The project focuses on significant metrology challenges that impede the advancement of high-performance optical and photonic systems. We develop, fabricate, and characterize innovative nano-structured optics with diffractive and sub-wavelength features for advanced imaging applications and surface metrology. The project also develops new interferometric methods for shape, or form, measurements of ultra-precise optical surfaces and wavefronts using advanced holograms.
Ultra-precise optics are essential to innovations in many high-tech areas, such as scientific imaging applications ranging from microscopy to astronomy, semiconductor manufacturing, medical imaging technology, defense, homeland security, consumer products, communication and information technology. Advanced optical elements incorporate features that yield vastly improved performance but pose significant new measurement challenges. Examples are complex surfaces that are neither flat nor spherical, diffractive optics with micro- and nano-scale surface structures, extreme accuracies, special materials and coatings, and adaptive technologies. The development and manufacture of these advanced features depend strongly on advances in traceable metrology for optical figure and wavefront. In many high-impact applications, the required form accuracies are at the (sub-) nanometer level. No general, widely-recognized, validated way exists to characterize complex and nano-structured optical surfaces, and the application range and uncertainty of existing methods are not well understood. The project addresses the metrology needs of U.S. Industry and Science for the manufacture and application of innovative optical elements and systems, and ultra-precise surfaces.