Method for producing a continuous diffractive optical element, device for carrying out the production method and continuous diffractive optical element

A method for producing a diffractive optical element for beam shaping of a laser beam having a first wavelength of at least 100 nm, comprising the steps:

• providing a laser mirror, the laser mirror having a layered structure made of a substrate and a dielectric layer, the dielectric layer resting against the substrate, or the laser mirror having a layered structure made of a substrate, a dielectric layer and an absorption layer, the absorption layer being located between the substrate and the dielectric layer, wherein the dielectric layer comprises a layered structure with a plurality of layers of different refractive indices,
• generating a plurality of bulges of the dielectric layer by treating the laser mirror with a series of focused heating laser beams having a second wavelength, wherein the plurality of bulges are formed directly by the heating laser beams in situ without adding any additional material or removing any material from the laser mirror,
• the plurality of bulges having a height perpendicular to the dielectric layer, and at least one bulge having a height of at least half the first wavelength, wherein the layered structure of the dielectric layer is maintained for the bulges, and wherein the generated bulges are permanent bulges that remain in the dielectric layer after the heating laser beams are no longer applied.