Abstract: An opto-electronic instrument for remote temperature measurement having a measuring probe and a remote supply processing unit connected together by at least one optical fibre. The measuring probe includes at least one polarizer and a temperature sensitive element for receiving, modifying and retransmitting a luminous signal through the fibre which signal has been received from the luminous signal generator of the remote supply processing unit, which unit also includes a variable frequency filter controlled by a ramp generator for transforming the retransmitted luminous signal into a luminous signal, the intensity of which varies sinusoidally with time, and an opto-electrical transducer able to convert this latter luminous signal into a corresponding electrical signal of sinusoidal oscillation for which signal the period of oscillation is then calculated.