Abstract: A device for forming an interference grating on a sample. The device including a laser emitting a light beam of wavelength ?, a beam splitter plate splitting the light beam into first and second beams, the first beam being deflected in a first direction, a first stationary deflection mirror for deflecting the first beam onto a point P of the sample at a first constant angle of incidence ?1, and at least one second stationary deflection mirror for deflecting the second beam along a final path that reaches point P of the sample at a second angle of incidence ?2 in order to form an interference grating on the sample at a pitch that depends on the angular difference ?. The device includes a movable deflection mirror to deflect the second beam from a plurality of first deflection points towards a plurality of second deflection points on the second mirror.

Abstract: The invention relates to a device for forming an interference grating on a sample, the device comprising a laser emitting a light beam of wavelength ?, a beam splitter plate splitting the beam emitted by the laser into first and second beams (11, 14), the first beam (11) being deflected in a first direction, a first stationary deflection mirror for deflecting the first beam onto a point P of the sample at a first constant angle of incidence ?1, and at least one second stationary deflection mirror for deflecting the second beam along a final path (17) that reaches said point P of the sample at a second angle of incidence ?2 in order to form an interference grating on the sample at a pitch that depends on the angular difference ? between the first and second angles of incidence ?1 and ?2, the path of the second beam being characterized in that it includes a movable deflection mirror (7, 7?) to direct and deflect the second beam from a plurality of first points of impact (71) from which the second beam (15) is d