Novel gain control in a multichannel semiconductor optical amplifier with equivalent circuit using nonlinear state-space methods

We develop the first state-space model of a semiconductor optical amplifier that contains nonlinear gain compression and electronic parasitics. The new model adds an equivalent circuit to account for parasitics encountered during electronic SOA control, and polynomial nonlinear gain compression to account for spectral hole burning and carrier heating. Using the model we design a controller that regulates SOA output power by first relating the SOA’s source voltage to its gain, and then driving an optical control channel that keeps the input power constant.