Device for digitizing optical signal and device for measuring temperature and elongation

The invention relates to a device for digitizing a light signal, comprising: a light detector, which is designed to detect a light signal and to generate an electrical signal corresponding to the light signal; an envelope detector configured to determine an amplitude of an electrical signal generated by the light detector and to output an electrical signal corresponding to the amplitude; an analog-to-digital converter configured to digitize the electrical signal output by the envelope detector and to output corresponding data; the invention relates to a device for calibrating an envelope detector, comprising an envelope detector, a variable voltage source comprising an output which is connected or connectable to an input of the envelope detector, said device being designed to calibrate the envelope detector by means of the variable voltage source. The invention further relates to a method for digitizing an optical signal, to a device for spatially resolved measurement of temperature and elongation by means of