Design of a Novel 31.5 THz Bandwidth Hybrid TDFA-HDFA at 2000 nm and Its Applications in Unregenerated DWDM Lightwave Transmission Systems

We report the design and applications of a novel multi-Watt (>1Watt output power) 2000 nm band hybrid Thulium- and Holmium-doped fiber amplifier with record wideband 380 nm (31. 5 THz) continuously operating bandwidth from 1720 to 2100 nm. We outline the theory, physics, and simulations behind this design and show by comparison with previously published experimental results that the design presented is accurate to within ±0. 5 dB in saturated output power and ±1. 0 dB in small signal gain. Applications in future ∼300–400 nm bandwidth wideband 2000 nm Pb/s DWDM lightwave fiber optical transmission systems spanning 10, 000 km using new hollow-core fiber designs are discussed. In particular, we demonstrate robust beginning-of-life optical signal-to-noise ratio and Q-factor margins for designs of 0. 161 Pb/s DWDM unregenerated (without optical-to-electrical-to-optical or O-E-O electronic functions) all-optical transmission in the 2000 nm band over 10, 000 km for representative terrestrial and submarine lightwave applications. We achieve a total capacity × distance product of 1608 Pb/s. km (1. 61 Exabits/s. km) over a single one-core optical fiber for the 10, 000 km system designs. Applications to designs of 40, 000 km deployable unregenerated all-optical DWDM 0. 124 Pb/s subsea lightwave transmission systems with 5. 21 Exabit/s. km capacity × distance product are outlined. Received: 9 September 2024 | Revised: 10 December 2024 | Accepted: 26 December 2024 Conflicts of Interest The author declares that he has no conflicts of interest to this work. Data Availability Statement Exail Tm- and Ho-doped gain fiber specifications are openly available at https: //cybel-llc. com/wp-content/uploads/2021/06/IXF-HDF-PM-8-125ₑdA-Ho-SC-doped-PM-fiber. pdf and https: //cybel-llc. com/wp-content/uploads/2021/06/IXF-TDF-PM-5-125ₑdA-Tm-SC-doped-PM-fiber. pdf. Data of the component devices in Table 1 are openly available at https: //retandassociatesllc. com/wp-content/uploads/2024/04/GSLEOP2022-Presentation-RET-v. 11-08222022. pdf. 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.