Abstract: A process for deep micro-engraving of a material includes the steps of superpositioning a plurality of elementary layers of respectively alternating indices on the material. Each of the layers is individually transparent to a predetermined wavelength in vacuum, and has an optical thickness equal to one quarter of the predetermined wavelength. The process further includes forming a plurality of openings in the elementary layers; the openings correspond to regions to be engraved on the material, and uncover selected portions of the material. The material is then illuminated by a laser beam of sufficient power to engrave, by sublimation, the uncovered material portions. The laser has the predetermined wavelength, and the plurality of layers form a mirror for the laser beam, which have a relatively high threshold of damage from the laser, and absorb substantially no power from the laser beam.