Abstract: The refractive, transmissive or diffractive optical elements are made from a ceramic containing one or more oxides of the type X2O3, which is transmissive for visible light and/or for infrared radiation and which has a cubic crystal structure analogous to that of Y2O3. In preferred embodiments X is Y, Sc, In, or a lanthanide element, namely La to Lu, and in particular is Lu, Yb, Gd, or La. Also mixtures of oxides of the type X2O3 with oxides having different stoichiometries, such as HfO2 and/or ZrO2, may be present, as long as the cubic structure of the ceramic is maintained.

Abstract: The transparent polycrystalline optoceramic has single crystallites and at least 95 percent by weight of the single crystallites have a cubic pyrochlore or fluorite structure. The optoceramic is composed of an oxide of stoichiometry: A2+xByDzE7 wherein 0<x<1, 0<y<2, 0<z<1.6 and 3x+4y+5z=8; wherein A is at least one trivalent rare earth cation; B is at least one tetravalent cation; D is at least one pentavalent cation; and E comprises at least one divalent anion. Refractive, diffractive or transmissive optical elements are made with these optoceramics.

Abstract: The opto-ceramics and optical elements of the present invention are transmissive to visible light and/or to infrared radiation. They consist of a crystal combination in which individual crystallites have a cubic structure of the type Y2O3 and are made from In2O3 or a mixture of oxides of the type X2O3 in which X=Y, Lu, Sc, Yb, In, Gd, or La. Also mixtures of X2O3 with oxides having different stoichiometries, such as zirconium and hafnium oxide, are possible, as long as the cubic structure of the opto-ceramic is maintained. The optical elements prepared from the opto-ceramics are particularly suitable for mapping optics, such as objectives having reduced chromatic aberrations, in particular with approximately apochromatic mapping behavior. The optical elements of the present invention may be used in lens systems in combination with lenses of glass, but also with other ceramic lenses.

Abstract: The present invention relates to optoceramics and refractive, transmissive or diffractive optical elements manufactured thereof, their use and an optical imaging system. These optoceramics and optical elements are transparent to visible light and/or infrared radiation. The optoceramics consist of a crystal matrix, i.e. of polycrystalline material, wherein at least 95% by weight, preferably at least 98% by weight of the single crystallites have cubic pyrochlore or fluorite structure.

Abstract: The present invention addresses a mould for forming a ceramic green body useful for producing at least one optical lens consisting of optoceramics. The invention further refers to the use of such a mould. The (negative) form of the mould is close to the final geometry of the body to be formed (near net shape principle), at least regarding one functional area of at least one surface of the lens to be formed, which can be described by the following equation: y ? ? 1 = c ? ( ? x ? + b ) 2 1 + 1 - ( k + 1 ) ? c 2 ? ( ? x ? + b ) 2 + a 1 ? ( ? x ? + b ) 2 + a 2 ? ( ? x ? + b ) 4 + a 3 ? ( ? x ? + b ) 6 + a 4 ? ( ? x ? + b ) 8 + … ? , ( equation ? ? B ) wherein b is a constant and amounts to >zero and describes the deviation of the negative form of the mould from the form of the surface of the at least one lens.

Abstract: The present invention relates to a process for producing optical elements, in particular lenses made from an optoceramic, comprising a forming step, which step comprises the formation of a green body. The invention further relates to optical elements produced according to the before mentioned process. The process according to the present invention comprises a forming step including the application of a mould being close to the final geometry of the body to be formed (near net shape principle) including the application of moderate pressure between 0.1 MPa and 50 MPa, preferably between about 0.5 MPa and 25 MPa, in particular preferred between about 1 MPa und 12 MPa. The pressure is applied either on the ceramic powder mass during positioning of the ceramic powder mass into the form or is applied onto the ceramic powder mass within the form.

Abstract: The refractive, transmissive or diffractive optical elements are made from a ceramic containing one or more oxides of the type X2O3, which is transmissive for visible light and/or for infrared radiation and which has a cubic crystal structure analogous to that of Y2O3. In preferred embodiments X is Y, Sc, In, or a lanthanide element, namely La to Lu, and in particular is Lu, Yb, Gd, or La. Also mixtures of oxides of the type X2O3 with oxides having different stoichiometries, such as HfO2 and/or ZrO2, may be present, as long as the cubic structure of the ceramic is maintained.

Abstract: The opto-ceramics and optical elements of the present invention are transmissive to visible light and/or to infrared radiation. They consist of a crystal combination in which individual crystallites have a cubic structure of the type Y2O3 and are made from In2O3 or a mixture of oxides of the type X2O3 in which X=Y, Lu, Sc, Yb, In, Gd, or La. Also mixtures of X2O3 with oxides having different stoichiometries, such as zirconium and hafnium oxide, are possible, as long as the cubic structure of the opto-ceramic is maintained. The optical elements prepared from the opto-ceramics are particularly suitable for mapping optics, such as objectives having reduced chromatic aberrations, in particular with approximately apochromatic mapping behavior. The optical elements of the present invention may be used in lens systems in combination with lenses of glass, but also with other ceramic lenses.