Apparatus and methods for performing optical analyses in a harsh environment are disclosed. Some of the systems and methods of the present disclosure include fluorescence, absorption, and reflectance detection using a drum spectrometer. Other systems and methods of the present disclosure include a measurement channel and a parallel reference channel concurrently filtering optical signals.

A hybrid spectral imager apparatus has an imaging head arrangement (IHA), a control and processing unit (CPU), and a display. The IHA includes an optical imager, multiband filtering optics (MBFO), and a sensor arrangement. The optical imager collects and focuses an image of a target scene or object along an imaging path. The multiband optics includes a beam divider for generating at least two replica images of the target image, and a multiband filter (MF) interposed into the imaging path and effecting multi-bandpass filtering in the image replicas. The sensor arrangement has at least one Mosaic filter array (MFA) focal plane array (FPA) sensor onto which the multiband filtered image replicas are focused, and a focal plane array masked, in a pixelized manner, with at least three wide-band primary color-type filters, with each primary color-type response separating and capturing one single-band. The CPU is coupled to the IHA and is configured to execute program instructions for calibrating image acquisition processes, controlling and synchronizing the acquisition/capturing of the image replicas by the MFA sensor arrangement, and spectrally purifying the MFA sensor arrangement responses to compensate band cross-talking between the MFA and the MF. The display is configured to display on a user interface at least the acquired single-band images. The CPU is further configured to reconstruct and display, on the display, a set of at least three different single-band images per MFA-FPA sensor employed. The IHA is configured to capture sets of different single-band images for video snapshot spectral imaging at desired spectral bands within the FPA sensor arrangement spectral sensitivity range.

A light modulation device and a single-channel spectrum detection system are provided. The light modulation device includes: a light guide plate; a dispersing component configured to disperse received light into light of different wavelengths and to diffract the light of different wavelengths into the light guide plate at different angles; and a dynamic filtering component configured to prevent light of a selected wavelength in the light guide plate from entering the dynamic filtering component such that the light of the selected wavelength emits out from the light guide plate, and to make light of non-selected wavelengths in the light guide plate enter the dynamic filtering component such that the light of the non-selected wavelengths is filtered out from the light guide plate.

A system for processing Raman scattering light from a sample is provided. The system includes a source, a digital mirror device (DMD), a detector, and an analyzer. The DMD is configured to reflect Raman scattering light and includes micromirrors selectively controllable between ON and OFF states. The detector is configured to detect Raman scattering light and to produce signals representative of the Raman scattering light. The analyzer is in communication with the light source, the DMD, the detector, and a memory storing instructions, which instructions when executed cause the processor to: a) control the light source to produce a beam of light for interrogating the sample; b) control the DMD to place in an ON or OFF state based on one or more known spectral shapes stored in the memory; and c) process the Raman scattering light reflected by the micromirrors in the ON state.

An infrared spectrometer for operation in the mid-infrared spectral range is disclosed, where the spectrometer includes a Bragg-mirror-based spectral filter that is operative for providing an output optical signal whose spectral content is spatially dispersed along a first direction, where the Bragg mirrors include low-refractive-index layers comprising a polymer material that is transmissive across the mid-infrared spectral range and is characterized by less than ten absorption peaks with the operating spectral range of the spectrometer.

A photodetection device includes: a filter array including a plurality of filters arranged in a two-dimensional array, the plurality of filters including a first filter and a second filter, the first filter and the second filter each including a first reflective layer, a second reflective layer, and an intermediate layer between the first reflective layer and the second reflective layer and having a resonant structure having a plurality of resonant modes differing in order from each other, at least one selected from the group consisting of a refractive index and a thickness of the intermediate layer of the first filter being different from the at least one selected from the group consisting of a refractive index and a thickness of the intermediate layer of the second filter; and an image sensor disposed at a position where the image senor receives light having passed through the filter array.

The present invention is a camera with video-rate acquisition and processing for medical imaging applications. In particular, the invention is used to determine the health of a body area by quantitatively measuring blood oxygen levels and melanin content from a real-time video image of a body segment. In certain embodiments, a camera comprises an objective lens; a filter tray located at an aperture stop of the objective lens, wherein the filter tray comprises a plurality of elements, each element passes a spectral band of light; a micro-lens array located at an exit pupil of the objective lens comprising a plurality of micro lenses to form an image plane, wherein the objective lens produces a focused image at the image plane; and a focal plane array comprising a plurality of sensors, wherein each sensor receives light from at least one micro-lens of the micro-lens array.

A hybrid spectral imager apparatus has an imaging head arrangement (IHA), a control and processing unit (CPU), and a display. The IHA includes an optical imager, multiband filtering optics (MBFO), and a sensor arrangement. The optical imager collects and focuses an image of a target scene or object along an imaging path. The multiband optics includes a beam divider for generating at least two replica images of the target image, and a multiband filter (MF) interposed into the imaging path and effecting multi-bandpass filtering in the image replicas. The sensor arrangement has at least one Mosaic filter array (MFA) focal plane array (FPA) sensor onto which the multiband filtered image replicas are focused, and a focal plane array masked, in a pixelized manner, with at least three wide-band primary color-type filters, with each primary color-type response separating and capturing one single-band. The CPU is coupled to the IHA and is configured to execute program instructions for calibrating image acquisition processes, controlling and synchronizing the acquisition/capturing of the image replicas by the MFA sensor arrangement, and spectrally purifying the MFA sensor arrangement responses to compensate band cross-talking between the MFA and the MF. The display is configured to display on a user interface at least the acquired single-band images. The CPU is further configured to reconstruct and display, on the display, a set of at least three different single-band images per MFA-FPA sensor employed. The IHA is configured to capture sets of different single-band images for video snapshot spectral imaging at desired spectral bands within the FPA sensor arrangement spectral sensitivity range.

Systems for and methods for in situ optimization of tunable light emitting diode sources are disclosed herein. During operation, the systems and methods obtain real-time feedback from an image sensor, and that feedback is used to tune the tunable LEDs. By tuning the tunable LEDs, the best values for the LED spectral output can be selected based on the feedback from the image sensor, and an image with improved contrast is obtained. Alternatively, the amount of time to obtain an image with acceptable contrast is reduced.

Disclosed are methods of fabricating an integrated computational element for use in an optical computing device. One method includes providing a substrate that has a first surface and a second surface substantially opposite the first surface, depositing multiple optical thin films on the first and second surfaces of the substrate via a thin film deposition process, and thereby generating a multilayer film stack device, cleaving the substrate to produce at least two optical thin film stacks, and securing one or more of the at least two optical thin film stacks to a secondary optical element for use as an integrated computational element (ICE).