Abstract In this paper, we present a cascaded system, with optical intensity chaos and electro-optic phase chaos, to allow for bidirectional communication. In this scheme, we utilize the intensity chaotic signal instead of the traditional continuous wave (CW) to inject into the electro-optic oscillator to produce a phase chaotic signal. Under a suitable feedback intensity, we also demonstrate that the configuration can generate the chaos with high complexity and high dimension by using largest Lyapunov exponents (LLEs) and Lempel–Ziv Complexity (LZC). Using the delay time identification techniques, we show that the configuration can successfully conceal all time delay signatures (TDSs), which correspond to the feedback delays of both laser and electro-optic oscillator. By mutually phase modulating between two output signals at both oscillators, delay dynamics is induced in both sides. We numerically demonstrate that this dynamics can be identically synchronized. Based on the synchronization between transmitter and receiver, the messages introduced at two ends of the link can be simultaneously exchanged. We still find that: under a little mismatch of parameter, the system can maintain good quality of transmission. This scheme provides a possible way to achieve chaotic bidirectional confidential communication.

中文翻译：

---

光强与相位反馈相结合的混沌保密通信系统时延特征隐藏

摘要 在本文中，我们提出了一个具有光强度混沌和电光相位混沌的级联系统，以实现双向通信。在该方案中，我们利用强度混沌信号代替传统的连续波（CW）注入电光振荡器以产生相位混沌信号。在合适的反馈强度下，我们还证明了该配置可以通过使用最大李雅普诺夫指数（LLE）和 Lempel-Ziv 复杂度（LZC）产生高复杂度和高维的混沌。使用延迟时间识别技术，我们表明该配置可以成功隐藏所有时间延迟特征 (TDS)，这对应于激光和电光振荡器的反馈延迟。通过在两个振荡器的两个输出信号之间相互相位调制，双方都诱发了延迟动态。我们在数值上证明了这种动力学可以完全同步。基于发送器和接收器之间的同步，链路两端引入的消息可以同时交换。我们仍然发现：在参数稍微不匹配的情况下，系统可以保持良好的传输质量。该方案提供了一种实现混沌双向保密通信的可能途径。