BOL and EOL OSNR Margins in 10,000 km Pb/s DWDM Unregenerated All-Optical Lightwave Transmission Systems in the 2000 nm Band

We report the calculation of beginning-of-life and end-of-life (EOL) optical signal-to-noise ratio (OSNR) marginsin designs of 10,000 km terrestrial and subsea Pb/s capacity all-optical (without O-E-O regeneration) dense wavelength division multiplexed lightwave systems in the 2000 nm band. Our margin analysis follows the OSNR budget tables originally designed for 1550 nm subsea lightwave transmission systems employing erbium-doped fiber amplifiers, as adapted for novel hybrid Tm-Ho-doped fiber amplifiers and hollow core fibers designed to operate in the 2000 nm region offthe spectrum. Our analysis shows that ideal simulated losses of ≤ 0.0325 dB/km at 2000 nm in the novel hollow core transmission fibers are required for successful EOL system operation in the terrestrial lightwave system design, when assuming that the effective deployed loss = ideal loss + 0.030 dB/km. We discuss the implications of this analysis in the context of terminal tolerances, manufacturing and environmental impairments, Q-factor time variations, customer margins, and the anticipated aging behavior of the novel 2000 nm hollow core transmission fiber. Received: 15 May 2025 | Revised: 29 July 2025 | Accepted: 28 August 2025 Conflicts of Interest The author declares that he has no conflicts of interest to this work. Data Availability Statement Data for the 700 mW 1190 nm fiber-coupled PM-packaged pump diode are openly available at https://www.innolume.com/fabry-perot-laser-diodes/fiber-coupled-single-mode-laser-diode-at-1195nm-5/. Other data are available from the corresponding author upon reasonable request. Author Contribution Statement Robert E. Tench: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Resources, Data curation, Writing – original draft, Writing – review & editing, Visualization, Supervision, Project administration, Funding acquisition.