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Updated: Dec 27, 2025

Generation and Coherent Control of Pulsed Quantum Frequency Combs
Published on: June 8, 2018
A 5 GHz and 7.5 V multi-amplitude modulator driving circuit for practical high-speed quantum key distribution
Xiang Liu1, Ming-Qi Huang1, Hao Min1
1Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
Abstract:
Quantum key distribution (QKD) offers the ability of information theoretic security key exchange. The secure key rate is an important indicator for the practical QKD systems, which determines what kinds of applications can be supported. One most effective way to enhance the secure key rate is to increase the system repetition frequency. Here, we report an implementation of a high-speed DC-coupled modulator driving circuit with a repetition rate of up to 5 GHz. The circuit outputs a multi-amplitude return-to-zero pattern pulse with a maximum amplitude of 7.5 V. The design adapts to the various electro-optic modulators widely employed in QKD systems. The minimum pulse width is measured as 75 ps, with the relative noise level less than 1.5% for all the output amplitudes under random modulation.
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