Abstract
The extinction ratio of modulators in quantum key distribution (QKD) transmitters has a significant influence on the quantum bit error rate. In simulations and measurements, we demonstrate that adding an electrically shorted saturable absorber (SA) behind the modulator of a photonic-integrated QKD transmitter chip can increase the extinction ratio of the modulator by up to 10 dB. This paves the way for significantly lower quantum bit error rates when using these transmitters. Because it is shorted, the SA becomes a simple building block, with no need for additional signal inputs. The extra losses in the signal induced by the absorber are irrelevant to the QKD transmitter performance (for both continuous variable and discrete variable QKD transmitters) because the pulses will be attenuated to low photon numbers after the modulation.
| Original language | English |
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| Title of host publication | IEEE Photonics Benelux Chapter Annual Symposium 2024 |
| Subtitle of host publication | Syposium proceedings |
| Number of pages | 4 |
| Publication status | Published - 4 Nov 2024 |
| Event | IEEE Photonics Benelux Chapter Annual Symposium 2024 - University of Twente, Enschede, Netherlands Duration: 4 Nov 2024 → 5 Nov 2024 Conference number: 19 https://photonics-benelux.org/symposium-proceedings/ |
Conference
| Conference | IEEE Photonics Benelux Chapter Annual Symposium 2024 |
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| Country/Territory | Netherlands |
| City | Enschede |
| Period | 4/11/24 → 5/11/24 |
| Internet address |
Funding
This project has received funding from the European Union’s Horizon Europe research and innovation program under the project "Quantum Security Networks Partnership" (QSNP, grant agreement No 101114043). Funded by the European Union. Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.
Keywords
- quantum key distribution
- integrated photonics
- indium phosphide
- integrated qkd transmitter
- saturable absorber