Experimental Analysis of Laser Phase Noise Tolerance of Uniform 256QAM and Probabilistically Shaped 1024QAM

We experimentally compare laser linewidth tolerance of US-256QAM and PS-1024QAM. US-256QAM has higher achievable information rate (AIR) with <5% pilot symbol and 40 kHz linewidth, while PS-1024QAM realizes higher AIR than US-256QAM with narrower linewidth.