Abstract: An inhomogeneous optical layer is formed on a surface of a substrate in a vacuum coater, in which the substrate is moved along a travelling path having path sections and a substance is evaporated from its source and deposited on the surface while the deposited substance is exposed to gas which is able to react on the substance. In such an operation, the deposition rate of the substance is varied monotonously along the path in each of the path section in order that, in a layer formed by the deposition on the substrate, the content of the substance and that of the reaction product are varied monotonously in the direction of thickness. If the refractive index of the substance is different from that of the reaction product, the resultant refractive index in the layer is varied monotonously in the direction of the thickness of the layer.

Abstract: An inhomogeneous optical layer is formed on a surface of a substrate in a vacuum coater, in which the substrate is moved along a travelling path having path sections and two substances are evaporated from their respective sources and both of the substances are deposited on a common surface section of the surface. In such an operation, the deposition rate of each of the substances is varied monotoneously along the path in each of the path section in order that, in a layer formed by the deposition on the substrate, the content of each of the substances is varied monotonously in the direction of thickness. If the refractive index of one of the substances is different from that of the other of the substances, the resultant refractive index in the layer is varied monotoneously in the direction of the thickness of the layer.

Abstract: An inhomogeneous optical layer is formed on a surface of a substrate in a vacuum coater, in which the substrate is moved along a travelling path having path sections and a substance is evaporated from its source and deposited on the surface while the deposited substance is exposed to gas which is able to react on the substance. In such an operation, the deposition rate of the substance is varied monotonously along the path in each of the path section in order that, in a layer formed by the deposition on the substrate, the content of the substance and that of the reaction product are varied monotonously in the direction of thickness. If the refractive index of the substance is different from that of the reaction product, the resultant refractive index in the layer is varied monotonously in the direction of the thickness of the layer.

Abstract: An inhomogeneous optical layer is formed on a surface of a substrate in a vacuum coater, in which the substrate is moved along a travelling path having path sections and two substances are evaporated from their respective sources and both of the substances are deposited on a common surface section of the surface. In such an operation, the deposition rate of each of the substances is varied monotonously along the path in each of the path section in order that, in a layer formed by the deposition on the substrate, the content of each of the substances is varied monotonously in the direction of thickness. If the refractive index of one of the substances is different from that of the other of the substances, the resultant refractive index in the layer is varied monotonously in the direction of the thickness of the layer.