MSE Seminar: Dr. Carlos Rios Ocampo, UMD
Wednesday, September 20, 2023
2118 Chemical and Nuclear Engineering Building
301 405 5240
Solid-solid phase transitions in chalcogenides: a paradigm for tunable photonics
Abstract: Phase-change materials (PCMs), such as the chalcogenides GeTe, Ge2Sb2Te5, AgInSbTe, Sb2Se3, GeSbSe, etc., and the metal-to-insulator PCMs like VO2, have emerged as promising platforms to control both nanoscale electronic and photonic devices thanks to their fast, dramatic, and reversible change in electrical and optical properties. The last decade has seen a significant progress in PCMs tailored to free and on-chip optics and photonics for applications in metasurfaces, tunable filters, phase/amplitude modulators, color pixels, thermal camouflage, photonic memories/computing, etc. In particular, nonvolatile PCMs have drawn most attention since they enable an unprecedented combination of properties and the largest observed refractive index (electric permittivity) contrast. This fast-growing field brings together the efforts of several fields to develop, integrated, and exploit new alloys with superior switching speeds, optical transparency, opto-electronic control, and large-scale electronic and photonic integration. In this talk, I will talk about the fundamental principles behind PCMs, the state-of-the-art, and the achievements and current efforts in this field of the UMD’s Photonic Materials & Devices group.
Bio: Carlos A. Ríos Ocampo is an Assistant Professor at the University of Maryland, College Park, where he has led the Photonic Materials & Devices groups since 2021. Before joining UMD, Carlos was a Postdoctoral Associate at MIT, received a DPhil (PhD) degree in 2017 from the University of Oxford (UK), an MSc degree in Optics and Photonics in 2013 from the KIT (Germany), and a BSc in Physics in 2010 from the University of Antioquia (Colombia). Carlos’s scientific interests focus on studying and developing new on-chip technologies driven by the synergy between nanomaterials and photonics.