Noise in sliced self-phase modulation broadened spectrum

Summary form only given.Recently there has been a great interest in applications where a slice of a broad optical spectrum generated by nonlinear effects in a fiber is filtered out by selecting a narrow part of the spectrum with an optical filter. When operating in anomalous dispersion regime in the fiber, the filtered pulses become noisy if the input pulses are not extremely stable in amplitude and the signal to noise ratio (SNR) is very high. This is due to unstable excitation of higher order solitons either due to amplitude fluctuations in the input pulse itself or due to beating between the pulse and optical noise, e.g., from an erbium-doped fiber amplifier (EDFA). This phenomenon has been shown to become a severe limitation in the generation of super continuum where the input peak power has to be extremely high compared to the generation of a fundamental soliton. In this communication we show that this effect also has severe noise implications even at the much lower input power required for moderate SPM broadening of the spectrum. Here, the growth of noise is characterized by measuring the SNR versus input power for a sliced SPM broadened spectrum. Random generation of higher order solitons, when pumping the fiber in the anomalous dispersion regime, may also impair other all optical fiber devices, like the nonlinear optical loop mirror and devices relying on four wave mixing.