Researchers at the Institute of Photonics have developed a transmitter-receiver concept that enables the transmission of entangled photons over optical fibers. This is a key step toward building a quantum Internet. The team successfully maintained photon entanglement when combined with a laser pulse.
This allows simultaneous transmission of conventional and quantum data through the same color channel. It overcomes previous limitations. This breakthrough could pave the way for hybrid networks.
Optical fibers can support both conventional and quantum Internet. It ensures that all color channels remain available for traditional data transmission. In their experiment, the researchers demonstrated that the entanglement of photons is maintained even when they are sent together with a laser pulse.
The researchers at Leibniz University Hannover’s Institute of Photonics have developed a method to change the color of a laser pulse. They use a high-speed electrical signal to match the color of the entangled photons. This enables the researchers to launch both laser pulses and entangled photons of the same color into an optical fiber.
They can then separate them after transmission. “To make the quantum Internet a reality, we need to transmit entangled photons via fiber optic networks,” says Prof. Dr. Michael Kues.
Photon entanglement in hybrid networks
He is the Head of the Institute of Photonics and Board Member of the PhoenixD Cluster of Excellence at Leibniz University Hannover. “We also want to continue using optical fibers for conventional data transmission.
Our research is an important step to combine the conventional Internet with the quantum Internet.”
The four researchers involved in the study are Jan Heine, Philip Rübeling, Michael Kues, and Robert Johanning. Philip Rübeling explains, “We can change the color of a laser pulse with a high-speed electrical signal so that it matches the color of the entangled photons. This enables us to combine laser pulses and entangled photons of the same color in an optical fiber and separate them again.”
This innovation could integrate the conventional Internet with the quantum Internet.
It allows both transmission methods to use the same color channels in an optical fiber. Until now, entangled photons blocked a data channel in the optical fiber. This prevented its use for conventional data transmission.
With this new concept, photons can now be sent in the same color channel as the laser light. This implies that all color channels could still be used for conventional data transmission. “Our experiment shows how the practical implementation of hybrid networks can succeed,” says Prof.
Michael Kues. This research represents a significant step towards the development of a quantum Internet. It provides secure communication channels that could be virtually eavesdropping-proof.
The research results were published in a leading scientific journal.
