Storage capacity of slow-light tunable optical buffers based on fiber Brillouin amplifiers for real signal bit streams

Abstract

We present a theoretical analysis of the slow-light tunable optical buffers based on fiber Brillouin amplifiers (FBA). Its storage capacity was discussed for return-to-zero (RZ) and non-return-to-zero (NRZ) bit streams. Gain saturation and pulse broadening are two key factors which limit the buffer capacity. Gain saturation is an inherent characteristic of the FBA. Broadening of the amplified pulse always accumulates with increasing gain owing to the dispersion during stimulated Brillouin scattering (SBS) process. It is shown that the maximum buffer capacity varies with data bit rate and for continuous wave (CW) or quasi-CW pump it is 0.53 and 1.04 bit for RZ and NRZ respectively. Also, the optimum data bit rate to achieve the best storage capacity is obtained.