![Prototype of the satellite-based quantum light source.](https://www.physik.uni-jena.de/pafmedia/182644/quick3-research.jpg?height=428&width=760)
Quantum keys encoded in single photons cannot be easily transmitted over long distances. Due to the no-cloning theorem, it is impossible to copy and amplify the quantum signal. In fibers, the finite absorption and scattering in silica (even at telecom wavelengths) limits the maximum communication distance to a few hundreds of kilometers. Longer distances can be bridged with satellites that can distribute quantum keys with distant optical ground stations around the world.
To develop a satellite that is capable of generating single photon states in orbit, we have miniaturized our single photon source based on a quantum emitter on hexagonal boron nitride. Operating instruments in space environments, however, requires rigorous qualification, including thermal-vacuum cycling, irradiation, as well as mechanical shock and vibration tests. As our payload has passed these tests on the individual component level, we are now integrating the entire system on a 3U CubeSat with the satellite launch scheduled for 2024.
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Selected publications