Capacity-Approaching Modulation Formats for Optical Transmission Systems: Signal shaping and advanced de/muxing for efficient resource exploitation.

Aiming for efficient fiber-optic data transport, this thesis addresses three scenario-specific modulation and/or multiplexing techniques which, leveraging digital signal processing, can further exploit the available resources.The considered environments are: (i) (ultra) long-haul networks, where we focus on improving the receiver sensitivity; (ii) metropolitan area networks, where the target is providing spectral and rate adaptability with fine granularity and easy reconfigurability; and (iii) short-haul networks, where facilitating more affordable throughput scaling is pursued. Functioning essentials, signal attributes, and digital processing structures are discussed in detail; whereby we give grounds for their adoption into the respective contexts of the three proposed systems. Eventually, we conduct the corresponding experimental validations; overall proving their potential. The reported results encourage the continuation of the research, mainly towards algorithm refinement.