Light has been a topic of study in physics for centuries, and it has been assumed that most of the properties of light are already well understood by physicists. However, physicists at Ireland’s Trinity College Dublin recently published a potentially groundbreaking discovery concerning the nature of light. While studying the different effects that occur when light is passed through crystals, the team came across what is potentially an unknown form or property of light.
The team was studying a property known as angular momentum, which is the rotation of a system along the same axis of its movement. Physicists at Trinity College Dublin in the 19th century were some of the first to discover that light has angular momentum and can become a hollow spiral when passing through crystals. To conceptualize angular momentum, imagine a rifle bullet in flight; while the bullet is traveling forwards, it is also spinning around the same axis as the direction in which it is moving. The same goes for a screw being driven downward into a screw hole; as the screw is moving downward, it is also rotating.
In previous experiments, the angular momentum of light was found to rotate at a constant velocity. In this experiment, however, the angular momentum of light was slower due to quantum effects of the light interacting with the crystal. This marks the first time that light has been observed with a different velocity of angular momentum. According to the researchers’ findings, this discovery changes our current understanding of how light behaves in space:
The new form of total angular momentum we have identified gives an alternative representation of the state space in terms of beams with nonuniform polarization, leading to a new understanding of the effects of optical angular momentum.
This discovery could revolutionize optical communications, potentially enabling much faster and more secure connections. There is already research being conducted to develop computers that are powered by light rather than electricity, which could allow for near-instant communication between computers connected by optical cables. As physicists keep pushing the boundaries on quantum computing and nanophotonics, breakthroughs like this one could soon make today's technology look like stone tablets when compared with the computers of the near future.