This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Stanford engineers and colleagues designed a chip that can take a muddled mixture of light from multiple lasers and output clean beams of light. It's the first time researchers have demonstrated a device that can take in mixed, or partially coherent, light and sort its photons into a clear set of separate beams.
The finding, published in Nature Photonics, grounds long-theorized physics while unlocking a unique way of observing the world around us, with potential uses in microscopy, astronomy and more fields. "We're experimentally demonstrating stuff that was thought of originally in the 1980s for the first time," said co-lead author Annie Kroo, a Ph.D. student in electrical engineering. "This work has a huge bearing on a whole bunch of different applications because it allows us to think about things in a totally new way." A light bulb is an incoherent light source and a laser is a coherent one, explained Kroo.
Point a laser through a mesh and the light on the opposing surface forms a speckled pattern. Hold a light bulb to the same mesh, and a softer, more diffuse grid emerges. The photons in the laser are all oscillating together, said Kroo, leading to sharper shapes on the wall because in some areas the light adds together and in others it cancels itself out.
The light bulb's photons, by contrast, are bumping around out of sync, leading to a fuzzy pattern. Researchers want to untangle the different rhythms contained in light bulb–style light to enable new types of communication, computing and sensing. "We see a new opportunity in optics, which is to exploit the true nature of light, which is partially coherent, and to use it for various applications," said co-author Charles Roques-Carmes, an assistant professor at the Institute of Science and Technology Austria and former Stanford Science Fellow.
"To do this, you have to decompose it into buckets of light that are mutually incoherent, or statistically uncorrelated." To test this possibility, the team used a photonic chip the size of a fingernail. Photonic chips channel photons for data processing similarly to how the microchips in laptops and cellphones use electrons. While these light-based chips have grown smaller and more powerful in recent years, wrangling the particles inside is still a challenge.
"You can make better optics by putting them on a chip, just like you can make better electronics by putting them on a chip," said co-author Olav Solgaard, the Audrey S. Hancock professor of engineering at Stanford. In their experiment, the researchers pointed two infrared lasers into the chip, mixing the light sources.
Extract — continue reading at the source.
