A Voltage Pulse Generator for Measurement-Device-Independent Quantum Key Distribution

Measurement-device-independent quantum key distribution (MDIQKD) protocol has been proven to be unaffected by all hacking attacks and ensures the security of information theory even when the performance of single-photon detectors is not ideal. Single-mode fiber and free space are the two main channel choices in MDIQKD experiments. In this paper, we present a voltage pulse generator (VPG) for the MDIQKD, focusing on the realization of pulse control using a wideband amplifier that offers a high dynamic range, on the prevention of waveform distortion and insufficient drive capacity. In order to implement MDIQKD experiments, either fiber channel or free-space channel, a pulse modulation module is needed to modulate the wide pulse chopping, decoy state, normalization, phase encoding, and time encoding. The test results of the joint test with fiber channel MDIQKD show that the quantum bit error ratio (QBER) in the time state is around 0.034%, and the QBER in the phase state is around 28%. The VPG has fulfilled the requirements of system indicator and has been put into use in actual single-mode fiber channel MDIQKD experiments.