Phys.org May 10, 2023
Temporal modes (TMs), an encoding basis based on the time-frequency degree of freedom of photons, represent one of the most promising high-dimensional alphabets. TM-based quantum communication has until now been limited to a two-dimensional space due to the lack of a suitable decoder. However, quantum communication protocols based on single-photon TMs require suitable multichannel decoders. Researchers in Germany have demonstrated a new device that facilitates demultiplexing of high-dimensional TMs of single photons, and implemented a complete five-dimensional decoder that enables TM-based high-dimensional quantum key distribution. They showed that it is possible to scale the presented decoder scheme to even higher dimensions. They implemented a multi-output quantum pulse gate, a newly developed integrated device that enabled high-dimensional decoding of TMs of single photons, thereby unlocked the benefits of high-dimensional TM encoding. They also demonstrated that the multi-output quantum pulse gate is an intrinsically scalable system that, for the first time, enabled time demultiplexing of high-dimensional TMs and therefore represents a breakthrough in quantum communications and beyond… read more. Open Access TECHNICAL ARTICLEÂ
The working principle of the MQPG… Credit: PRX Quantum 4, 020306 – Published 12 April 2023Â