Extraction of signals from chaotic laser data

Several experimental groups have demonstrated communication with chaotic la sers. We analyze data collected from a message-modulated erbium-doped fiber -ring laser (provided by VanWiggeren and Roy). We show that the transmitted signal is dominated by convolution of the message with the response functi on of the laser. A simple model based on the topology of the laser allows u s to recover a hidden message. While prior estimates indicate that the lase r dynamics are high dimensional, we show that only four parameters are requ ired, each of which can be recovered from the transmitted signal alone.