Principle of Infrared Radiation

The principle of infrared radiation is based on the physical phenomenon that any body of a temperature above absolute zero (-273.15 °C) emits electromagnetic radiation. There is clear correlation between the surface of a body and the intensity and spectral composition of its emitted radiation. By determining its radiation intensity the temperature of an object can thereby be determined in a non-contact way.

Infrared radiation is that part of the electromagnetic spectrum that is immediately adjacent to the red light (infrared light) of approx. 760 nm on the long-wave side of the visible spectrum and extends to a wavelength of approx. 1 mm.

Advantages of Pyroelectric Infrared Detectors by InfraTec

As part of the family of thermal detectors, a pyroelectric detector, unlike semiconductor detectors (InGaAs, PbS, PbSe), are equipped with a highly efficient, absorbent black layer and thus has an extremely broad, spectrally and laterally homogeneous sensitivity. Semiconductor detectors achieve a higher specific detectivity than pyroelectric infrared detectors when operated with up to a wavelength range of 3 µm at room temperature.

Compared to thermopile detectors, which may also detect long wavelength infrared radiation at room temperature, a pyroelectric infrared detector by InfraTec is much faster and operates with significantly higher signal voltage, even without additional preamplification. Optimal conditions for pyroelectric detectors are at wavelengths between 2.5 and 25 µm and modulation frequencies 0.5 to 400 Hz.

InfraTec pyroelectric infrared detectors use special black layers for absorption and can therefore even be used as large-scale, long-term stable receivers of UV radiation (i.e. 193 nm), but can also be used for THz radiation in the range of 100 µm to 1 mm.

Infrared Detectors Offer

  • High flexibility in terms of the measurement substances
  • Application chemometric methods for multi-component analysis
  • Measurement of known compositions with overlapping bands
  • Identification of unknown substances
  • Cost-effective, robust and miniaturized solution
Comparison of different infrared detectors

The Infrared Detector in Use

The most common use of pyroelectric infrared detectors is for motion detection. Inexpensive pyroelectric ceramic sensors generally suffice for this purpose. Other applications include the non-dispersive infrared gas analysis (NDIR gas analysis) and infrared flame sensing and monitoring. In these areas, mainly high-quality, single-crystal lithium tantalate (LiTaO3) is used as a pyroelectric material. This also gives a long-term stable performance for the large signal-to-noise ratio. The use of pyroelectric infrared detectors for spectroscopy or radiometry is also possible.

Pyroelectric detectors in the NDIR gas analysis - Picture Credits: © Juergen Faelchle /
Pyroelectric Detectors in Gas Analysis

Gas Analysis

The range of applications of pyroelectric infrared detectors for gas analysis is very extensive, ranging from environmental measurements to the detection of gas leaks, steel analysis and medical patient monitoring while under anesthesia.

Infrared Flame Sensor / Infrared Flame Monitoring - Picture Credits: © ttstudio /
Infrared Flame Sensor

Infrared Flame Sensor

Use InfraTec’s fail-safe and consistently stable pyroelectric infrared detectors for detecting typical spectral radiation, which is caused by burning organic substances.



In spectroscopes, very special pyroelectric infrared detectors by InfraTec are used. Essential for this application are the uniform absorption characteristics over a wide wavelength range. This is made possible by a special absorption layer on the pyroelectric chip.

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.

United States

InfraTec infrared LLC
75024 Plano, TXUSA

Contact information

Western USA and Canada
+1 877 797 6748
Eastern USA and Canada
+1 772 940 9975

Manufacturing Excellence

All steps in development and production take place in our main building in Dresden, starting with development and simulation to design and prototyping to the volume production of detectors. Technologies are designed with redundancy and produce a complete in-house technological process. PVD, chip and wire bonding and product measurements are automated, what removes the variations of the manual manufacturing. This results in a constant high quality in all fields, even with the most demanding manufacturing and testing processes.

InfraTec pyroelectric infrared detectors use polished double sided LiTaO3 single crystals as a polyelectric material, which due to a specific process, produces very thin (25 µm), highly sensitive, low-noise pyroelectric chips in an automated batch process.

Infrared Detectors from InfraTec

Single channel detectors from InfraTec
Single Channel Detectors

Single Channel Detectors

Single-channel for gas analysis, flame detection and radiometry.

  • TO18 or TO39 housing
  • Thermal compensation
  • JFET or CMOS amplifier
Multi Channel Detectors

Multi Channel Detectors

Choice between standard planar multi channel detectors and PYROMID® detectors.

  • Dual, quad and eight channel detectors for gas analysis and flame detection
  • Individually customizable, e.g. with option for JFET, operational amplifier, integrated beam splitter, etc.
Special single channel detectors from InfraTec
Extended Detectors

Extended Detectors

Single-channel for analytical instruments and spectroscopy.

  • High performance
  • Fast response
  • Metal black coating
Tunable FPI detectors from InfraTec
Tunable Detectors (FPI)

Tunable Detectors (FPI)

Single-channel for analytical instruments and spectroscopy.

  • Electrostatic drive > 1 µm
  • Tuning range
  • Resolution (finesse) λ/ Δλup to 60

IR Filters for Infrared Detectors

On the following page you will find information about the filters integrated in our infrared detectors.

Technology Consulting and Product Management
Consulting & Product Management

Consulting & Product Management

We are happy to advise you individually and discuss possible special applications of 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