It is common knowledge that white light is not white but instead a composite of many-colored photons such as red, orange, yellow, green, blue, indigo, violet. Now, researchers at Stanford University have engineered a specialized optical device that allows them to alter the frequencies of each of these individual photons to virtually create any mixture of colors they can imagine.
“This powerful new tool puts a degree of control in the engineer’s hands not previously possible,” Shanhui Fan, a professor of electrical engineering at Stanford and senior author of the paper, said in a statement.
The new innovation features a low-loss wire for light carrying a stream of photons. These photons are generated to enter a series of rings that possess modulators that transform the frequency of the passing photons. Engineers can change the colors exhibited by simply fine-tuning the rings and controlling the modulators.
“Our device is a significant departure from existing methods with a small footprint and yet offering tremendous new engineering flexibility,” Avik Dutt, a post-doctoral scholar in Fan’s lab and second author of the paper, said.
To explain their device, the researchers use the example of an incoming light stream comprised of 20 percent photons in the 500-nanometer range and 80 percent at 510 nanometers. Their invention could fine-tune that ratio to 73 percent at 500 nanometers and 27 percent at 510 nanometers or other combinations of percentages.
The device allows users to achieve any linear transformation that the engineers require, ensuring that a great amount of engineering control is made available.
“It’s very versatile. The engineer can control the frequencies and proportions very accurately and a wide variety of transformations are possible,” Fan added.
The new device has applications in fields ranging from digital communications and artificial intelligence to cutting-edge quantum computing. The research was published in Nature Communication.