The invention relates to a device (1, 1′, 1″) for cooling an optical fiber (13), including two portions (20, 29), each of the portions (20, 29) including at least one receiving surface (204, 294) on which a half-channel (240, 2490) is provided, such that, once the two portions (20, 29) are placed in contact at the receiving surface (204, 294) thereof, the two portions (20, 29) form a main through-channel for accommodating the passage of the optical fiber (13), characterized in that each of the portions (20, 29) is a block of a thermally conductive material and in that at least one (20) of the portions includes a cylindrical secondary channel (209), which is in fluid connection with a plurality of openings (2046) distributed along the half-channel (2040) of said portion (20), in order to form a heat-transfer fluid distribution chamber for the plurality of openings (2046).