Deep subwavelength imaging of light confined in ordered and disordered systems

Francesca Intonti

Mo, 21 Mar 2016, at 10:00. Aula Querzoli

pdf of the presentation

As materials functionality becomes more dependent on local physical and electronic properties, the importance of optically probing matter with true nanoscale spatial resolution has increased. In the study of materials, optical microscopy maps the spatial distribution of a specific quantity (such as morphology), whereas optical spectroscopy provides physical and chemical material properties (such as electronic structure). An ongoing challenge to understanding matter at the nanoscale is the difficulty in carrying out local optical spectroscopy.

For example, numerous optical technologies and quantum optical devices rely on the controlled coupling of a local emitter to its photonic environment that is governed by the local density of optical states (LDOS). Where the LDOS provides a direct measure for the probability of spontaneous light emission. The tremendous progress in designing and tailoring the LDOS of nano-resonators requires an investigation tool that is able to access the detailed features of the optical localized resonant modes with deep-subwavelength spatial resolution.

In this lesson, I will discuss subwavelength imaging of light localized in nano and micro optical resonators by means of scanning near-field optical microscopy (SNOM). I will start with the investigation of ordered systems, as photonic crystal nanocavities and microring resonators, and then I will show how the proposed technique can be applied also on systems where light confinement occurs via multiple scattering from disordered placed scatterers.

[1] J. D. Joannopoulos, P. R. Villeneuve, and S. Fan, Nature 386, 143 (1997)

[2] F. Intonti, S. Vignolini, F. Riboli, A. Vinattieri, D. S. Wiersma, M. Colocci, L. Balet, C. Monat, C. Zinoni, L. H. Li, R. Houdre, M. Francardi, A. Gerardino, A. Fiore, and M. Gurioli, Phys. Rev. B 78, 041401(R) (2008)