Fibre optic sensor for detecting an excitation in proximity to a fibre optic assembly, said excitation inducing a phase modulation of an optical signal propagating in said fibre optic assembly, said sensor comprising: - a laser assembly of at least one laser, said laser assembly being configured to emit at least one laser beam; - a fibre optic assembly having a first end (E 1) and a second end (E 2); - an optical system configured to: ∘ inject via said first or said second end, at least one portion of said laser beam; ∘ receive via said first end, at least one signal beam (Fs) originating from the portion of the laser beam injected into and propagated in said fibre assembly; ∘ generate at least one reference beam (Fr) based on said laser beam or said signal beam; ∘ produce at least one interference zone corresponding to the interference between a portion of the reference beam and a portion of the signal beam; - a digital holography assembly comprising: ∘ a liquid-crystal spatial light modulator configured to receive a portion of the signal beam (Fs) and a portion of the reference beam (Fr); ∘ a camera configured to receive said interference zone generating an interference pattern, said interference pattern being addressed electrically to said liquid-crystal spatial light modulator in order to create a phase hologram there corresponding to it; - at least one optical detector configured to detect an output optical signal beam resulting from: ∘ the diffraction of said portion of the signal beam and/or said portion of the reference beam received by the hologram inscribed in said liquid-crystal spatial light modulator and ∘ the transmission of said portion of the reference beam and/or said portion of the signal beam transmitted by said liquid-crystal spatial light modulator; - a processing unit (UN PD), at the output of said optical detector for processing said output optical signal beam (F out) for extracting information relative to said excitation. - a laser assembly of at least one laser, said laser assembly being configured to emit at least one laser beam; - a fibre optic assembly having a first end (E 1) and a second end (E 2); - an optical system configured to: ∘ inject via said first or said second end, at least one portion of said laser beam; ∘ receive via said first end, at least one signal beam (Fs) originating from the portion of the laser beam injected into and propagated in said fibre assembly; ∘ generate at least one reference beam (Fr) based on said laser beam or said signal beam; ∘ produce at least one interference zone corresponding to the interference between a portion of the reference beam and a portion of the signal beam; ∘ inject via said first or said second end, at least one portion of said laser beam; ∘ receive via said first end, at least one signal beam (Fs) originating from the portion of the laser beam injected into and propagated in said fibre assembly; ∘ generate at least one reference beam (Fr) based on said laser beam or said signal beam; ∘ produce at least one interference zone corresponding to the interference between a portion of the reference beam and a portion of the signal beam; - a digital holography assembly comprising: ∘ a liquid-crystal spatial light modulator configured to receive a portion of the signal beam (Fs) and a portion of the reference beam (Fr); ∘ a camera configured to receive said interference zone generating an interference pattern, said interference pattern being addressed electrically to said liquid-crystal spatial light modulator in order to create a phase hologram there corresponding to it; ∘ a liquid-crystal spatial light modulator configured to receive a portion of the signal beam (Fs) and a portion of the reference beam (Fr); ∘ a camera configured to receive said interference zone generating an interference pattern, said interference pattern being addressed electrically to said liquid-crystal spatial light modulator in order to create a phase hologram there corresponding to it; - at least one optical detector configured to detect an output optical signal beam resulting from: ∘ the diffraction of said portion of the signal beam and/or said portion of the reference beam received by the hologram inscribed in said liquid-crystal spatial light modulator and ∘ the transmission of said portion of the reference beam and/or said portion of the signal beam transmitted by said liquid-crystal spatial light modulator; ∘ the diffraction of said portion of the signal beam and/or said portion of the reference beam received by the hologram inscribed in said liquid-crystal spatial light modulator and ∘ the transmission of said portion of the reference beam and/or said portion of the signal beam transmitted by said liquid-crystal spatial light modulator; - a processing unit (UN PD), at the output of said optical detector for processing said output optical signal beam (F out) for extracting information relative to said excitation.