Secure optical communication using stimulated Brillouin scattering in optical fiber

We propose to encrypt/decrypt high-speed optical signal using stimulated Brillouin scattering (SBS) effect in optical fiber for the first time. The broadened SBS gain or loss distorts the amplitude and phase of the optical signal so as to realize all-optical encryption. The corresponding SBS loss or gain with the same bandwidth and amplitude recovers the distorted signal to implement optical decryption. The encryption/decryption keys could be the SBS gain amplitude, bandwidth, central wavelength and the spectral shape, which are configurable and can be flexibly controlled by the users. The operation principle of the SBS based encryption and decryption is explained in detail. Complete encryption and error-free decryption for a 10.86-Gb/s on-off-keying signal has been experimentally demonstrated using broadband SBS amplification and absorption. The immunity of the proposed encryption method to the eavesdropper's attack is also analyzed. The SBS based secure optical communication is compatible with the current optical communication systems.