在由一个外腔分布反馈(DFB)半导体激光器和一个独立的DFB半导体激光器构成的开环单向耦合混沌同步系统中，通过微调发射激光器的偏置电流可以精确控制两个激光器之间的频率失谐，从而可对不同频率失谐下的系统混沌同步状态进行研究。实验研究结果表明，在较小的频率失谐范围(-0.19~0.95 GHz)之内，混沌时间序列在传输延迟时间与外腔反馈时间之差处得到了最大0.84的关联值，而在传输延迟时间处的关联值为0.78。此时，完全同步超越广义同步，系统呈现完全同步状态(CCS)；当频率失谐超过这一范围，广义同步超越完全同步，混沌同步将表现为广义同步状态(GCS)。因此，通过调节发射激光器的电流，可实现完全同步和广义同步之间的转换。理论仿真结果与实验所得结果趋势相同。

In an open-loop unidirectionally coupled chaotic system composed of an external cavity distributed feedback (DFB) semiconductor laser and an isolated DFB semiconductor laser, frequency detuning between two lasers can be controlled accurately by adjusting the bias current of transmitting laser carefully, and then the chaos synchronization state under different frequency detuning values can be investigated. The experimental results show that the system behaves with complete chaos synchronization (CCS) for frequency detuning within a small range (-0.19~0.95 GHz), where the highest correlation value of CCS is 0.84 and the highest correlation value of generalized chaos synchronization (GCS) is 0.78; once the frequency detuning is beyond this range, chaos synchronization will be switched from CCS to GCS. Therefore, synchronization switching between complete synchronization and generalized synchronization can be achieved by adjusting the bias current of transmitting laser. The theoretical simulations exhibit the similar variation tendency as that of the experimental results.