Plenary Presentations

Plenary Session Presentations

Opening Plenary
Closing Plenary

Dr. Ty Olmstead

Ocean Insight

Biophotonics Success and Future: Where have we been and where do we go next

Since before the first studies of Endre Mester with the Ruby laser where he showed accelerated wound healing, biophotonics has demonstrated transformational solutions in Medicine. This talk will present a review of several successes biophotonics has had in Medicine and new opportunities. Devices including Laser Scribing, OCT, Refractive Lasers, and Femtosecond Laser-Assisted Cataract Surgery have transformed the standard of care in Medicine. As we look back and to the future, what is next for biophotonics in Medicine? Transformation of aphakic IOLs? COVID-19 detection? Drug fabrication? Regenerative Medicine? The potential of biophotonics continues to solve many challenging problems in Medicine. This talk will address these and other relevant topics to biophotonics.

Dr. Abdalla R Nassar

Applied Research Laboratory (ARL) at Penn State

Quality assurance in laser-based, metal additive manufacturing: Generation and detection of systematics and stochastic defects

Laser-based powder bed fusion (PBF) and directed energy deposition (DED) additive manufacturing have been embraced by much of the aerospace and defense industry for part production and repair. Unfortunately, there still remains considerable uncertainty regarding the causes and effects of many defects types observed in PBF and DED components. Numerous conditions can lead to the formation of defects (i.e. internal discontinuities or undesirable microstructure) that can negatively affect build and part quality. Some of these defects are easily attributable to systematic errors (e.g. poor processing parameters or contamination). However, many others appear stochastic in nature, appearing randomly even under ideal processing conditions. Here, we detail recent work seeking to elucidate the mechanisms by which systemic and stochastic defects form and approaches to detecting both types in- situ. We illustrate that naturally-occurring, stochastics flaws can be emulated via perturbation of processing conditions and can be sensed via illuminated melt pool imaging and observation of the vapor plume produced above the melt. Similar approaches can also be utilized to detect systematic variations in processing parameters. It is also possible to predict and use feed forward control to avoid many defect types. The presented analyses and methodologies present a path forward for mitigation and detection of both systematic and stochastic defects.

Prof. Kenichi L. Ishikawa

Research Institute for Photon Science and Laser Technology, The University of Tokyo

Building Science and Theory for Smart Laser Manufacturing

For a brighter future of the global society, Japan is committed to achieving sustainable growth and becoming a pioneer in the establishment of a new social model Society 5.0. Society 5.0 is defined as a human-centered society that balances economic advancement with the resolution of social problems by a system that highly integrates cyberspace and physical space, i.e., cyber-physical system (CPS). To promote smart production and eventually realize Society 5.0 and sustainable development goals, we develop CPS laser manufacturing capable of proposing the optimal processing parameters using artificial intelligence and numerical calculations based on the science and theory of laser processing combined with massive data of high quality.

Understanding laser processing belong to multiscale and multidisciplinary cutting-edge science. For example, how atoms, molecules, and materials behave under intense laser irradiation is at the forefront of atomic, molecular, optical, and condensed-matter physics, involving highly nonlinear, dynamical processes. One of our focuses is to understand and simulate such strong laser matter interaction by combining different techniques, even starting from the first principles of quantum mechanics.

We are developing various new methods to accurately calculate the laser-driven electron dynamics and energy transfer from laser to electrons. Also, combining first-principles and molecular dynamics calculations, we start to quantitatively reproduce how atoms are ejected from a laser-irradiated surface. In the macroscopic scale, for instance, we study multiphysics modeling of complex thermal multiphase flows with phase change. We build a nation-wide collaboration network of theoreticians as well as experimentalists that develop, e.g., cutting-edge operando measurement techniques such as high-speed photography and angle-resolved photoemission spectroscopy.

Dr. Jyoti Mazumder

University of Michigan in Ann Arbor

Past Present and Future of Metallic Additive Manufacturing

Economist Magazine hailed Additive manufacturing (AM) as “Third Industrial Revolution”. AM also features prominently in Factory 4.0. It has been practiced in one form or other for more than 5000 years. A pyramid in Egypt was built at 2800 BC using layer-by-layer construction. Modern versions for this technology are around for almost three decades. The first patent on steriolithography was issued in 1986 to Charles Hull. In many ways it is “back to the future”

Presently, there are several 3-D printing machine manufacturers using wide range of raw materials from wax to metals using various techniques. They are also making products from food to fashion. Even AM machine capable of remote manufacturing is now possible.

However one of the critical needs is “Certify as you build”. Due to relatively low volume production, conventional statistical quality control is difficult. In-situ diagnostics and quality assurance is needed and that is relatively unexplored field. In-situ optical diagnostics and its capability to integrate with the process control is a prudent alternative. New optical Sensors are being developed to control product health and geometry using imaging, cooling rate by monitoring temperature, microstructure and composition using optical spectra. Ultimately these sensors will enable one to “Certify as you Build”. Recently the author and his group have developed a technique to analyze the plasma spectra to predict the solid-state phase transformation, which opens up the new horizon for the materials processing and manufacturing.

Mathematical model developed for the process includes most of the physics but need substantial computing time. An effort needs to be made to develop surrogate models, which can converge within 10ms to enable the process control. Flexibility of the process is enormous and essentially it is an enabling technology to materialize many a design. Conceptually one can seat in Santa Fe and fabricate in Sheffield. This paper provides an overview of the past history, present status and future needs and potential.

Dr. Nina Lanza

Los Alamos National Laboratory

Using laser-based analysis techniques on Mars with the ChemCam and SuperCam instruments

The NASA Curiosity rover has been exploring the surface of Mars for the past eight years, carrying with it the ChemCam instrument as part of its scientific payload. ChemCam is a suite of instruments that includes a laser-induced breakdown spectroscopy (LIBS) instrument, which provides chemistry information about geologic materials at standoff distances of up to 7 m from the rover. The ChemCam LIBS instrument has produced over 800,000 individual spectra, an unprecedented number of observations from a single instrument on Mars. With these and other instrument data, we have learned that Curiosity’s landing site in Gale crater once hosted a long-lived freshwater lake that was habitable. As Curiosity continues to produce ever more data, a new NASA Mars rover was recently launched, with a landing date of February 18, 2021. Called Perseverance, this new rover has an all-new science instrument payload, including the SuperCam instrument suite. SuperCam uses a combined LIBS-Raman laser instrument to analyze geologic materials, which allows for direct measurement of both chemistry and mineralogy, thereby uniquely identifying geologic materials. SuperCam also includes a microphone that can record the sound of LIBS acoustic signals, which provides additional information about the material properties of martian rocks. In this talk, I will describe our two instruments, give an overview of current results from ChemCam and the Curiosity mission, and discuss the goals for the soon-to-land Perseverance mission.