In one compact housing, the Xeva-1.7-320 digital camera combines a thermo-electrically cooled InGaAs detector head and the control and communicatio
Spectroscopy is the study of the interaction between matter and reflected (or radiated) photons. In spectroscopy applications, researchers typically measure the intensity of light as a function of wavelength. The most common example of spectroscopy is the daily observations of colours by the human eye.
For wavelengths in the SWIR or LWIR range, it is called SWIR or LWIR spectroscopy. A related technique combining imaging and spectroscopy is hyperspectral imaging, or imaging spectroscopy.
SWIR cameras mounted on optical microscopes inspect micro-electronic circuits on chip or wafer level. Silicon material is transparent for SWIR photons with a wavelength longer than approximately 1100 nm. Therefore, SWIR cameras can be used to reveal defects, cracks or impurities inside the chips or wafers.
The resulting spectral data are used to detect, identify or quantify atoms or molecules of a specific material or substance. Many scientific applications exist that rely on the identification of the chemical composition of a material. Furthermore, this technique can be used in astronomy or in industrial applications such as waste sorting and food inspection.
SWIR spectroscopy typically uses line-scan InGaAs detectors, together with a spectrograph to diffract the light onto the line-scan array. For example, a SWIR array or camera with 1024 pixels will result in a spectral signal for 1024 different wavelengths. Customers typically require high sensitivity (large, usually rectangular, pixels) with good dynamic range. High spectral resolution translates into a linescan array with many pixels. We offer our Lynx SWIR TE1-cooled line-scan camera series for this application.
For SWIR imaging spectroscopy or hyperspectral imaging, a SWIR camera with two-dimensional InGaAs array is typically used, in combination with a spectrograph or tunable filter system. Customers typically require high sensitivity (low noise) with good dynamic range. For systems using a spectrograph, high spectral and spatial resolution translates into a two-dimensional array with high resolution. For hyperspectral imaging we offer our Cheetah-640CL and our TE1- or TE3-cooled Xeva-1.7-320 & Xeva-1.7-640 SWIR cameras.
Also in LWIR, imaging spectroscopy can be used. For example in mining related applications such as mineralogy or drill core inspection, where “wide-band” spectroscopy, covering visible, SWIR and LWIR are needed to classify different types of rock material. In this field our Gobi series offer the perfect solution.
For example, the production process of MEMS (Micro-Electro-Mechanical Systems) devices requires inspection through different layers of silicon. Additionally, SWIR microscopy is used to photonic circuits, to quantify losses along optical waveguides, or coupling losses on interfaces.
Another related application is optical fault localization based on photon emission microscopy. Very sensitive, cooled SWIR InGaAs cameras can detect the faint emission of faults, through the backside of the circuit.
For microscopy applications, customers are typically looking for small cameras that can easily be mounted on a microscope. Our compact SWIR cameras with C-mount optical interface allow for easy mounting on most standard microscopes. Automatic contrast enhancement, supported by our Xeneth software, can also be an important feature.