Have you ever considered how different our lives would be if we could travel by only making use of light instead of fuel? The goal of new research that is being carried out at Caltech is about how we can make a spacecraft traverse through our solar system while only using light for its power and acceleration.
The team has come up with a way of levitating and propelling objects by using only light. This has been achieved by incorporating specific nanoscale patterning to the surface of the objects. The scientists then have the ability to move and manipulate these small object by using ‘optical tweezers.’
The tweezers are capable of moving these objects by making use of the radiative pressure coming from a laser light beam that has been focused sharply. As of now, this amazing tool is only capable of moving tiny objects over a very limited distance. Ognjen Ilic who is a postdoctoral scholar and the first author of the study explains, ‘One can levitate a ping pong ball using a steady stream of air from a hairdryer. But it wouldn’t work if the ping pong ball were too big, or if it were too far away from the hair dryer, and so on.’
New research is being carried out to come up with means of moving objects varying in shapes and sized by only utilizing beams of light. The trick is to form precise patterns on the surface of the object. These specific patterns, nanoscale, interact with the light thus allowing to objects to adjust itself once it has been disturbed. This leads to the creation of a torque keeping it afloat by the light.
In essence, this implies that the object can maintain its stability and not depend on beams that are highly focused. The patterns can even enable the light source to be placed millions of miles away from the object.
Atwater, direct of the Joint Center for Artificial Photosynthesis, said, ‘We have come up with a method that could levitate macroscopic objects. There is an audaciously interesting application to use this technique as a means for propulsion of a new generation of spacecraft. We’re a long way from actually doing that, but we are in the process of testing out the principles.’
The research offers a conceptual theory stating that a spacecraft could be provided power in space from a laser light that is situated on Earth. The craft won’t have to carry any fuel thus enabling it to achieve higher speeds and make speeds to other stars as well.
The research has been published in the 18th March issue of the journal Nature Photonics.