New method for the batch production of micro-Fresnel zone plates

A new method has been developed for making micro-Fresnel zone plates used in the coded imaging of x rays and α particles produced from laser fusion target implosions. The method allows the fabrication of numerous plating molds from a single master mold, which is particularly useful in α-particle imaging since each target shot requires a new zone plate. A master mold was made in polyimide using reactive ion etching, and a number of silicone rubber replicas were made of the mold. Each replica was then used to produce a number of photoresist final molds into which gold was electroplated. This microfabrication technique has produced high quality 10-μm-thick zone plates having 100 zones and a 5-μm-wide outer zone