Advance opens door for secure quantum applications without specialized infrastructure
This is a cool progress forward.
TLDR; Researchers used a 30km optical fiber. They found a wavelength that was off-to-the-side that would mean the quantum entangled photons could ride in the same fiber without interfering (or being interfered with) the classical fiber optic communications. One current shortcoming for scaling this up is that the quantum photons would not survive optical repeaters commonly used for extremely long distant fiber runs. That doesn’t take away from the success of their research, just puts it in perspective for the next researchers to tackle at some point in the future.
Is the reason (Im assuming you ment) it can’t survive a repeater survive a repeater because it collects and recreates the particle? These cables are ment for logical data transport.
Yes. Keep in mind nothing in the article talks about the fiber repeater. That is my addition with some knowledge of telecommunications infrastructure. Because fiber optic cable isn’t perfect, there is light loss over distance. Different grades of fiber have different levels of loss across distance. An example of high end fiber would be ZBLAN. There is experimental level manufacturing (successful in small quantities already) of producing ZBLAN fiber in space to improve the fiber quality, but that makes it much more expensive. Once the limits of the fiber are reached a telecommunications provider can place a fiber repeater to double the length by intercepting the light (signal) and reproducing it (blinking new laser light) into the next segment of fiber.
However, these repeaters create NEW light, and that would mean the quantum information is not carried over in present day fiber repeaters. Even measuring the entangled photon to recreate it would break the quantum state of the entangled photon at the source, so current means can’t be used as a repeater for quantum data.
