Ultra-fast nano-optics

Ultra-last nano-optics is a comparatively young and rapidly growing field of research aiming at probing, manipulating and controlling ultrafast optical excitations oil nanometer length scales. This ability to control light on nanometric length and femtosecond time scales Opens Lip exciting possibilities for probing dynamic processes in nanostructures in real time and space. This article gives a brief introduction into the emerging research field of ultrafast nano-optics and discusses recent progress made in it. A particular emphasis is laid oil the recent experimental work performed in the authors' laboratories. We specifically discuss how ultrafast nano-optical techniques can be used to probe and manipulate coherent optical excitations in individual I and dipole-coupled pairs Of quantum dots, probe the dynamics of surface plasmon polariton excitations in metallic nanostructures, generate novel nanometer-sized ultrafast light and electron sources and reveal the dipole interaction between excitons and surface plasmon polaritons in hybrid metal-semiconductor nanostructures. Our results indicate that Such hybrid nanostructures carry significant potential for realizing novel nano-optical devices such as ultrafast nano-optical switches as well as surface plasmon polariton amplifiers and lasers. [GRAPHICS] Two-dimensional finite difference time domain (FDTD) simulation of the spatio-temporal evolution of a 10 fs light pulse at a center wavelength of 810 nm propagating through a tapered, perfectly conducting metal-coated fiber probe of 100 nm aperture diameter. The field intensity vertical bar E-x(x,y,t)vertical bar(2) is displayed oil a logarithmic intensity scale at four different instants in time. After t similar to 14 fs the pulse center reaches the aperture, generating directly below it an ultra-short near-field spot of light. (C) 2009 by WILEY-VCH Verlag GmbH & Co. KGaA. Weinheim