Abstract: The invention concerns a device for quantifying and locating a light signal modulated at a predetermined frequency. According to the invention, it comprises a digital control unit (100), a plurality of photodiodes (D1,D2,D3,D4) arranged along two parallel, adjacent receiver lines (L+,L?) of similar dimensional and electric characteristics extending from an amplifier device (300) connected to a demodulator (400) and forming a differential pair at the input of the amplifier device (300). The controls over the diodes (D1,D2,D3,D4) are such that they are successively connected to the two receiver lines (L+,L?).