EPFL physicists propose a new path to detect infrared radiation with outstanding sensitivity, allowing detection of signals as low as that of a single quantum of light.
When using our webcam or cell phone camera, we experience the tremendous capabilities of cheap and compact sensors developed in the past decades for the visible region of the electromagnetic spectrum. On the contrary, detection of lower frequency radiation not visible to the human eye (such as mid- and far-infrared radiation) requires complex and costly equipment. Lack of a compact technology impedes widespread access to sensors for the recognition of molecules and the imaging of thermal radiation naturally emitted by our bodies. A new conceptual breakthrough in this field may therefore have tremendous impacts in our daily lives.
The most popular technique currently available to detect mid- and far-infrared radiation consists in bolometers, which are made up of arrays of small thermometers measuring the heat produced by absorption of radiation. They have many limitations, in particular being slow to respond and unable to detect weak levels of radiation.
Source: “Lighting the way to infrared detection”, Philippe Roelli, EPFL News