PRACTICAL FABRICATION TECHNIQUES FOR DURABLE "MOTH EYE" OPTICAL ABSORBERS

IN THIS PROJECT THE RESEARCHERS WILL SYSTEMATICALLY EXAMINE "MOTH EYE" OR GEOMETRIC TRANSITION STRUCTURES FOR USE AS OPTICAL ABSORBING SURFACES TO REDUCE SCATTERED LIGHT INSIDE SENSITIVE OPTICAL INSTRUMENTS. THE EMPHASIS WILL BE PLACED ON FABRICATION TECHNIQUES THAT MEET ALL THREE OF THE FOLLOWING CRITERIA: (1) TO BE PRACTICAL FROM AN EVENTUAL MANUFACTURING STANDPOINT; (2) TO PROVIDE A RUGGED, DURABLE SURFACE STRUCTURE; AND (3) TO BE AMENABLE TO IN SITU FABRICATION ON THE INTERIOR SURFACES OF SUNSHIELDS, ETC. INPHASE I, A SPUTTER-ETCHING CATHODE ASSEMBLY WILL BE CONSTRUCTED AND USED TO FABRICATE SAMPLES WITH GEOMETRICALLY TRANSITIONED SURFACES IN THREE DIFFERENT CLASSES OF MATERIAL: A LOW INDEX DIELECTRIC, A SEMICONDUCTOR, AND A PURE METAL. THE RESULTING SURFACES WILL BE STUDIED BY SCANNING ELECTRON MICROSCOPY AND THEIR OPTICAL ABSORPTION CHARACTERISTICS WILL BE MEASURED EXPERIMENTALLY.