BEGIN:VCALENDAR VERSION:2.0 PRODID:Data::ICal 0.22 BEGIN:VEVENT DESCRIPTION:Wade Hsu\, Yale University\n\n
Optics and photonics toda y enjoy unprecedented freedom. The ability to synthesize arbitrary light f ields (through wavefront shaping) and the ability to design structures at the subwavelength scale (through nanofabrication) enable us to realize phe nomena that could only be imagined in the past. In this talk\, I will pres ent several experiments and related theory that demonstrate exciting new p henomena which were previously inaccessible. A) Conventional textbook wisd om is that waves cannot be perfectly confined within the continuum spectru m of an open systems. Exceptions called &ldquo\;bound states in the contin uum&rdquo\; were hypothesized by von Neumann and Wigner [1] but not realiz ed. I will describe the first realization of such unusual states [2] and t heir manifestation as polarization vortices protected by topologically con served &ldquo\;charges&rdquo\; [3]. B) Our ability to control radiation al so enables the realization of non-Hermitian phenomena with no counterpart in closed systems. I will show how non-Hermiticity generates unique topolo gies in photonic band structures and lead to enhanced light&ndash\;< /span>matter interactions [4\,5]. C) Strong disorder in naturally occurring light-scattering media allows us to study mesoscopi c physics in a new arena. I will describe the control of optical transport via wavefront shaping\, and how the long-range correlations between multi ply scattered photons enable us to simultaneously control orders of magnit udes more degrees of freedom than previously thought possible [6\,7].
\n\n \;
\n\n[1] C. W. Hsu*\, B. Zhen* et al.\, Nature Reviews Materials 1\, 16048 (2016).
\n \n[2] C. W. Hsu*\, B. Zhen* et al.\, Nature 499\ , 188 (2013).
\n\n[3] B. Zhen*\, C. W. Hsu* e t al.\, Phys. Rev. Lett. 113\, 257401 (2014).
\n\n[4] B. Zhen*\, C. W. Hsu* et al.\, Nature 525\, 354 (2015).
\n\n[5] H. Zhou et al.\,< /em> Science\, eaap9859 (2018).
\n\n[6] C. W. Hsu et al.\, Phys. Rev. Lett. 115\, 223901 (2015).
\n\n[7] C. W. Hsu et al.\, Nature Physics 13\, 497 (2017).
\n DTSTART:20180219T203000Z LOCATION:Physics Building\, Room 204 SUMMARY:New Frontiers of Electromagnetic Phenomena at the Nanoscale END:VEVENT END:VCALENDAR