Universal Microwave Photonics Approach to Frequency-Coded Quantum Key Distribution

Abstract

Design principles of universal microwave photonics system (MPS) for quantum key distribution (QKD) with frequency coding are concerned. Its main modulation concept lies in single photon generation on sidebands of optical carrier and determination of photons ground state through its registration and the amplitude value of its carrier frequency as reference channel. So, it is necessary to solve problems of signal-to-carrier ratio of single photon detector (SPD) and aspects of photon number splitting (PNS) attack, nonlinear phase modulation (NPM) between carrier and sidebands in fiber, and finally, spectral selection of carrier in receiver. The technologies, based on the modulation conversion of an optical carrier, are widely used in microwave photonics. Due to the natural symmetry of modulated signals and the highest achievable ratio of the modulation conversions, amplitude-phase modulation with complete or partial suppression of the optical carrier has found a particularly wide application in MPS. The characteristics of advanced MPS for QKD with frequency coding and carrier suppression based on tandem amplitude modulation and phase commutation are presented. New systems can have classical symmetric or non-classical asymmetric structure for QKD based only on spectral selection of carrier and subcarriers without re-modulation.

Introductory Chapter: Chromatic Dispersion Monitoring in Synchronization Channel of Quantum Key Distribution Systems with Carrier Modulation Coding

“…In the latter works, to each state of the photons, instead of the amplitude or phase of the modulating signal at a certain frequency, one or more lateral component frequencies either photon optical carrier [9,10] are put into line. We in [11][12][13] present a universal system capable of realizing all the mentioned types of modulation transformation and the new one based on tandem amplitude modulation and phase commutation with partially or full suppressed carrier.…”

“…The main chapter is based on the materials of Morozov et al (2010-2018) papers [11,[15][16][17][18][19][20][21][22] and additional and new results of theoretical and experimental researches in QKD-CMC theme [12,13], so as direct [26] and miscellaneous applications [27][28][29][30]. The next chapter sections are organized as follows.…”