Calibration Source Based on Micro-Column Arrays

"We propose to realize a new type of light source based on three-dimensional (3D) arrays of micro-columns, for calibration of detectors in the near IR and visible range of the spectrum. We intend to fabricate this array by laser ablation of stainless steelsurfaces and test their emission characteristics as a function of temperature (up to 2500 Deg F) through joule heating by electrical current injection. Our preliminary studies show that a metal surface with a 3D array of micro-columns has a very lowreflection coefficient over a wide range of the electromagnetic spectrum due to multiple reflections of the incident radiation on the micro-tips. Such a surface is almost a perfect model of a black body, and is expected to display a constant emittancevalue for the entire spectral range of interest. Unlike conventional light sources used as black body emitters, such as globars, the proposed source will allow full coverage of the electromagnetic radiation spectrum from near IR to mid-visible (~0.5 ¿m) ata constant near unity emittance value for the entire spectral range. The fabrication process of the proposed light source is cost-effective and will not require employment of costly and bulky vacuum equipment. The novel light source will have the followingfeatures: the source is compact and easy scalable, can be fabricated in a single process, and the characteristics of the source are very close to a black body emitter."