This device for determining wind speed comprises at least two laser sources emitting beams in different directions that are coplanar and such that each emission direction corresponds to a perpendicular emission direction. Each laser source is associated with focusing optics for focusing the emitted beam, a laser diode for receiving a reflected beam obtained after reflection by a particle present in the air of the corresponding emitted beam, a photodiode for transmitting an interference signal occurring between the emitted beam and the reflected beam, a processor for processing the obtained interference signals, and an optical cavity into which the reflected beam is reinjected in order to obtain an interference with the emitted beam.