| abstract |
The present invention relates to refractive, transmittive or diffractive optical elements, comprising a ceramic which is transmittive for visible light and/or for infrared radiation and has a cubic crystal structure (here, this means in the following a cubic structure which is analogous to that of Y 2 O 3 ), comprising an oxide of the type X 2 O 3 . According to preferred embodiments, X is selected from the group consisting of one or more of the elements Y, Sc, In, and/or elements of the lanthanides series La to Lu, in particular Lu, Yb, Gd or La. Also mixtures of X 2 O 3 with oxides having a different stoichiometry, such as for example HfO 2 and/or ZrO 2 are possible, as long as the cubic structure of the ceramic will be maintained. |