Selected applications of gratings in 3D visualization and optical processing

Abstract:
Lines etched on glass, or carved in air,
Gratings of wonder, beyond compare.
With precision and care, crafted e’er so fine,
To split, to reflect, or inter-twine.
Wordsworth, Keats, Tagore? No, chatGPT! This is the second stanza of a poem I asked chatGPT to write (with minor mods) on optical gratings, but it truly summarizes their beauty and what they do. The vivid colors from butterflies, the colors from a film of oil on water, or even the colors from a CD/DVD disc are all examples of structural spectra. In this talk, I will summarize different kinds of gratings, viz., transmission and reflection, and introduce holograms as the recording of an interference pattern between an object and a reference. I will discuss the nature of the object, viz., amplitude and/or phase, and show how the recorded hologram can be reconstructed to yield the 3D information. As example, I will show the reconstruction of fingermarks whose holograms are recorded from CTF coated samples here at Penn State. I will also discuss other applications of gratings, viz., color reconstruction of 3D objects for display holography, edge enhancement using volume holograms and Fourier processing transmission holograms for 3D image processing, beam steering for LiDAR applications, etc.

Biography: Partha P. Banerjee is a Professor for the Department of Electro-Optics and Photonics (EOP), where he was Chair from 2012-2020, and Professor of Electrical and Computer Engineering (ECE) where he was Chair from 2000-2005. His research interests include digital and dynamic holography, photorefractives, optical and acoustic metamaterials, nonlinear optics and acoustics, computational electromagnetics, and optical trapping. Most recently, his work on fingerprint holography, jointly with Penn State, was funded by the Department of Homeland Security. He is Fellow of Optical Society of America (OSA), International Society of Photonics Engineers (SPIE) and the Institute of Physics (FInstP), and senior member of the Institute of Electrical and Electronic Engineers (IEEE). He received the NSF Young Investigator Award in 1987. In recognition of his work on holography, he received the International Holoknight Award in 2019. At UD, Dr. Banerjee has established the Holography and Metamaterials (HaM) lab where he leads a research group comprising a research scientist and 6 PhD students. He has chaired/co-chaired the Optica international meeting on Digital Holography and 3D Imaging in 2010, 2016, 2019, and 2021, co-edited feature issues on Digital Holography and 3D Imaging multiple years in Applied Optics and JOSA A/B. To date, Dr. Banerjee has published 6 textbooks, 150 referenced journal papers, and over 175 conference papers/ presentations, and holds 1 patent. He has supervised 28 PhD dissertations and 19 MS theses.