The disclosure relates to a method for separating a layer from a
composite structure, the structure comprising a composite stack formed from at least a support substrate, which is partially transparent at a determined
wavelength, the layer to be separated and a separation layer interposed between the support substrate and the layer to be separated, the method comprising
irradiation of the separation layer through the support substrate by means of incident light
ray at the determined
wavelength in order to induce weakening or separation by exfoliation of the separation layer, the light
ray being inclined so as to form an
angle of incidence Θ such that θ>θmin, where θmin=sin−1((n1 / n0)sin(tan−1(s / 2h))), n1 and n0, respectively, being the
refractive index of the support substrate and the
refractive index of the external medium in contact with the support substrate, from which the
ray comes, S being the width of the ray and h being the thickness of the support substrate.