GPU-Accelerated Optimisation of Symmetric Bidirectional Ultrawideband Coherent Transmission Under Launch Power Constraints

We optimise bidirectional OESCL-band coherent transmission under total fibre power constraints using a GPU-accelerated boundary-value Raman solver and launch-power optimisation. While no gain is observed without power constraints, for an 18-dBm limit 3-span transmission reversing the O-band direction increases aggregate capacity by up to 24.5%