The technology could open up new chapters in understanding brain activity and medical diagnosis in realtime.
Although Scientists have long suspected that light can create its own conical wakes like the one created by a sonic boom, the problem has always been, if this is so, how would you be able to capture it with a camera?
Although the answer – with a very fast camera, seems obvious doing so is a phenomenally difficult task.
Researchers at Washington University in St. Louis have finally managed to crack the problem with a “streak camera” that can measure both the temporal data and the image at a mind boggling 100 billion frames per second.
They have in fact recorded these photonic shockwaves using this equipment.
To visualise the cones, the team shot short (7 picoseconds) green laser pulses through a tunnel full of dry fog that was sandwiched between plates made out from silicone rubber and aluminum oxide.
Since the laser moved faster in the tunnel than in the plates, as a result it produced a sonic boom-like effect since some of the light was dragged behind.
Of noteworthy importance is the approach to the camera: while other techniques for capturing fleeting events typically require multiple exposures to see anything at all, the streak camera, on the other hand, required just one.
Furthermore, the streak camera allowed the capture of events which typically don’t repeat in the exact same way, such as the laser pulses.
This breakthrough, has lead to new insights into the properties of light which could have application in biology and medical science. It turns out that the streak camera is quick enough to capture neurons as they are being fired, which could help map brain activity in realtime.
This breakthrough could significantly help improve our understanding of how the brain works and could potentially help diagnose brain-related diseases.