Challenges and Opportunities in Future High-Capacity Optical Transmission Systems

2. Recent developments in high-capacity transmission systems 2.1 High spectral-efficiency modulation formats and detection schemes 2.2 Orthogonal frequency-division multiplexing 2.3 Recent high-capacity transmission demonstrations 3. Technical challenges in future high-capacity transmission 3.1 OSNR requirements 3.2 Nonlinear fiber impairments 3.3 Linear fiber impairments (including optical amplifier impairments) 3.4 Implementation challenges 4. Estimating a "Shannon limit" for fiber-optic systems 4.1 Historical background 4.2 A capacity estimation framework 4.3 Capacity estimation results 5. Emerging technologies for increasing system capacity and reach 5.1 Novel optical transmission fibers 5.1.1 Ultra-low loss fiber 5.1.2 Large core area fiber 5.1.3 Shorter span length 5.2 Novel optical amplification schemes 5.1.1 Amplification to cover the full fiber transmission band 5.1.2 High-order distributed Raman amplification 5.3 Photonic integrated circuits 5.4 Novel coding techniques 5.5 Compensation of fiber nonlinearity 5.6 Spatial multiplexing 6. Conclusion Acknowledgements Glossary References