A displacement transducer in integrated optics comprises a light source emitting a main monochromatic beam, a lens for collimating the main beam, a splitting plate for forming a measuring beam and a reference beam, a phase displacer for introducing a phase displacement of .pi./2 on part of the reference beam in order to form two reference beams, a first mirror integral with the moving object and a second mirror respectively serving for reflecting the measuring beam and the two reference beams on to the splitting plate, so as to form two interference signals, a splitting mirror for splitting these two interference signals and two detectors for respectively detecting these two interference signals. The transducer is formed in a SiO.sub.2 /Si.sub.3 N.sub.4 /SiO.sub.2 optical guide, the lens, plate and phase displacer being formed by local etching of the surface layer of the guide, the second mirror and the splitting mirror being formed by total etching of the guide.