Demonstration of a 100  Gb/s complex-valued double-sideband direct-detection PON with a 42/49  dB optical power budget over a 20  km SSMF/AR-HCF

In passive optical networks (PONs), the optical power budget serves as a key determinant of system scalability. A higher power budget allows for larger split ratios over a given transmission medium, thereby enabling more end users to share the same infrastructure and reducing the cost per subscriber. In this paper, we introduce a carrier-assisted complex-valued double-sideband direct detection PON architecture that eliminates the need for a local oscillator laser at the optical network unit of coherent PON while maintaining a high optical power budget. The system leverages a deep-learning-enabled optimal direct-detection receiver to achieve high launch power and receiver sensitivity without the complexity of coherent detection. Using the proposed architecture, we experimentally demonstrate an optical power budget of 42 dB for 100 Gb/s downstream transmission over 20 km standard single-mode fiber (SSMF), meeting the 15% soft-decision forward error correction (SD-FEC) threshold of 2×10 −2 . To the best of our knowledge, this represents the highest optical power budget for a 100 Gb/s direct-detection PON using SSMF. Furthermore, by employing our self-developed 20 km anti-resonant hollow-core fiber, we demonstrate an optical power budget of 49 dB under the 15% SD-FEC threshold, marking a record-high optical power budget achieved to date for 100 Gb/s PON.