Infrared Spectroscopy

Infrared spectroscopy is a well-established and widely spread measurement technology. Due to the physical nature of the underlying sensing principle – infrared absorption of molecules – it is the technology of choice to highly selectively and stably determine concentrations of materials and compositions of mixtures of substances. InfraTec produces various detectors for analytical instruments and spectrometers.

Broadband Detectors for Laser and FTIR Spectroscopy

High-quality lithium tantalate (LiTaO3) is an extremely powerful and versatile detector material. It is not only less expensive than many other materials, e.g. deuterated triglycine sulfate (DTGS) or mercury cadmium telluride (MCT), but also exhibits outstanding temperature stability and linearity. Through a special metal black layer, InfraTec’s infrared detector absorbs radiation extremely uniformly over a very wide wavelength range from 2 µm to over 20 µm. The LiTaO3 pyroelectric detector does not require cooling nor temperature stabilization. Therefore, it ideally suits for cost-effective and robust spectrometers, especially for use outside the laboratory. Solutions based on detector materials like DTGS or MCT quickly reach their limits here. They are less suitable for such complex applications, are more prone to failure and cause higher costs.

For spectrometer applications, pyroelectric detectors can be optimized with regard to the time constants to ensure short reaction times and modulation frequencies up to a few kilohertz. Customers use our detectors in highly specialized laser spectrometers for the measurement of lowest gas concentrations down to ppb level as well as in universally usable FTIR spectrometers.

Tunable Detectors with Integrated Fabry-Pérot Filter

The employment of tunable detectors with integrated Fabry-Pérot filter (FPF) provides users with new possibilities. If you already use spectroscopy for a wide variety of analyses, you can use a Fabry-Pérot interferometer (FPI) to apply a significantly smaller component with similar functionality.

At the same time, users will be given new options, which up to now have used classic multi channel detectors in a TO8 housing and have therefore been limited to a maximum of four discrete wavelengths. Tunable detectors provide the perfect alternative for them to acquire continuous spectra with low resolution in limited spectral ranges and to realize extremely compact and cost-effective spectroscopy solutions in mid-wavelength infrared.

With tunable detectors, measurement tasks can be solved in which classic NDIR solutions such as multi channel detectors fail. An example of this are analyses in which gaseous hydrocarbons are involved. These gases have very closely spaced or overlapping absorption bands. Therefore, an NDIR measurement would require a set of extreme precisely defined narrow bandpass filters. This is achieved much more easily by the tunable filter. With its help, more gases can be differentiated by a detector. Furthermore, unknown gases can be detected with this filter.

These electrically tunable FPF are based on silicon MEMS technology. The resulting miniaturization advantage means that a TO8 housing is sufficient for the integration of a Fabry-Pérot interferometer (FPI). It contains a pyroelectric detector (FPI detector) including a signal preamplifier as well as electronics components for integrated control. This design also facilitates the adaptation of existing designs in order to arrive at new measurement solutions quickly and with little effort.

Applications of Infrared Spectroscopy

Knowing the exact composition of solids, liquids and gases is relevant under different aspects. Usually the quality and quantity of any organic and inorganic compounds are to be determined. The applications of infrared spectroscopy are correspondingly broad. The method is often used for the following purposes:

  • Environmental and climate research: measure emissions, identify plastics in waste sorting, detect leaks on supply lines, determine the composition of the atmosphere
  • Measurement on surfaces: detect contaminants, ensure complete coating with lubricants, determine the type and thickness of coatings
  • Explosive atmospheres: e.g. detect if dangerous substances in the form of gas, vapour or mist are present
  • Medical technology: monitor anaesthetic gases, capnography, determine the chemical composition of tissue by spectral measurement to detect diseases, test breath alcohol
  • Oil analysis: e. g. monitor the condition of used transmission oil
  • Food quality control: e.g. analyse the composition of food ingredients
  • Forensics: e.g. identify textile fibres, identify counterfeits
  • Pharmaceutical analysis: test newly formulated medicinal products
  • Analysis of polymers and plastics: e. g. identify compounds, identify impurities
  • Process control: e.g. monitor the compliance with material specifications
Get in contact with InfraTec sensor division

Would You Like to Know More?

It is not unusual for tasks to be associated with special requirements. Discuss your specific application needs with our experienced engineers, receive further technical information or learn more about our additional services.

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InfraTec GmbH
Infrarotsensorik und Messtechnik
Gostritzer Str. 61 – 63
01217 DresdenGERMANY
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Further Applications of FPI Detectors

  • Environmental and climate research
    - Measurement of emissions
    - Identification of plastics in waste sorting
    - Leak detection on supply lines
    - Composition of the atmosphere

  • Measurement on surfaces
    - Detect contaminants
    - Ensure complete coating with lubricants
    - Determine the type and thickness of coatings

  • Identification of solids

  • Identification of impurities or counterfeits

Find Out More About Our Pyroelectric Detectors

Detector Search

InfraTec offers five different product groups including approximately 50 standard pyroelectric detectors. Choose your suitable infrared detectors with the help of our detailed detector search.

Overview of all standard infrared detectors
Sensor division InfraTec detectors overview