NBS Special Publication 637, Optical Fiber Characterization [1], is a two-volume compilation of previously published NBS Technical Notes concerning the characterization of optical fibers used for telecommunications. The Technical Notes appeared in the late 1970s and early 1980s, which was the period of commercial infancy of optical telecommunications fiber. During that period, the commercially ...

Multi-keV X-ray microscopy has been particularly successful in bridging the resolution gap between optical and electron microscopy. However, resolutions below 20 nm are still considered challenging, as high throughput direct imaging methods are limited by the availability of suitable optical elements. In order to bridge this gap, we present a new type of Fresnel zone plate lenses aimed at the s...