An attenuating device for attenuating optical power of a light beam, comprises
an at least partly absorbing element adapted to receive and attenuate the optical
power of the light beam, and a supporting element for supporting on at least one
side the at least partly absorbing element. The at least partly absorbing element
comprises at least one layer coated or evaporated on the supporting element with
an increasing, decreasing, or varying thickness. The supporting element is provided
with a material having a crystalline structure to provide compensation to a local
heating in the at least partly absorbing element resulting from absorption of the
light beam.