[FPU2019] Nanowire photonics

The ability to tailor waveguide cavities and couple them with quantum emitters has developed a realm of nanophotonics encompassing, for example, highly efficient single photon generation or the control of giant photon nonlinearities. Opening new grounds by pushing the interaction of the waveguide cavity and
integrated emitters further into the deep subwavelength regime, however, has been complicated by nonradiative losses when decreasing cavity dimensions. In this regard, semiconductor nanowires have been established as a fundamental building block of nanophotonics in highly efficient light-emitting diodes or solar cells, as the active component of nanoscale lasers and terahertz detectors, or as a passive element in novel photochemical sensors.

The major aim of this thesis project is to investigate theoretically the electrodynamic properties of semiconducting nanowires. Special emphasis will be given to the fundamental aspects of a variety of light-matter interaction properties. Spontaneous emission (photoluminescence) will be studied in connection to Purcell effect, namely: the modification of the emission properties (lifetime, polarization, directionality, ...) induced by the local environment, which is to say by the nanowire as an optical cavity supporting a variety of leaky/guided modes, and also by the substrate surrounding the nanowires.

Recent related works by our group:
(1) Tuning Spontaneous Emission through Waveguide Cavity Effects in Semiconductor Nanowires (Nano Letters 2019).
(2) Directional Emission from Leaky and Guided Modes in  Nanowires Measured by Cathodoluminescence & Photoluminescence (ACS Photonics 2016, Nano Lett. 2015).
(4) Generalized Brewster effects in Si-nanocylinder metasurfaces (Opt. Express 2018). 
(5) Fano resonances in Si nanowires (ACS Photon. 2017).

Applicants must have a degree in Physics, Chemistry or Electrical Engineering. The candidate is expected to work closely and actively with other theoreticians in the team (both supervisors and students), and also to collaborate with leading edge theoretical and experimental groups all over the world.
Contact: José A. Sánchez Gil (j.sanchez@csic.es).