STROBE Seminar: Prof. Demetri Psaltis and Prof. Christophe Moser, “From 3D to 2D and Back Again” and “Volumetric Printing in Scattering Resins”
Title: From 3D to 2D and back again
Presenter: Prof. Demetri Psaltis, Professor of Optics and the Director of the Optics Laboratory at the Ecole Polytechnique Federale de Lausanne (EPFL)
Abstract: The prospect of massive parallelism of optics enabling fast and low energy cost operations is attracting interest for novel photonic circuits where 3-dimensional (3D) implementations have a high potential for scalability. Since the technology for data input–output channels is 2-dimensional (2D), there is an unavoidable need to take 2D-nD transformations into account. Similarly, the 3D-2D and its reverse transformations are also tackled in a variety of fields such as optical tomography, additive manufacturing, and 3D optical memories. Here, we review how these 3D-2D transformations are tackled using iterative techniques and neural networks. This high-level comparison across different, yet related fields could yield a useful perspective for 3D optical design.
Bio: Demetri Psaltis is Professor of Optics and the Director of the Optics Laboratory at the Ecole Polytechnique Federale de Lausanne (EPFL). He was a Professor at the California Institute of Technology from 1980 to 2006. He moved to EPFL in 2007. His research interests are imaging, holography, biophotonics, machine learning, nonlinear optics, electrolysis for hydrogen production and optofluidics. Dr.Pslatis is a fellow of the IEEE, the Optical Society of America, the European Optical Society and the Society for Photo-optical Systems Engineering. He received the International Commission of Optics Prize, the Humboldt Award, the Leith Medal, the Gabor Prize and the Joseph Fraunhofer Award/Robert M. Burley Prize.
Title: Volumetric printing in scattering resins
Presenters: Prof. Christophe Moser, Director of the MicroEngineering Section at the Ecole Polytechnique Federale de Lausanne (EPFL)
Abstract: 3D printing has revolutionized the manufacturing of volumetric components and structures in many areas. Several fully volumetric light-based techniques have been recently developed thanks to the advent of photocurable resins, reaching print time of few tens of seconds while keeping sub 100 um resolution. We will review a variety of materials that have been reported by several groups including ours and that includes soft cell loaded hydrogels, acrylates, glass, ceramics that have been printed with volumetric printing. However, these new approaches only work with homogeneous and relatively transparent resins.
We will show a method that considers light scattering in the resin prior to computing projection patterns. Using a tomographic volumetric printer, we experimentally demonstrate that implementation of this correction is critical when printing objects whose size exceeds the scattering mean free path.
Bio: Christophe Moser started his career as an engineer at Hexagon Metrology in Switzerland after graduating from EPFL in physics in 1993. He obtained his doctorate degree in 2000 in optical information processing from the California Institute of Technology. Christophe co-founded and was the CEO of Ondax, Inc. (acquired by Coherent) in Monrovia, California. There, he has developed several commercially successful products based on volume holographic components such as tunable filters, wavelength stabilized high power diode lasers, pulse compressors and stretchers and Terahertz Raman spectroscopy systems.
In 2010, Christophe joined EPFL as an Associate Professor and is currently the Director of the MicroEngineering Section. His current research topics include light based volumetric additive manufacturing to reach micrometer resolution at the centimeter scale in different materials whose properties ranges from very soft – hydrogels to very hard – ceramics, glass. He is also interested in neuromorphic computing using linear and non-linear propagation in optical fibers as computing elements.