Tools of light: laser tweezers
When you think of a laser, what comes to mind? Perhaps it’s a tool to carefully zap away unwanted things, destroying everything from body hair to cancer cells. Or perhaps it’s something a little more sci-fi, involving tractor beams that can grab asteroids or spacecraft and tow them through space.
Lasers can also be some of the most delicate tools in a science laboratory, capable of holding tiny microorganisms without killing them. While we haven’t figured out how to move asteroids with light just yet, we have worked out how to use lasers to move and manipulate individual particles and cells without destroying them.
Laser physicist Arthur Ashkin worked it out, to be precise. His invention, called ‘optical tweezers’, won him the 2018 Nobel Prize for Physics, shared jointly with Gérard Mourou and Donna Strickland for their technique to make very short, intense laser pulses.
