Quantum communications is quickly becoming integrated within fiber optical networks and still many engineering challenges remain towards this interweaving. This thesis deals with some practical solutions toward improving real-world applications in quantum communications within optical fibers. In the first experiment, a non-degenerate narrowband entangled pair single-photon source based on spontaneous parametric down-conversion (SPDC) is used to show the feasibility of performing quantum key distribution (QKD) through 27 km of optical fiber, with the synchronization channel wavelength multiplexed in the same fiber with a channel spacing of just 0.8 nm. A second experiment uses a heralded single-photon source also based on SPDC to perform QKD over 25 km of optical fiber with the decoy state modification for the first time. Then there is a study of the problems caused by spontaneous Raman induced noise due to the presence of a classical signal in the same fiber as the quantum channel. A protocol to generate truly random numbers in a QKD setup independent of the system s transmission rate is proposed, and a proof-of-principle experiment demonstrates the idea. Finally an automatic polarization control system is used to perform a QKD session over 16 km of optical fiber using polarization encoding, even in the presence of a fast polarization scrambler.