Device for emitting a light beam, comprising: ∘ a vertical-cavity surface-emitting laser comprising a resonant cavity that extends along a main optical axis (Δ) and that is bounded by two mirrors (12, 13) a top mirror of which defines an emission surface; • the resonant cavity being adapted to support a plurality of transverse optical modes, including a fundamental transverse mode and transverse modes of higher order having a rotational symmetry of order two about the main optical axis (Δ); said device furthermore comprising: ∘ an index-contrast grating forming a diffusion lens, said grating being arranged on the emission surface and comprising a plurality of pads (22, 25 (i)) that are separate from one another and that are made of at least one material of a first refractive index (n H), said pads being encircled by a medium of a second refractive index (n L) different from the first index, said pads including: • a central pad, which is centered on the main optical axis (Δ), said device being characterized in that said grating furthermore comprises: • a plurality of peripheral pads (25 (i)), which are periodically arranged along one or more lines (24 (i)) that are concentric with respect to the central pad, and which are arranged so that the grating has, with respect to the main optical axis (Δ), a rotational symmetry of uneven order higher than or equal to three. ∘ a vertical-cavity surface-emitting laser comprising a resonant cavity that extends along a main optical axis (Δ) and that is bounded by two mirrors (12, 13) a top mirror of which defines an emission surface; • the resonant cavity being adapted to support a plurality of transverse optical modes, including a fundamental transverse mode and transverse modes of higher order having a rotational symmetry of order two about the main optical axis (Δ); • the resonant cavity being adapted to support a plurality of transverse optical modes, including a fundamental transverse mode and transverse modes of higher order having a rotational symmetry of order two about the main optical axis (Δ); ∘ an index-contrast grating forming a diffusion lens, said grating being arranged on the emission surface and comprising a plurality of pads (22, 25 (i)) that are separate from one another and that are made of at least one material of a first refractive index (n H), said pads being encircled by a medium of a second refractive index (n L) different from the first index, said pads including: • a central pad, which is centered on the main optical axis (Δ), said device being characterized in that said grating furthermore comprises: • a plurality of peripheral pads (25 (i)), which are periodically arranged along one or more lines (24 (i)) that are concentric with respect to the central pad, and which are arranged so that the grating has, with respect to the main optical axis (Δ), a rotational symmetry of uneven order higher than or equal to three. • a central pad, which is centered on the main optical axis (Δ), • a plurality of peripheral pads (25 (i)), which are periodically arranged along one or more lines (24 (i)) that are concentric with respect to the central pad, and which are arranged so that the grating has, with respect to the main optical axis (Δ), a rotational symmetry of uneven order higher than or equal to three.