| Robustness of fiber-optic attenuators to 1061-nm sub-nanosecond pulsed laser radiation in quantum key distribution systems
System
- Daria Ruzhitskaya, Irina Zhluktova, Anastasiya Ponosova, Fedor Ushakov, Andrey Zverev, Galina Tertyshnikova, Tianyi Xing, Kirill Min'kov, Daniil Trefilov, Anqi Huang, Vladimir Kamynin, Vladimir Tsvetkov, Vadim Makarov
- 2026
Abstract
Sub-nanosecond pulsed laser radiation at 1061 nm (average power up to about 1 W) is shown to permanently damage fibre-optic attenuators used in QKD sources, lowering the optical damage threshold relative to continuous-wave exposure. MEMS-based variable optical attenuators show an irreversible attenuation reduction of about 3.8 dB and fixed absorptive attenuators up to 7 dB, inflating the transmitter mean photon number above its calibrated value.