Theoretical analysis of carrier heating effect in semiconductor optical amplifiers

This paper reports an accurate and simple analytical method to study carrier heating effect in semiconductor optical amplifiers (SOAs) using both Fermi-Dirac integrals of 3/2 and 1/2 orders. Global approximations for Fermi-Dirac integrals of 3/2 and 1/2 orders are adopted to obtain the analytical expression for the carrier temperature The amplification of a single strong pico-second pulse having different peak powers is studied both with and without carrier heating effect. It has been found carrier heating impose more distortion on the amplified pulse, including suppressing the peak power value, increasing the peak temporal shift and broadening the bandwidth of amplified output signals. Also, when the input signal peak power or the pump current increases because of carrier heating effect the carrier temperature increases too. We have studied the amplification of 80Gbit/s pico-second pulse sequences and found an increase in the peak value of the amplified output signal due to the pronounced fast gain recovery process induced by the carrier heating effect.