In 1801, Thomas Young's revolutionary Double Slit Experiment changed physics forever by proving that light is both a particle or a wave, depending on how one changed the parameters of the experiment at hand. From that day onward, researchers have tried to image the particle/wave nature of light in real time, a notion considered all but impossible to do, until now.
A research team led by Fabrizio Carbone at EPFL has now carried out an experiment with a clever twist: using electrons to image light. The researchers have captured, for the first time ever, a single snapshot of light behaving simultaneously as both a wave and a stream of particles.
The laser adds energy to the charged particles in the nanowire, causing them to vibrate. Light travels along this tiny wire in two possible directions, like cars on a highway. When waves traveling in opposite directions meet each other they form a new wave that looks like it is standing in place. Here, this standing wave becomes the source of light for the experiment, radiating around the nanowire.
This is where the experiment's trick comes in: The scientists shot a stream of electrons close to the nanowire, using them to image the standing wave of light. As the electrons interacted with the confined light on the nanowire, they either sped up or slowed down. Using the ultrafast microscope to image the position where this change in speed occurred, Carbone's team could now visualize the standing wave, which acts as a fingerprint of the wave-nature of light
Seen above is the duality of light captured in living "color", something Thomas Young would have appreciated without question. :) Seen below is a cool video showing how the scientists did the deed.