spectral sensor and by a reference spectral device, and ii. a spectrum from the plurality of different multichromatic spectra contains light centered around at least two different wavelengths and is configured to be integrated during an exposure time of a single measurement from any of the at least one spectral sensor or the reference spectral device; b. measuring each multichromatic spectrum of the plurality of different multichromatic spectra with the reference spectral device and the at least one spectral sensor; and from all data of the measured multichromatic spectra, compute a transfer function which relates a response of the at least one spectral sensor to a corresponding response of the reference spectral device, without measuring the spectral response of the at least one spectral sensor.

Various embodiments disclosed herein describe an infrared (IR) imaging system for detecting a gas. The imaging system can include an optical filter that selectively passes light having a wavelength in a range of 1585 nm to 1595 nm while attenuating light at wavelengths above 1600 nm and below 1580 nm. The system can include an optical detector array sensitive to light having a wavelength of 1590 that is positioned rear of the optical filter.