In this dissertation, it is depicted short optical pulses generation with different repetition rates, for soliton based transmission systems applications. In order to accomplish that, a fiber laser operating at the third window of the optical communication (1.55 um) was developed, capable of generate short pulses, through the active mode-locking technique. Within the current configuration, the Mach-Zehnder modulator, usually employed, was replaced by a DFB laser, running as both an intensity modulator and tunable optical filter. The semiconductor laser was gain switched through direct modulation, leading the cavity to operate on harmonic mode- locking scheme. A continuous wavelength tuning could be achieved by changing the temperature of the diode laser. Several aspects were analyzed, such as stability, duration and spectral purity of the optical pulses generated by this source. The wavelength tuning range and its possible repetition rates were also investigated. The optical pulses were transmitted through standard optical fiber links, demonstrating the propagation of solitons.