Controlling spontaneous emission with surface waves
Prof Jean-Jacques Greffet, Institut d‘Optique, Paris
Spontaneous emission can be dramatically modified by controlling the environment of the emitters. In this talk, we will deal with spontaneous emission of quantum dots embedded in a nanoantenna and with thermal radiation for the design of IR sources. In the first part of the talk, I will report the study of a patch nanoantenna. It consists of quantum dots deposited on a planar gold substrate and covered by a thin gold disk. Experimental results will be reported. It will be shown that the nanoantenna allows controlling the emission direction and the decay rate of a cluster of quantum dots. In the second part of the talk, I will discuss the possibility of taking advantage of recent advances in nanophotonics to design IR thermal sources. For fundamental reasons, spontaneous emission is rather inefficient in the IR so that incandescent sources are still used when cheap and compact IR sources are needed. Yet, these sources are quasi-isotropic, have a broad spectrum, cannot be modulated faster than a few tens of Hertz and are energetically inefficient. I will show that by taking advantage of recent advances in nanophotonics, it is possible to control the emission of IR radiation and design directional, quasimonochromatic sources. I will introduce new ideas that pave the way towards fast modulation of the emitted flux.
The Distinguished Lecturer Series (DLS) follows a colloquium format for a broad audience and will be followed by a reception to provide an opportunity for meeting the speaker.