At Fraunhofer Institute for Microelectronic Circuits and Systems IMS, research scientists have developed a long-wave infrared imaging sensor that can function at normal room temperature.
According to Dirk Weiler, an IMS scientist, Fraunhofer-Gesellschaft could be the first to roll out this innovative technology in Germany. Initial tests have proven successful and several infrared images have been created with the new sensor.
Common infrared cameras, for a wavelength over five micrometers, can operate only in temperatures around 193°C. They need to be constantly cooled to provide proper imaging. Although long-wave infrared range cameras that do not need to be cooled also exist, they are widely used for military applications and almost nonexistent in the European markets.
Infrared cameras are embedded with the Infrared Focal Plane Array sensor, a temperature-sensitive device, known as microbolometers, that absorbs infrared light from a distance. An array is formed when various microbolometers are combined together. Objects at body temperature are illuminated when they come within a 10 ìm wavelength in the infrared region. The sensor in the camera, affected by the thermal, locates heat source of heat, enabling the microbolometer to absorb light from this source and produce a digital signal though a readout chip. This technology enables drivers to identify objects on foggy roads before their headlights pick it up.
Standard infrared cameras first translate the electrical into an analog signal, after which digitization takes place on the analog/digital converter. The new imaging sensor features a sigma-delta converter, which enables the device to produce a digital signal without the need directly of an intermediate step.
As cooling is not required, infrared cameras are no more restricted to automotive applications. Mobile infrared cameras have potential to be deployed in firefighting applications to locate people or identify hidden hotspots in buildings filled with smoke.