arXiv subjects

A. V. Losev

Publications and source records attributed to A. V. Losev.

4 recordsLinked to original sources

arXiv2022

Dead time duration and active reset influence on the afterpulse probability of InGaAs/InP single-photon avalanche diodes

We have performed a detailed study of the dependence of afterpulse probability in InGaAs/InP sine-gated SPAD on the dead time and the existing approach for its implementation. We demonstrated an electrical scheme combining sinusoidal gating and active reset. We have shown when such solutions are beneficial from the key distribution point of view and enough to use a simple scheme with a snatching comparator. We have also proposed a precise method for measuring the afterpulse and presented a model describing the non-markovian dynamic of this effect. We have demonstrated that our afterpulsing measurement approach makes these measurements less dependent on the parameters of the flow of the diode and the laser pulses power changes, in contrast to the other methods considered in this paper.

quant-ph↗

arXiv2021

Investigation of the dependence of noise characteristics of SPAD on the gate parameters in sine-wave gated single-photon detectors

In this paper, we have investigated a self-developed sine wave gated (SWG) single-photon detector (SPD) for 1550 nm wavelength primary for quantum key distribution (QKD) usage. We have investigated different gate parameters` influence on the SPD`s noise characteristics. We have admitted that with an increase of gating voltage and constant value of quantum efficiency (QE), the dark count rate (DCR) decreases. There have been made some recommendations to improve SPD`s and whole QKD device's characteristics based on these observations. There have been discovered the quick rise of the DCR value with the increase of gating voltage above some certain value and this value was different for different detectors. It has been shown that universal empirical dependence compilation to connect control and operational parameters of SPD is a non-trivial task.

quant-ph↗

arXiv2019

Modular quantum key distribution setup for research and development applications

Quantum key distribution (QKD), ensuring the unconditional security of information, attracts a significant deal of interest. An important task is to design QKD systems as a platform for education as well as for research and development applications and fast prototyping new QKD protocols. Here we present a modular QKD setup driven by National Instruments (NI) cards with open source LabView code, open source Python code for post-processing procedures, and open source protocol for external applications. An important feature of the developed apparatus is its flexibility offering possibilities to modify optical schemes and verify novel QKD protocols. Another distinctive feature of the developed setup is the implementation of the decoy-state protocol, which is a standard tool for secure long-distance quantum communications. By testing the plug-and-play scheme realizing BB84 and decoy-state BB84 QKD protocols, we demonstrate that developed QKD setup shows a high degree of robustness beyond laboratory conditions. We demonstrate the results of the use of the developed modular setup for urban QKD experiments.

quant-ph↗

arXiv2018

Educational potential of quantum cryptography and its experimental modular realization

The fundamental principles of quantum mechanics are considered to be hard for understanding by unprepared listeners, many attempts of its popularization turned out to be either difficult to grasp or incorrect. We propose quantum cryptography as a very effective tool for quantum physics introduction as it has the desired property set to intrigue students and outline the basic quantum principles. A modular desktop quantum cryptography setup that can be used for both educational and research purposes is presented. The carried out laboratory and field tests demonstrated usability and reliability of the developed system.

physics.ed-ph↗