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 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 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. <EOS>