Extraction of signals from chaotic laser data

Several experimental groups have demonstrated communication with chaotic lasers. 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 function of the laser. A simple model based on the topology of the laser allows us to recover a hidden message. While prior estimates indicate that the laser dynamics are high dimensional, we show that only four parameters are required, each of which can be recovered from the transmitted signal alone.