Extraordinary Optics from Structured Nanoparticles: Nano Seminar Series

Seminar | October 18 | 2-3 p.m. | 120 Latimer Hall

 Dr. Danqing Wang, Miller Instititute / Materials Science & Engineering

 Berkeley Nanosciences and Nanoengineering Institute

Miniaturized and rationally assembled nanostructures exhibit extraordinarily distinct physical and chemical properties beyond their individual units. This talk will focus on structured metal nanoparticle lattices that show unique diffractive coupling with lattice spacings engineered close to the wavelength of light.

Collectively coupled plasmonic nanoparticles induce sharp, intense lattice modes compared to the broad resonances of individual nanoparticles, and the electromagnetic fields are strongly enhanced and localized near the sub-wavelength vicinity of nanoparticles. By harnessing different materials systems and lattice designs, various light-matter interactions can be engineered including nanoscale lasing and exciton-plasmon energy transfers.

We achieved reconfigurable, mechanical control of nanolasing by modulating lattice spacings of Au nanoparticles patterned on an elastomeric substrate. Plasmonic superlattices—finite-arrays of nanoparticles grouped into microscale arrays—support multiple band-edge modes capable of multi-modal nanolasing at programmed emission wavelengths. Moreover, integrating Yb3+/Er3+-co-doped upconverting nanoparticles with plasmonic lattices enables continuous-wave upconverting lasing at room temperature with record-low thresholds and high photostability.

The structured plasmonic nanoparticles can serve a versatile, scalable platform for large-scale quantum optics, nontrivial topological photonics and modified chemical reactivities.
Danqing Wang is a Miller postdoctoral fellow hosted by MSE here at Berkeley. She did her PhD in Applied Physics at Northwestern, co-advised by Prof. Teri W. Odom and Prof. George C. Schatz. Danqing has published in Nature Nanotechnology, Nature Materials, Chemical Reviews and Nano Letters as first- and co-first authors. She has also received several fellowships and awards including Miller Research Fellowship, Chinese Government Award for Outstanding Self-Financed Students Abroad and MRS Graduate Student Award.