Optical system for spatiotemporally shaping the wavefront of the electric field of a light beam (1, 1') to be projected into a target volume, where the propagation axis is axis z, to create 3D patterned illumination in the target volume, comprising: (i)- a light emitting coherent pulsed source, coupled to a beam shaper, configured to give one initial illumination pattern whose transversal surface in the target volume being superior to the diffraction limit of the optical system, (ii)- at least one intermediate optical element (4, 4'), which is a dispersive grating for performing temporal focusing of the light beam (1, 1'), located, on the propagation axis (z), where an image of the illumination pattern is formed, (iii)- and a second optical element (3, 3') which is a spatial light modulator for modulating the phase of the electric field of the input light beam, and for realizing spatiotemporal multiplexing to create 3D patterned illumination in the target volume by: - replicating the initial illumination pattern, so as to have several replicated illumination patterns ( P i) in the target volume (5, 5'), each of the replicated illumination patterns ( P i) having a size at least equal to the size of the initial illumination pattern, and - controlling the position of each replicated illumination pattern (Pi), given by the transversal coordinates X i, Y i and axial coordinate Z i in the target volume (5, 5'), the coordinates X i, Y i and Z i being chosen independently from each other, the optical system further comprising a lens situated between the intermediate optical element (4,4') and the second optical element (3,3'); the second optical element (3, 3') being situated on the propagation axis z after the at least one intermediate optical element (4, 4') on the trajectory of the light beam (1, 1') at the Fourier plane of said lens; the second optical element (3, 3') being addressed with a lens effect for obtaining the axial coordinate Z i of the replicated illumination pattern (P i), characterized in that the second optical element (3, 3') being further addressed with a phase function that reproduces a grating or prism effect for obtaining the transversal coordinates Xi, Yi of the replicated illumination pattern (Pi) in the target volume (5, 5'). (i)- a light emitting coherent pulsed source, coupled to a beam shaper, configured to give one initial illumination pattern whose transversal surface in the target volume being superior to the diffraction limit of the optical system, (ii)- at least one intermediate optical element (4, 4'), which is a dispersive grating for performing temporal focusing of the light beam (1, 1'), located, on the propagation axis (z), where an image of the illumination pattern is formed, (iii)- and a second optical element (3, 3') which is a spatial light modulator for modulating the phase of the electric field of the input light beam, and for realizing spatiotemporal multiplexing to create 3D patterned illumination in the target volume by: - replicating the initial illumination pattern, so as to have several replicated illumination patterns ( P i) in the target volume (5, 5'), each of the replicated illumination patterns ( P i) having a size at least equal to the size of the initial illumination pattern, and - controlling the position of each replicated illumination pattern (Pi), given by the transversal coordinates X i, Y i and axial coordinate Z i in the target volume (5, 5'), - replicating the initial illumination pattern, so as to have several replicated illumination patterns ( P i) in the target volume (5, 5'), each of the replicated illumination patterns ( P i) having a size at least equal to the size of the initial illumination pattern, and - controlling the position of each replicated illumination pattern (Pi), given by the transversal coordinates X i, Y i and axial coordinate Z i in the target volume (5, 5'), the coordinates X i, Y i and Z i being chosen independently from each other, the optical system further comprising a lens situated between the intermediate optical element (4,4') and the second optical element (3,3'); the second optical element (3, 3') being situated on the propagation axis z after the at least one intermediate optical element (4, 4') on the trajectory of the light beam (1, 1') at the Fourier plane of said lens; the second optical element (3, 3') being addressed with a lens effect for obtaining the axial coordinate Z i of the replicated illumination pattern (P i), characterized in that the second optical element (3, 3') being further addressed with a phase function that reproduces a grating or prism effect for obtaining the transversal coordinates Xi, Yi of the replicated illumination pattern (Pi) in the target volume (5, 5').