Spectroscopy & Microscopy

Spectroscopy & Microscopy

What is spectroscopy?

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.

What is microscopy?

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. 

What is spectroscopy used for?

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.

What do we offer?

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.

What is microscopy used for?

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.

What do we offer?

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.

What features are needed?

  • SWIR wavelength range
    InGaAs detectors are sensitive in the 0.9 - 1.7 μm SWIR band.
  • LWIR wavelength range
    Uncooled microbolometer or MCT detectors are sensitive in the 8 - 12 μm LWIR band.
  • Extended SWIR wavelength range
    SWIR InGaAs detectors can be extended into the visible: 0.6 - 1.7 μm band; other SWIR detectors operate in the 0.9 - 2.35 μm band.
  • High image resolution
    The amount of pixels has a huge impact on the image. The higher the resolution, the more detail your image contains
  • Small pixel size
    A smaller pixel size results in smaller detectors - resulting in lower sensor production costs, smaller optics and eventually smaller cameras
  • Pixel shape
    In some spectroscopy systems rectangular pixels are needed. We offer both square and rectangular pixels for linescan SWIR InGaAs arrays
  • High frame rate
    High frame rates allow us to capture fast moving objects
  • High line rate
    High line rates allow us to capture fast moving objects
  • Low noise level and high dynamic range
    A low noise level assures a high sensitivity, while a high dynamic range results in a high image contrast
  • Filter mount options
    We offer SWIR linescan cameras that have an optional filter holder for a band-pass filter
  • Sensor temperature stabilization or cooling
    A cooled SWIR camera has a lower dark current, reaches lower noise levels and has a higher dynamic range. Several SWIR cameras in our product range are TE1-stabilized, TE1-cooled, TE3-cooled or TE4-cooled

Are you looking for more information? 

Let us know. We are happy to help.

Contact us


Application notes
Imaging spectroscopy with SWIR InGaAs cameras has multiple applications in all sorts of industries Image capture in the near-infrared spectrum (NIR) at wavelengths up to 2.5 μm is gaining ever greater economic significance. This is especially true in regard to imaging spectroscopy: hyperspectral microscopes, for example, can accelerate the design process of new kinds of LED structures; multispectral online inspection of recyclable materials ensures unmixed waste separation [1]; and finally, in the arts, multispectral reflectography serves as a tool for revealing the secrets of old masters and their works.
SWIR cameras are suitable for microscopy as they operate with standard glass optics As SWIR cameras can operate with standard glass optics, they can be used with most existing microscopes
Low-noise SWIR InGaAs camera accelerates Melanoma diagnosis Dutch researchers have used the Cougar-640 to develop a cutting-edge method to accelerate the diagnosis of melanoma

World's first InGaAs camera photon emission microscope

Xenics enabled Semicaps to realize the world's first InGaAs camera photon emission microscope in 2004. Since then Xenics and sInfraRed have supported us in our endeavors for better sensitivity and resolution in photon and thermal emission microscopy.

Chua Choon Meng, CEO Semicaps