The benefits of car night vision systems that enable drivers to see people or animals more clearly on dark, unlit roads have already started appearing in luxury cars.
But these systems rely on near-infrared (NIR) radiation, which requires the cars to be fitted with infrared headlights to illuminate the road ahead. Falling into the “thermal imaging region”, Long-wavelength (LWIR) cameras require no such external light source but the sensors require constant cooling, adding to the cost and complexity of such devices. Researchers have now developed a new type of detector which functions at room temperature allowing it to be used in cars and other mobile applications.
Objects at roughly body temperature are luminous in the infrared region at a wavelength of around ten micrometers. Unfortunately infrared cameras for the wavelength range above five micrometers like it cold – the sensor has to be constantly cooled down to about minus 193 degrees Celsius (minus 315 Fahrenheit). Although uncooled imagers for the LWIR range do already exist, they are mainly used by the military. That is set to change with researchers at the Fraunhofer Institute for Microelectronic Circuits and Systems (IMS) in Duisburg having succeeded in producing an imaging sensor for the LWIR range that functions at room temperature.