Nano-optics, Nano-physics and Plasmonics

Teachers : Gerard Colas des Francs / Alexandre Bouhelier / Benoit Cluzel

1. Nano-optics 
Nano-optics is the study of optical phenomena near or beyond the diffraction limit.
The objective of this course is to present principles and applications of nano-optics.
We will first discuss light propagation in micronic and submicronic optical waveguides and give a short overview of integrated photonic devices. Next, we will consider micro-optical cavities as a key concept for efficient light-matter interaction with applications such as controlled spontaneous emission, low threshold laser or sensitive biosensors.

A second part will be devoted to optical nanosources.
We will briefly present single molecule spectroscopies methods with particular attention devoted to single photon source behavior.

We will give some simple but key concepts for modelling nano-optical systems.

2. Nanophysics and plasmonics
The objective of this course is to present electron confinements effects on the optical properties of matter, mainly semi-conductor and metal materials. After a short review of the optical properties of bulk materials, we will describe optical properties of their nanostructured counterparts.

In a first part, we will consider semi-conductor nanocrystal (quantum dots) for which electron confinement below its mean free path (~10 nm) leads to quantum confinement effects at the origine of size-dependent optical spectra.
Full engineering of quantum dots is therefore possible to achieve bright nanosources at any wavelength for various applications (biolabelling, quantum cryptography, …)

The second part of this course will concern plasmonics, or so-called optics of metal.
It relies on the specific modes (surface plasmon polaritons) sustained by metallic nanoparticles (~dozens of nm) to  control the light at a strongly subwavelength scale. Surface plasmon polaritons results from the coupling of a collective oscillation of the free electrons at the metal surface with an electromagnetic wave.
An important particularity of these modes is that their confinement can be down to the nanoscale (that is deeply sub wavelength) although at the price of losses. In this part, we will introduce the concept of delocalized and localized plasmons as well as current (surface enhanced spectroscopies, biosensing) or expected (integrated photonics devices, optical nanoantennas,…) applications.

Practical works: Surface plasmon waves, Optical tweezers, Whispering gallery mode resonators