前向糾錯 自發性幅射 拉曼光纖放大器 CS-RZ Carrier-suppressed return to zero RZ-DPSK Return to zero differen-tial-phase-shift keying ETDM Electrical time division multi-plexing OTDM Optical time division multi-plexing OSNR Optical signal to noise ratio PMD Polarization mode dispersion MZM Mach-zehnder modulator FEC Forward error correction EDFA Erbium-doped fiber amplifier ASE Amplified sponta-neous emission FRA Fiber raman amplifier