Overcoming Heisenberg's Uncertainty Principle In Polarization of Light Through The Direct Measurement Technique

Weak measurement: as light goes through a birefringent crystal the horizontally and vertically polarized components of light spread out in space, but an overlap between the two components remains when they emerge. In a “strong” measurement the two components would be fully separated.
Credit: Credit: Jonathan Leach

Researchers have developed a new technique that overcomes Heisenberg's Uncertainty Principle in measuring the polarization states of light.

The Uncertainty Principle was developed by a German theoretical physicist, Werner Karl Heisenberg. Known also as Heisenberg's Principle, the Uncertainty Principle states that the position and velocity cannot both be accurately known or measured at the same time. One may know the exact position but not the velocity and vice-versa.

This principle is one of the most famous underlying principle of quantum mechanics. In classical physics, it is easy to determine the exact momentum and position of a passing car at a specific time. But in quantum mechanics, where objects studied are at atomic and sub-atomic sizes, measuring both of these variables accurately at the same time becomes a problem.

This can be observed through the embedded video which shows MIT Professor Walter Lewin demonstrating the uncertainty principle with laser light. In it, he shows that as the position of the photons in the laser becomes more and more accurate, the direction of the laser light becomes wider and wider making it impossible to gauge its direction.

Recently, researchers believe they have a developed a technique that works around this bizarre behavior. This could lead to using light to encode information that can be read by quantum computers.