Kolloquien
Sommersemester 2017
URL zum ICS-Kalender dieses Seminars
Kirchhoff-Institut für Physik, Otto-Haxel-Hörsaal
freitags 17:15
Vorträge
21.7.2017 17:00
KIT, Campus Süd, Gaede-Hörsaal, Physik-Flachbau (Geb. 30.22)
Gemeinsames Kolloquium mit Karlsruhe, anschließend Empfang im Gastdozentenhaus „Heinrich Hertz“
Optical microcavities are a powerful tool to enhance light-matter interactions. Consisting of
microscopic reflective boundaries, they can concentrate, filter, and store light in wavelength-scale
volumes. This enables applications ranging from spectroscopy and sensing to quantum information.
To achieve large cavity enhancement on an accessible platform, we have developed
microscopic
Fabry-Perot cavities based on laser-
machined optical fibers.
We employ such cavities to realize efficient readout of individual quantum emitters
by means of
Purcell enhancement of fluorescence emission. We study
solid state quantum emitters such as color
centers in diamond, aiming at applications in quantum cryptography, all-optical quantum
computation, and efficient spin-photon interfaces.
In
a different direction in the context of microscopy, we use
microcavities for imaging and
spectroscopy applications. We have developed scanning cavity microscopy as a versatile method for
spatially and spectrally resolved maps of various optical properties of a sample with ultra-high
sensitivity. We demonstrate the
technique by quantitative imaging of the extinction cross-section of
gold nanoparticles and measurements of the birefringence and extinction contrast of gold nanorods.
Finally, we show that the Purcell effect can be used for cavity-enhanced Raman spectros
copy and
hyperspectral imaging. Simultaneous enhancement of absorptive, dispersive, and scattering signals
promises intriguing potential for optical studies of nanomaterials, molecules and biological
nanosystems.