Spectral and surface analysis of heated micro-column arrays fabricated by laser-assisted surface modification

Micro-column array (MCA) structures fabricated by laser ablation of tungsten, tantalum, molybdenum, titanium, alloy 321, and Hastelloy276(TM) foils have been tested as possible candidates for wide-spectrum optical calibration sources and characterized. The surface of one side of the foil was structured to obtain periodically distributed micro-cones and micro-cavities. The spectral characteristics from samples of selected materials were measured at temperatures in the range from 500 to 1360 degreesC achieved by resistive heating of the foil samples in vacuum. Such characteristics measured from the MCA-structured surfaces of all foils show a significant enhancement towards the ideal blackbody and blackbody simulator characteristics compared to the non-structured surfaces. Surface modification of the MCA-structured samples was investigated using optical microscopy, scanning electron microscopy, and X-ray photoemission spectroscopy. Results obtained from tantalum-based samples indicated that they may be suitable for applications in blackbody-like emission devices. (C) 2003 Elsevier B.V. All rights reserved.