‘Pseudogravity’ of Distorted Crystals Allows Light to Bend Like Black Holes

A new type of crystal was created with the ability to bend light like a black hole would, causing it to drift away from its usual straight path. The manipulation of the behavior of light was carried out using a phenomenon known as 'pseudogravity'.

What is Pseudogravity?

One of the observational tests of general relativity was the ability of light to bend its path in the presence of mass. This effect is crucial to various physical phenomena, such as black holes, gravitational lensing, and dark matter observations. However, since this effect is so tiny on human scales, it cannot be studied easily in the laboratory until the discovery of distorted photonic crystals.

Photonic crystals refer to materials with a periodic refractive index on nanometer scales. They occur naturally on objects such as opals and the wings of some butterfly species. These materials have been known since the 1800s, but it was not until the late 1980s that scientists could create simple photonic crystals.

In our modern times, scientists can make photonic crystal materials with particular properties, like customizing them to be sensitive to certain wavelengths of light. This breakthrough has allowed experts to focus on a type of material known as distorted photonic crystals.

Usually, no one wants a crystal to have any distortions. The more consistent a material is, the more uniform the behavior of light will be as it passes through. In the case of photonic crystals, the spacing of the crystal lattice was gradually deformed, shifting the periodic refractive index of the material. In the case of light, this means that the amount of refraction gradually varies, just as it does when it passes through a massive body like a black hole. As a result, light will follow the same kind of curved path as gravitationally lensed light.

Scientists call this phenomenon 'pseudogravity,' which can be used to simulate general relativity's effects. With advances in science, it is now possible to create photonic crystals that simulate the lensing effects of galaxies or even conduct a simulation of a black hole's event horizon.

Light Manipulation Technology

In Japan, a group of scientists from Tohoku University successfully manipulated the behavior of light as if it were under the influence of gravity. Led by Professor Kyoko Kitamura, the researchers carefully deformed a photonic crystal to invoke pseudogravity to bend a light beam.

The research started with the disruption of the crystalline lattice of the materials. Then, beams of light are shined through the distorted crystals while the scientists wait for them to deflect. According to Kitamura, their team devised a means to bend light within certain materials, much like the trajectory of objects bent by gravity.

The ability to manipulate light this way is a potential pathway for the next generations of communications technology. In the future, they are expected to send information in the terahertz range or even above 100 gigahertz. Researchers believe that these frequencies can be achieved through creative manipulation of light. The research findings also demonstrated that photonic crystals can harness gravitational effects, opening new opportunities for the field of graviton physics.