Researchers at Leibniz University Hannover have achieved a groundbreaking milestone in telecommunications. For the first time, they successfully transmitted entangled photons alongside laser pulses of the same colour over a single optical fibre. This innovation, spearheaded by four researchers from the Institute of Photonics, paves the way for the integration of conventional and quantum internet.

Figure 1. Optical Fibres.

Figure 1 shows optical fibres. Prof. Dr. Michael Kues, head of the Institute of Photonics, emphasized the significance of this advancement: "To make the quantum internet a reality, we need to transmit entangled photons via fibre optic networks. We also want to continue using optical fibres for conventional data transmission. Our research is an important step to combine the conventional internet with the quantum internet." [1, 3]

The experiment demonstrated that entangled photons remain intact even when transmitted with a laser pulse. Philip Rübeling, a doctoral student at the Institute of Photonics, explained, [2] "We can change the colour of a laser pulse with a high-speed electrical signal so that it matches the colour of the entangled photons. This effect enables us to combine laser pulses and entangled photons of the same colour in an optical fibre and separate them again."

This technological leap allows for the simultaneous use of both transmission methods per colour in an optical fibre, overcoming previous limitations where entangled photons blocked data channels. Jan Heine, another doctoral student in Kues's group, noted the significance: "The entangled photons block a data channel in the optical fibre, preventing its use for conventional data transmission."

Prof. Michael Kues highlighted the practical implications: “Our experiment shows how the practical implementation of hybrid networks can succeed.” The research findings, published in Science Advances, mark a critical step towards realizing a secure, eavesdropping-proof quantum internet.

Source: Leibniz University Hannover

References:

1. https://www.sciencedaily.com/releases/2024/08/240805134133.htm
2. https://phys.org/news/2024-08-physicists-method-combine-conventional-internet.html
3. https://www.eurekalert.org/news-releases/1053570

Cite this article:

Hana M (2024), Entangled Photons and Laser Pulses Share a Single Optical Fibre, AnaTechmaz, pp. 151