Keynote Speakers
James C. Wyant
James C. Wyant
Dean, College of Optical Sciences
Professor of Optical Sciences
University of Arizona
James C. Wyant is Professor of Optical Sciences and Dean of the College of Optical Sciences at the University of Arizona. He is a member of the National Academy of Engineering, and a Fellow of the Optical Society of America (OSA), the International Optical Engineering Society (SPIE), and the Optical Society of India. Wyant was the 1986 president of SPIE and he was recently elected to the OSA presidential chain (Vice President – 2008, President-Elect – 2009, and President - 2010). Wyant is Editor-in-Chief of the OSA journal Applied Optics. Wyant was a co-founder of the WYKO Corporation, 4D Technology, and DMetrix and the president of WYKO from 1984 to 1997. He has received several awards including the OSA Joseph Fraunhofer Award, 1992; SPIE Gold Medal, 2003; and the SPIE Technology Achievement Award, 1988. He has been the major advisor of 31 graduated Ph.D. students and 25 MS students.
Title: Dynamic Interferometry
A major limitation of precision interferometry is the sensitivity to the environment. This talk discusses different techniques for reducing the effects of vibration and atmospheric turbulence on interferometric measurements enabling precision interferometric measurements in uncontrolled environments. The application of these techniques for the measurement of surface vibration, the testing of optical components, the phasing of segmented optical components, and the measurement of deformations of diffuse structures will be described.
Prof. Dr. Wolfgang Osten
Prof. Dr. Wolfgang Osten
Institutsleiter
Institut für Technische Optik
Universität Stuttgart
Title: Some answers to new challenges in optical metrology
Optical technology is said to be an enabling technology for the so called key technologies such as biotechnology, microelectronics and production technology. However, the visible trend in the implementing of new technologies and creating new products is the continuous reduction of feature sizes - a trend that is tangibly expressed by the term nanotechnology. Meanwhile the critical dimensions of structures written in silicon are becoming considerably smaller than the wavelength of the applied light source and the roadmap of SEMATECH shows that this trend is to be sustained for the next 15 years. Beyond the reduction of feature sizes, both the degree of integration and the functionality are drastically increasing. A representative example is the cell phone where in a minimum of space original telephone features are combined with complex multimedia functions. But all improvement has its price. In the same way as the feature sizes are decreasing, the theoretical and practical constraints of making them and ensuring their quality are increasing. Consequently, modern production and inspection technologies are confronted with a bundle of challenges. An important barrier for optical imaging and sensing is the diffraction limited lateral resolution. The observation of this physical limitation is of increasing importance, not only for microscopic techniques but also for the application of 3D-measurement techniques on wafer scale level. Consequently, the search for resolution enhanced technologies becomes more and more important. A further challenge is the reliable detection of imperfections and material faults within the production chain. This means in-line metrology/defectoscopy is a must for future production systems. Only the real-time feedback of the inspection results into the production process can contribute to a consistent quality assurance in processes with high cost risk. Moreover the reliable measurement of free form surfaces, both technical and optical, the assurance of the traceability and the certified assessment of the uncertainty of the measurement results are ongoing challenges. But there are a lot of new approaches and tools which help to solve increasing complex inspection and measurement problems. New brilliant light sources with adaptable properties, optoelectronic detectors with improved space-bandwidth product and spectral sensitivity, spatial light modulators with both, an ability for amplitude as well as phase control and last but not least the continuously growing computer power are a good basis to meet the challenges. The challenges of the practical requirements and the physical limitations are addressed here by new approaches for testing semiconductor structures with enhanced resolution, the measurement of aspheric lenses with increased flexibility and the inspection of micro components with improved traceability.
Prof. Christian Depeursinge
Prof. Christian Depeursinge
Professeur titulaire
Laboratoire d’Optique Appliquée
Ecole Polytechnique Federale de Lausanne
Title: Digital Holographic Microscopy: a new perspective in 3D imaging at the nanoscale
DHM belongs to the larger family of "Coherent Imaging (CI) techniques in microscopy" (CIM), which includes also Interferometric Microscopy (IM). By the recourse to reduced coherence lengths, the so-called "Optical Coherence Microscopy" OCM imaging technique has been proposed, which is traditionally based on the exploitation of the coherence in the time domain (coherence gating), whereas DHM exploits coherence in the space domain, by providing a simple mean to reconstruct from the hologram data the wavefront scattered by the specimen. It is demonstrated in this talk how the new concept of "Digital Optics" (DO) can be useful by opening the way to a new kind of microscopy performing well down to the nanoscale. The DO concept can be applied to Digital Holographic Microscopy (DHM) in order to provide aberration- and distortion-free amplitude and phase images: Ultimately, wavefronts corrected by DO techniques can be combined to provide the reconstructed scattering potential by diffraction tomography (synthetic aperture). The 3D arrangement of the dielectric properties of the specimen can be directly derived from these data. Many new applications of DHM can be found in biology where longitudinal accuracies of a few nanometers and resolutions of a few hundreds of nanometers are achievable, provided that optical signals diffracted by the object are or can be made sufficiently large, eventually by tagging. Living biological cells in culture, including their intracellular structures, have been observed with accuracies far beyond that of confocal microscopy. New developments permit now to exploit fully the measurement of absolute phase contrast, and to derive quantitatively physiological parameters with DHM such as cell refractive index and morphology. DHM offers real time observations of very small movements and deformations (nanometers), which are produced, in particular, by stimulation of excitable cells like neurons or occurring naturally in red blood cells in connection with their metabolic activities. Direct imaging of living cells and tissues by DHM is deemed to offer henceforth unique investigation means in biology and medicine.
