AlbaNova Colloquium

Multiphoton Processes: Transforming an Imaginative Concept to High-Impact Technologies, from Materials Processing to Biomedicine

by Prof. Paras Prasad (Institute for Lasers, Photonics and Biophotonics, State University of New York at Buffalo)


The field of multiphoton processes, from purely theoretical and imaginative concept of two-photon absorption conceived by Maria Goeppert Mayer -long considered too weak to be of any practical significance, has transformed to practical applications in Multiphoton Technology. This multidisciplinary field capturing imagination and attention of scientists and engineers worldwide has transformed the science and technologies for Micro/ nanofabrication, optoelectronics, nanophotonics and biophotonics. In this talk the theoretical development and multiscale modeling that made vital contributions to fundamental understanding of multiphoton nonlinear optical properties of molecules and polymeric assemblies at the very onset of the newly emerging field of organic nonlinear optics will be introduced. This has provided clear pathways used in our laboratory to design and produce organic and polymeric materials with large two-photon absorption cross-sections ,even achieving population inversion leading to multiphoton lasing. Later developments include the role of rich density of low-lying intermediate states in twisted geometry chromophores, a radically new concept of metal cluster-mediated microscopic cascading, and co-operative enhancement in multibranched organic systems to dramatically amplify multiphoton processes.

Photoactive materials with large two-photon absorption have enabled us to demonstrate practical applications such as 3D microfabrication and high-density data storage, and to introduce and implement the concept of two-photon photodynamic cancer therapy to treat thick tumors. Multiphoton nonlinear microscopy is playing a vital role in high resolution and 3-D imaging of biological structures and in advancing the emerging field of Neurophotonics .

Some new directions in chiral contribution to multiphoton processes in a chiral polymeric medium in which electric and magnetic moments are naturally coupled, and multiphoton processes in an epsilon-near-zero medium will also be presented. The talk will conclude with a perspective on future challenges and opportunities in this burgeoning scientific field.

P.N. Prasad & D.J. Williams “Introduction to Nonlinear Optical Effects in Molecules and Polymers, John Wiley & Sons, New York (1991)

P.N. Prasad “Introduction to Biophotonics”, John Wiley & Sons, New York (2003)

P.N. Prasad “Nanophotonics”, John Wiley & Sons, New York (2004)

P.N. Prasad “Introduction to Nanomedicine and Nanobioengineering”, John Wiley & Sons, New York (2012)


About the speaker:

Prof. Prasad currently holds the unique multidisciplinary position of SUNY Distinguished Professor of Chemistry, Physics, Electrical Engineering, and Medicine (four departments spanning three schools). He is the Samuel P. Capen Chair of Chemistry and the Executive Director of the multidisciplinary Institute for Lasers, Photonics and Biophotonics, which he founded in 1999. His pioneering contributions in interdisciplinary research at the interface of photonics, nanotechnology, and biomedicine have broadly impacted healthcare, energy, and optical technologies. Scientific American named him among the world’s top 50 science and technology leaders. He has authored over 900 scientific papers; four field-defining monographs, widely used in teaching worldwide, in nonlinear optics, biophotonics, nanophotonics, and nanomedicine; eight edited books; and numerous patents. He introduced and advanced new frontiers of organic nonlinear optics, multiphoton physics, nanophotonics, biophotonics and nanomedicine. His Google Scholar h-Index is 137, with ~82,000 citations. His many awards for research excellence include 2021 IEEE Photonics Society William Streifer Scientific Achievement Award; IEEE Pioneer Award in Nanotechnology; the American Chemical Society Peter Debye Award, Morley Medal and the Schoellkopf Medal; SPIE’s highest honor of Gold medal; Optical Society Michael Feld Biophotonics award; Western New York Health Care Industries Technology/Discovery Award; SUNY Excellence in the Pursuit of Knowledge award; UB’s first Innovation Impact award; UB President’s Medal;, Guggenheim Fellowship; and Sloan Fellowship. He is an elected foreign fellow of the Brazilian Academy of Sciences, the National Academy of Sciences, India, and a fellow of the National Academy of Inventors. He is a fellow of APS, Optica (OSA), SPIE, and IEEE, and was listed among Thompson Reuters “Highly Cited Researchers” for 2014 & 2016. He has been awarded Honorary Doctorates from KTH in Sweden, Aix-Marseille University in France, MEPhI in Russia, Federal University of Pernambuco in Brazil and Indian Institute of Technology, Jodhpur. Globally, his technologies have produced nine 9 spin-off companies, including publicly-traded Nanobiotix, now in advanced clinical trials for cancer therapy.