Soliton self-frequency shift (SSFS) is a phenomenon that Raman self-pumping continuously transfers energy from higher frequency components of optical pulse to its lower frequency components. It has been explored over the last decades, because it has many potential applications in the fields of all-optical wavelength conversion, ultra-fast all-optical switch, all-optical de-multiplexing and so on. In this paper, Firstly, using split-step Fourier method for numerical simulation, it has been found that the soliton self-frequency shift increases with the increase of soliton peak power and nonlinear coefficient of the transmission fiber, and decreases with the increase of soliton width and group velocity dispersion. At the same time, third order dispersion is taken into account, which has a significant inhibitory effect on soliton selffrequency shift. Secondly, according to the existing conditions in the laboratory, self-frequency shift in a 2-km-long single-mode fiber has been experimentally studied, especially the influences of soliton peak power and optical fiber dispersion. A continuously tunable self-frequency shift with central wavelength from 4.29 nm to 43.25 nm has been achieved by adjusting the peak power of the soliton. It has been shown that the soliton self-frequency shift can be effectively tuned by flexibly adjusting the related parameters, which provides guidance for many practical applications of soliton self-frequency shift.
In recent years, optical fiber communication system has made a great development, but the quality of the optical signal will be seriously deteriorated by some factors, such as amplified spontaneous emission (ASE) noise, group velocity dispersion and so on. The traditional regeneration technology is accomplished within the electrical domain, and the opticalelectrical-optical conversion consumes vast amounts of energy. So it is necessary for all optical regeneration technology. This paper introduces the principle of an all-optical 2R regenerator based on self-phase modulation(SPM) and offset filtering technology. The deteriorated optical signal at 40 Gbit/s has been regenerated by the combination of SPM in highly nonlinear fiber (HNLF) and offset filtering. The factors influencing the regeneration have been analyzed by changing related parameters. It is concluded that by reasonably choosing parameters, we can get the best result of all-optical 2R regeneration.