A system and a method for measuring distances, displacements and mechanical actions.

According to the present invention there is provided an optical transducer adapted to detect external mechanical actions acting on said transducer, said transducer comprising at least one sensing optical path (5) adapted to transmit at least one sensing optical signal (b') and to emit at least one sensing output electrical signal (d) along with at least one reference path (4) adapted to emit at least one output electrical reference signal (e). Moreover, at least one portion (5') of said at least one optical path (5) is adapted to be exposed to external mechanical actions, so that the transmission of said sensing optical signal (b') through said sensing optical path can be modified as a result of said mechanical actions, so that a phase shift between said sensing electrical signal (d) and said reference electrical signal (e) is generated.; Furthermore, said at least one reference path (4) comprises phase shifting means (11) adapted to maintain the phase shift between said at least one output sensing electrical signal (d) and said at least one output reference electrical signal (e) at a constant value in absence of any mechanical action exerted on said at least one sensing optical path (5), resulting in the working point of the transducer being kept within a range centered o a predefined phase shift, thus allowing to improve the sensitivity pf the transducer.