An optical chromatic dispersion compensation module consists of a portion of fiber (10) comprising a variable pitch Bragg grating and a mechanical structure (1) consisting of two flexible mountings (2, 2') and one fixed mounting (3). The portion of fiber (10) is attached to said mechanical structure (1) at three points: A first soft mount point (5) is connected to the fixed mounting (3) and two rigid mount points (4, 4') are connected to the flexible mountings (2, 2'). The module also consists of a mechanical actuator (20) designed to act on the mechanical structure (1) to compress a first portion of the Bragg grating and to stretch a second portion of the Bragg grating while keeping the central section of the grating fixed. The chromatic dispersion value produced by the Bragg grating filter is thus modified, while its central wavelength remains fixed.