Near-infrared is the region closest in wavelength to the radiation detectable by the human eye, mid- and far-infrared are progressively further from the visible spectrum. Other definitions follow different physical mechanisms (emission peaks, vs. bands, water absorption) and the newest follow technical reasons (the common silicon detectors are sensitive to about 1,050 nm, while InGaAs's sensitivity starts around 950 nm and ends between 1,700 and 2,600 nm, depending on the specific configuration). Unfortunately, international standards for these specifications are not currently available. COUNT 4
QSN1 What is the nearest wavelength to the radiation that a human eye can see? ANS1 Near-infrared QSN2 Along with the emission peaks and vs. bands mechanisms, what other physical mechanism is used to define near-infrared? ANS2 water absorption QSN3 In micrometers, when do common silicon detectors cease to be sensitive? ANS3 1,050 QSN4 What is the lowest level of sensitivity, in micrometers, for InGaAs? ANS4 950