Research

Our research is focussed on light-solid interactions. We are interested in optical excitations in semiconductor and metal nanostructures (1-5), and we use photoemission electron microscopy (PEEM) for the direct observation of photon and plasmon surface dynamics (6-8).

In the past decade we have designed and built a unique aberration-correction microscope (PEEM) (9-11) and equipped it with a femtosecond laser system, a delay stage and a pulse shaper. This system allows us to directly visualize light propagation at the scale of a few nanometers.

We have used this instrument to study a number of optical devices such as optical antennas (12), plasmonic routers (13), plasmonic optical filters (13), plasmonic positioners (14), photonic waveguides and, most recently, photonic crystals (5).

These devices and structures will open applications in the area of optical signal processing on nanometer scales. Other potential applications would be sensors, harmonics generators, electron emitters etc.

Currently our group works towards the active control of light. We hope to demonstrate optical control with nanostructures positioned in the microscope. To prepare and characterize sample structures we use Focused Ion Beams, SEM, TEM.

In most of our work we also use numerical calculations to compare experimental results with physical theory (5, 10, 12-14).

(1) Light propagation and interaction observed with electrons

RC Word, JPS Fitzgerald, R Könenkamp

Ultramicroscopy 160, 84-89 (2016)

(2)Direct coupling of photonic modes and surface plasmon polaritons observed in 2-photon PEEM

RC Word, JPS Fitzgerald, R Könenkamp

Optics Express 21 (25), 30507-30520 (2013)

(3) Photonic near-field imaging in multiphoton photoemission electron microscopy

JPS Fitzgerald, RC Word, SD Saliba, R Könenkamp

Physical Review B 87 (20), 205419 (2013)

(4) Electron emission in the near-field of surface plasmons

RC Word, JPS Fitzgerald, R Könenkamp