Manipulation of luminescence by Mie-resonances

Prof. Dr. Jörg Schilling, Martin-Luther -Universität Halle-Wittenberg
Beginn
14. Dezember 2020, 16:15 Uhr
Ende
14. Dezember 2020, 18:00 Uhr
Veranstaltungsart
Physikalisches Kolloquium
Ort
Referent/in
Prof. Dr. Jörg Schilling
Veranstalter
Veranstaltungssprache
Englisch
Barrierefreier Zugang
ja
Öffentlich
ja

Manipulation of luminescence by Mie-resonances

The scattering of electromagnetic waves on spherical dielectric particles was first theoretically described by Gustav Mie more than 100 years ago. He already noticed several resonances (dipole, quadrupole, octupole …), which occurred in the scattering spectrum with increasing Particle size/wavelength ratio – the Mie resonances. Today the concept of Mie resonances is generalised to wave scattering from all kinds of particle shapes and the ability to create micro- and nanoparticles in all kinds of sizes and forms allows to also study these experimentally in much more detail. After a short overview of the general properties of Mie resonances I will focus in this talk on the impact of Mie-resonances on emitters. In particular I will describe, how the spontaneous emission of  Ge-quantum dots (spectral range 1200 -1600nm), which are embedded in silicon disc /cylinders with a controlled height and diameter, are influenced by the Mie-resonances. In general an enhancement of luminescence at the Mie-resonances is observed. Time resolved luminescence measurements demonstrate, that this is at least partly caused by the Purcell effect, which accelerates the radiative transitions at the resonances. To increase the Purcell factor, collective Mie-resonances of trimers and periodic chains of dielectric discs are investigated leading to higher Q-factor resonances due to a partial cancellation of radiative losses in the far field. A systematic investigation of the spectral luminescence response from resonator chains with increasing number of individual resonators additionally indicates the importance of a smooth field envelope to reach Q-factors of several hundreds. Finally, I will relate these results to photonic crystal nanobeams and give an outlook to further concepts, how Mie resonances can be used to manipulate luminescence.

Der Vortrag wird zusätzlich online übertragen. Der Livestream des MMZ kann öffentlich und frei zugänglich unter folgender Adresse angeschaut werden:
http://online.mmz.uni-jena.de/

 

 

 

Diese Seite teilen
Die Uni Jena in den sozialen Medien:
Ausgezeichnet studieren:
  • Logo der Initiative "Total E-Quality"
  • Logo des Best Practice-Club "Familie in der Hochschule"
  • Logo des Projekts "Partnerhochschule des Spitzensports"
  • Qualitätssiegel der Stiftung Akkreditierungsrat - System akkreditiert
Zurück zum Seitenanfang