A protective sheath having a closed end and an open end is sized to receive a hand held spectrometer. The spectrometer can be placed in the sheath to calibrate the spectrometer and to measure samples. In a calibration orientation, an optical head of the spectrometer can be oriented toward the closed end of the sheath where a calibration material is located. In a measurement orientation, the optical head of the spectrometer can be oriented toward the open end of the sheath in order to measure a sample. To change the orientation, the spectrometer can be removed from the sheath container and placed in the sheath container with the calibration orientation or the measurement orientation. Accessory container covers can be provided and placed on the open end of the sheath with samples placed therein in order to provide improved measurements.

A method for determining surface characteristics of an intraoral structure may include illuminating an intraoral structure with light of a first light source passing through focusing optics and capturing depth image data during the illumination with the first light source of light from the intraoral structure passing through the focusing optics. The method may also include illuminating the intraoral structure with a second light source and capturing two-dimensional image data during the illumination with the second light source. Depth data of the intraoral structure may be generated using the depth image data and the two-dimensional image data may be mapped to the depth data.

A multispectral sensor array can include a combination of ranging sensor channels (e.g., LIDAR sensor channels) and ambient-light sensor channels tuned to detect ambient light having a channel-specific property (e.g., color). The sensor channels can be arranged and spaced to provide multispectral images of a field of view in which the multispectral images from different sensors are inherently aligned with each other to define an array of multispectral image pixels. Various optical elements can be provided to facilitate imaging operations. Light ranging/imaging systems incorporating multispectral sensor arrays can operate in rotating and/or static modes.

An optical assembly is disclosed including two laterally variable bandpass optical filters stacked at a fixed distance from each other, so that the upstream filter functions as a spatial filter for the downstream filter. The lateral displacement may cause a suppression of the oblique beam when transmission passbands at impinging locations of the oblique beam onto the upstream and downstream filters do not overlap. A photodetector array may be disposed downstream of the downstream filter. The optical assembly may be coupled via a variety of optical conduits or optical fibers for spectroscopic measurements of a flowing sample.

Apparatuses, systems, and methods for Raman spectroscopy are described. In certain implementations, a spectrometer is provided. The spectrometer may include a plurality of optical elements, comprising an entrance aperture, a collimating element, a volume phase holographic grating, a focusing element, and a detector array. The plurality of optical elements are configured to transfer the light beam from the entrance aperture to the detector array with a high transfer efficiency over a preselected spectral band.

A device for determining the surface topology and associated color of a structure, such as a teeth segment, includes a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associate color of a structure is also provided.

A system for determining the surface topology and associated color of at least a portion of a three-dimensional structure includes a hand-held device. A scanning system may be configured to provide depth data of the portion. An imaging system may be configured to provide two-dimensional color image data of the portion associated with the plurality of data points. A processor may be operably coupled to the hand-held device and configured to associate the depth data with the color image data.

An optical detector is provided with multiple light sources having distinct spectral characteristics, which are controlled on/off across a range of lighting intensity combinations. A measurement sensor receives radiated light that is reflected from a target surface via confined optical channels, and generates representative output signals. A local controller or a remote computing device receives the output signals or corresponding messages from the optical detector, and generates a low resolution spectral data set based on the signals for each of the lighting intensity combinations. The low resolution spectral data set is interpolated based on machine learning algorithms trained with high resolution data from a reference device to generate a high resolution spectral data set associated with the target surface. In an embodiment, an auxiliary sensor measures light reflected from one or more light sources, wherein output signals from the measurement sensor are normalized to output values from the auxiliary sensor.

A multispectral sensor array can include a combination of ranging sensor channels (e.g., LIDAR sensor channels) and ambient-light sensor channels tuned to detect ambient light having a channel-specific property (e.g., color). The sensor channels can be arranged and spaced to provide multispectral images of a field of view in which the multispectral images from different sensors are inherently aligned with each other to define an array of multispectral image pixels. Various optical elements can be provided to facilitate imaging operations. Light ranging/imaging systems incorporating multispectral sensor arrays can operate in rotating and/or static modes.

A device for determining the surface topology and associated color of a structure, such as a teeth segment, includes a scanner for providing depth data for points along a two-dimensional array substantially orthogonal to the depth direction, and an image acquisition means for providing color data for each of the points of the array, while the spatial disposition of the device with respect to the structure is maintained substantially unchanged. A processor combines the color data and depth data for each point in the array, thereby providing a three-dimensional color virtual model of the surface of the structure. A corresponding method for determining the surface topology and associate color of a structure is also provided.