Micro-radiographs stored in lithium fluoride films observed by scanning near-field optical microscopy

A new simple method to get soft X-ray micro-radiographs of biological material with a spatial resolution reaching 50 nm is described. A thin film of lithium fluoride (LiF) works as image detector, storing the micro-radiograph obtained exposing biological material to Extreme Ultra-Violet and soft X-ray radiations. Scanning near-field optical microscope (SNOM) is used to read the micro-radiograph at nanometric resolution up to L/12, collecting the fluorescence (L = 650 nm) excited by an Ar+ laser light (L = 458 nm)