Koenenkamp lab, Physics Department

Portland State University

 

Research:

 

Our work addresses interactions of light in solids. We explore light propagation and scattering in basic experiments and we design new devices for energy conversion and other applications. 

For the applications we typically prepare semiconductor and metal nanostructures and then assemble these to obtain novel light emitters, solar cells, transistors and sensors.

For the more fundamental work we have designed and built a high-resolution photoemission electron microscope (PEEM). This instrument allows to directly visualize optical, photonic and plasmonic effects. As the imaging process in this microscope is based on electron optics, excellent spatial resolution can be obtained. So far our best resolution is 4.3 nm - reached in 2011.

Our PEEM is equipped with a multi-color femtosecond laser system which allows us to do ultrafast non-linear imaging. 

 

In the image below we are quite literally visualizing light with electrons.

 

 

            

 

 

Interference image of scattered light waves in a thin transparent film

and a plasmonic gold nanowire.