A process for generating a carrier in an interferogram in interferometry device either of the “real-time holographic interferometry” type or of the “double-exposure holographic interferometry” type, including recording a first wave front on a hologram, the first wave front coming from an object; generating a second wave front, in which two wave fronts are superimposed orthogonally polarizing said first and second wave fronts, either naturally or by a modification stage; and passing the orthogonally polarized two wave fronts through a birefringent crystal, a polarizer and a detector to make the two wave fronts interfere.