S-band gain flattened distributed fiber Raman amplifier with chirped fiber bragg grating filter

S-band gain flattened distributed fiber Raman amplifier with a bandwidth from 1 488 nm to 1 541 nm (53 nm in width), an averaged gain of 10 dB and a gain ripple of ±0.6 dB is obtained successfully, in which a single-wavelength high power fiber Raman laser with wavelength of 1 427.2 nm is used as the pump and the chirped fiber Bragg grating is used as the gain flattening filter. Besides, filter wavelength division multiplexer (FWDM) is used as the multi-signal multiplexer and 1 427 nm/1 505 nm coarse wavelength division multiplexer (CWDM) is used as the pump-signal coupler. The gain media are G652 fiber of 50 km in length and dispersion compensation fiber (DCF) of 5 km in length. Moreover, the location arrangements of different type of fibers and the effect caused by gain flattening filter as well as their solutions are discussed in detail. It is very significant to extend the range of optical fiber communication band and increase the capacity of fiber communication especially for ultra-long haul and ultra-high capacity communication system.