A substrate is treated by means of at least one pulse of a luminous flux of determined wavelength. The substrate comprises an embedded layer that absorbs the luminous flux independently of the temperature. The embedded layer is interleaved between a first treatment layer and a second treatment layer. The first treatment layer has a coefficient of absorption of luminous flux that is low at ambient temperature and rises as the temperature rises. The luminous flux may be applied in several places of a surface of the first layer to heat regions of the embedded layer and generate a propagating thermal front in the first layer opposite the heated regions of the embedded layer, which generate constraints within the second layer.