Modeling and Experimental Measurement of Power Efficiency for Power-Limited SDM Submarine Transmission Systems

Power efficiency of long-haul optical fiber transmission has emerged as a critical challenge to cost-effectively increasing submarine cable capacity. Building on previous experimental work and informed by physical system modeling and optimization, we report on extensive amplified transmission experiments characterizing the metric of fiber capacity per unit pump power over a range of amplifier powers and link distances relevant to power-limited spatial-division-multiplexed submarine systems. We compare experimental results with modeling incorporating optical amplifier physics as well as generalized droop, demonstrating excellent agreement over the range of powers and distances tested. We predict the performance gains achievable by further optimizing the system design and implementation within tolerances ideally achieved in deployed submarine systems, and estimate fiber pair counts and total cable capacities achievable for the link distances investigated. Our results suggest the utility of amplifier pump powers as low as 20 mW and output powers as low as 6.5 dBm in reaching Pb/s cable capacities.