LIGHT can now be used to track movements to within a fraction of an atom’s
width—and it’s all done with mirrors. The precision of the new measurement
technique might lead to the manufacture of faster microchips and even tinier
micro-machines.
For more than a century, scientists have used light to measure tiny
movements, with a method known as interferometry. But the new trick could
improve the precision of this old technique up to 500-fold, report Yuri
Ovchinnikov and Tilman Pfau of the University of Stuttgart.
The simplest type of interferometer splits a single light beam in two and
bounces…
