What is Spectrometer Dark Current?

Sometimes thermal fluctuations have enough energy to generate electrons in the same way that photons do. These electrons are not part of the signal, but there is no way to distinguish them from the signal in the detector, so they become a source of noise. The dark current is the rate at which these thermal electrons are generated. The dark current is always present, even without light, which is why it is referred to as “dark.” Each pixel has a different amount of dark current, but it is usually stable over time, so it can be accounted for. If it is not stable, the pixel has to be treated as defective and interpolated over. Because dark current comes from thermal fluctuations, lowering the temperature of the electronics is a way to decrease the dark current.  StellarNet offers TE cooled detectors with 1-stage and 2-stage cooling options.