The method of chaotic synchronization by coupling drive is proposed for Bragg acousto optic bistable systems, and the condition of chaotic synchronization in two systems is derived by the anylasis of the maximum conditional Lyapunov exponent. It is found that the chaotic outputs of the two systems is synchronized if one system is coupling driven appropriately by another. Numerical results show that this scheme of chaos synchronization resists noise and the synchronization can be realized even if the two systems are not identical. A practical method-non Pecora Carroll′s scheme-of chaotic synchronization is given for delayed differential system with a single variable. Experimental result is presented.