Analysis and Comparative Study of Mainstream Modulation Methods in Optical Communications

Abstract

Optical communication is the core infrastructure underpinning next-generation information technologies including 5G/6G, cloud computing and big data. As the critical link for electro-optical signal conversion in optical communication systems, modulation technology directly determines the system’s transmission rate, capacity and overall cost, and drives the iterative evolution of optical communication systems from 10 Gigabit per second (Gbit/s) to 400 Gbit/s, 800 Gbit/s, and even beyond 1 Terabit per second (Tbit/s). Currently, the optical communication modulation sector features a coexistence of four technical generations. Divergences remain between academia and industry on technical path selection and other core issues, while key bottlenecks like high-order nonlinearity suppression are unbroken, and existing research lacks a systematic review of the field’s technological evolution and core contradictions. Taking modulation technology’s intergenerational evolution as the main line, this paper sorts out the four generations’ core features, analyzes core industry debates, identifies unresolved technical bottlenecks and forecasts development directions. It clarifies the technology’s development context and core contradictions, defines breakthrough directions for ultra-high-speed heterogeneous scenarios, and provides systematic reference and theoretical support for related research, engineering application and industrial deployment.