Optics Letters

Quantum-enhanced AFDM: a six-dimensional encryption scheme for reliable and secure optical fiber transmission

Jiajia Shen, Suiyao Zhu, Xubiao Zhang, Yifan Ge, Jiamin Fan, Mingyi Gao

Published Oct 10, 2025• 2 citations

Abstract

In this study, we address the challenges of performance and security in passive optical networks (PON) by proposing and experimentally validating a quantum-enhanced affine frequency division multiplexing (AFDM) PON system. Through comparative experimental analysis of chromatic dispersion tolerance characteristics, we demonstrate that AFDM signals achieve receiver sensitivity gains of 0.5 dB, 1 dB, and 3 dB over conventional orthogonal frequency division multiplexing (OFDM) systems in 30-km, 50-km, and 80-km standard single-mode fiber (SSMF) transmissions, respectively. For secure PON transmission, we introduce a six-dimensional (6-D) signal encryption scheme, where the generated random sequence with true randomness masks AFDM signals across multiple physical dimensions to resist brute-force attacks. Experimental validation in a 10-km 7-core fiber system verifies the synergistic integration of multi-core signal distribution and key management, with AFDM exhibiting a 1-dB performance advantage in crosstalk-dominated environments. Notably, the proposed framework demonstrates exceptional inter-core interference suppression while maintaining complete physical layer security, establishing a technological foundation for high-capacity secure optical access networks.

DOI: 10.1364/ol.573632

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