Analysis of Small-Signal Frequency Response of Vertical Cavity Semiconductor Optical Amplifiers

Abstract

Based on the carrier rate equations and the travelling wave equations for the forward and the backward optical fields in vertical cavity semiconductor optical amplifier (VCSOA), a set of differential equations in terms of the perturbations of the optical fields and the carrier density in the cavity are derived by employing the small signal analysis. With the use of these equations, we have investigated the small-signal frequency response characteristics of VCSOA in the saturation region when the input is an amplitude-modulated signal. The results which agree with the reported experimental results show that the VCSOA has high-pass frequency response characteristics.