Laser source, comprising: ∘ a germanium-based semiconductor layer comprising a membrane suspended above a carrier layer, the suspended membrane being formed: • of a central portion, which is tensilely stressed in a plane parallel to the carrier layer, comprising an optical amplification section that is suitable for producing light radiation by stimulated emission, and • of a plurality of lateral portions forming tensioning arms that are opposite one another with respect to the central portion, and that are arranged so as to keep the central portion suspended and tensilely stressed, the tensioning arms having an average width larger than an average width of the central portion, the laser source furthermore comprises: ∘ an integrated waveguide that participates in forming an optical cavity with at least the optical amplification section, said integrated waveguide being located level with the carrier layer and at distance from the suspended membrane, and characterized in that it comprises: • a coupling section, which is located facing the optical amplification section, and which is suitable for allowing evanescent-wave optical coupling to the latter, and • at least one curved section that extends the coupling section, and which is arranged so that the integrated waveguide is placed at distance, in orthogonal projection, from the tensioning arms. ∘ a germanium-based semiconductor layer comprising a membrane suspended above a carrier layer, the suspended membrane being formed: • of a central portion, which is tensilely stressed in a plane parallel to the carrier layer, comprising an optical amplification section that is suitable for producing light radiation by stimulated emission, and • of a plurality of lateral portions forming tensioning arms that are opposite one another with respect to the central portion, and that are arranged so as to keep the central portion suspended and tensilely stressed, the tensioning arms having an average width larger than an average width of the central portion, • of a central portion, which is tensilely stressed in a plane parallel to the carrier layer, comprising an optical amplification section that is suitable for producing light radiation by stimulated emission, and • of a plurality of lateral portions forming tensioning arms that are opposite one another with respect to the central portion, and that are arranged so as to keep the central portion suspended and tensilely stressed, the tensioning arms having an average width larger than an average width of the central portion, ∘ an integrated waveguide that participates in forming an optical cavity with at least the optical amplification section, said integrated waveguide being located level with the carrier layer and at distance from the suspended membrane, and characterized in that it comprises: • a coupling section, which is located facing the optical amplification section, and which is suitable for allowing evanescent-wave optical coupling to the latter, and • at least one curved section that extends the coupling section, and which is arranged so that the integrated waveguide is placed at distance, in orthogonal projection, from the tensioning arms. • a coupling section, which is located facing the optical amplification section, and which is suitable for allowing evanescent-wave optical coupling to the latter, and • at least one curved section that extends the coupling section, and which is arranged so that the integrated waveguide is placed at distance, in orthogonal projection, from the tensioning arms.