An efficient optical signal regenerator can mitigate the effect of signal degradation and increase the performance of optical communication system. All optical signal regenerators have been studied and developed for maintaining good quality signal in long haul optical communication. Fiber nonlinearity has some inherent properties for signal regeneration and it has an enormous potential for ultra-high speed optical communication. In this paper, all optical signal regeneration techniques using self-phase modulation (SPM) are examined. Major drawbacks of the existing regenerators have also been identified.