This paper describes the design and implementation of wide-band Raman amplifiers for fiber-optic telecommunications systems. All-Raman amplifiers permit 100nm wide systems over spans of over 1500km due to the low noise figure and reduced nonlinear system penalties. 5-dB optical noise figure (NF) over a bandwidth of 102 nm from 1525 to 1627 nm. First, the enabling technologies. We compared the transmission performances of 600 Gbit/s PM-64QAM WDM signals over 75. 6 km of single-mode fibre (SMF) using EDFA, discrete Raman, hybrid Raman/EDFA, and first-order or second-order (dual-order) distributed Raman amplifiers. Our numerical simulations and experimental results showed.