A luminous module with a scanning light beam, said module in particular being for a motor vehicle, and comprising: - a light source configured to generate a first light beam having a fast axis and a slow axis; - a wavelength-converting element comprising a conversion surface; - a focusing system arranged to produce the light beam, comprising - optical means comprising a collimating lens configured to produce a collimated beam from the first beam and configured to generate a second light beam from the first beam, and - scanning means that generate the light beam by reflection of the second light beam and that are arranged so that the light beam scans the conversion surface, the focusing system being configured so that the light beam is focused on the conversion surface, characterized in that the optical means comprise: - three non-planar cylindrical dioptric interfaces (21, 31, 41) placed after the collimating lens on a path of light rays from the light source, and comprising a first dioptric interface configured to produce a beam convergence only along the fast axis so that, along the fast axis, the dimension of the second light beam is tailored to the dimension of the scanning means, a second dioptric interface configured to produce a beam divergence only along the slow axis, and a third dioptric interface placed after the second dioptric interface on a path of the light rays from the light source, the third dioptric interface being configured to produce a beam convergence only along the slow axis, the second and third cylindrical dioptric interfaces (21, 41) being configured so that, along the slow axis, the dimension of the second beam is tailored to the dimension of the scanning means. - a light source configured to generate a first light beam having a fast axis and a slow axis; - a wavelength-converting element comprising a conversion surface; - a focusing system arranged to produce the light beam, comprising - optical means comprising a collimating lens configured to produce a collimated beam from the first beam and configured to generate a second light beam from the first beam, and - scanning means that generate the light beam by reflection of the second light beam and that are arranged so that the light beam scans the conversion surface, the focusing system being configured so that the light beam is focused on the conversion surface, - optical means comprising a collimating lens configured to produce a collimated beam from the first beam and configured to generate a second light beam from the first beam, and - scanning means that generate the light beam by reflection of the second light beam and that are arranged so that the light beam scans the conversion surface, the focusing system being configured so that the light beam is focused on the conversion surface, - three non-planar cylindrical dioptric interfaces (21, 31, 41) placed after the collimating lens on a path of light rays from the light source, and comprising a first dioptric interface configured to produce a beam convergence only along the fast axis so that, along the fast axis, the dimension of the second light beam is tailored to the dimension of the scanning means, a second dioptric interface configured to produce a beam divergence only along the slow axis, and a third dioptric interface placed after the second dioptric interface on a path of the light rays from the light source, the third dioptric interface being configured to produce a beam convergence only along the slow axis, the second and third cylindrical dioptric interfaces (21, 41) being configured so that, along the slow axis, the dimension of the second beam is tailored to the dimension of the scanning means.