Laser marking method, laser marking apparatus and optical element

Abstract

In a method for producing a permanent mark in an optical element which consists essentially of a material that is transparent in the visible spectral region, a marking region of the optical element is irradiated with laser radiation in order to generate local, near-surface material changes in such a way that a mark of prescribed shape and size is generated. The laser radiation has an operating wavelength λ from the wavelength region between 1.1 μm and 9.2 μm. A thulium-doped fiber laser is preferably used as laser radiation source. The operating wavelength is selected in dependence from the material of the optical element such that the material exhibits a partial absorption with a transmittance between 60% and 98%. The method can be used, in particular, to provide spectacle lenses, contact lenses or intraocular lenses with marks.

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