This paper presents an equivalent lumped element electric circuit model for traveling wave semiconductor optical amplifier (SOA) in integrated circuit applications. The model facilitates incorporation of chip and package parasitic elements of SOA. The model is used to represent an all optical 2 × 2 switch based on cross gain modulation in SOA capable of operating at an ultra fast speed. SPICE simulation of the switch with the proposed circuit model provides bit error rate (BER) values at the switch output which agrees well with the experimentally measured values at 10 Gb/s. The degradation of switching performance has been examined in terms of bit error rate, modulation bandwidth and switching time in the presence of chip parasitic elements of SOA. © 2010 Springer Science+Business Media, LLC.