Synchronous Chaos Generation in an ${\rm Er}^{3+}$-Doped Fiber Laser System

Synchronous chaos generation in an optical fiber laser system that consists of two coupled Er
³⁺
-doped fiber lasers is experimentally analyzed. Using a single amplitude modulator in the system, synchronous chaos generation is obtained at two different modulation frequencies, i.e., 10.38 and 3.85 MHz. The presence of chaotic behavior is verified using FFT spectra and an experimental Lyapunov exponent calculation employing the time series data generated by the fiber laser system. Synchronization between the coupled fiber lasers is demonstrated by the phase diagrams.