Abstract: In general, in one aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, the mask feature having a surface comprising a depression, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure. In general, in another aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure.

Abstract: In general, in one aspect, the invention features an apparatus that includes a plurality of optical elements arranged to form an image of an object. The elements include a first element comprising one or more regions of a polarizing material, the regions being shaped as one or more visual features, a polarizer, and a mounting assembly including a first mount for the first element and a second mount for the polarizer. At least the first or second mount is rotatable with respect to an optical axis between a first orientation and a second orientation. In the first orientation, the visual features are visible in the image of the object and, in the second orientation, the visual features are not visible in the image of the object.

Abstract: Methods include providing an article including a substrate, a first layer supported by the substrate, and an interface between the substrate and the first layer. The substrate is substantially transparent to radiation at a wavelength ? and the first layer is formed from a photoresist. The methods include exposing the first layer to radiation by directing radiation at ? through the substrate to impinge on the interface so that the radiation experiences total internal reflection at the interface.

Abstract: In general, in one aspect, the invention features an apparatus that includes a plurality of optical elements arranged to form an image of an object. The elements include a first element comprising one or more regions of a polarizing material, the regions being shaped as one or more visual features, a polarizer, and a mounting assembly including a first mount for the first element and a second mount for the polarizer. At least the first or second mount is rotatable with respect to an optical axis between a first orientation and a second orientation. In the first orientation, the visual features are visible in the image of the object and, in the second orientation, the visual features are not visible in the image of the object.

Abstract: In general, in one aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, the mask feature having a surface comprising a depression, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure. In general, in another aspect, the invention features a method that includes forming layer of a mask material on a surface of a first layer, patterning the layer of the mask material to obtain a mask feature, inducing mass transport of the mask material of the mask feature to obtain a modified mask feature, and transferring a profile of the modified mask feature into the first layer to form a first structure.