连续散射分布式光反馈产生无延时特征的宽带混沌激光

Chaotic light has broad application prospects in many areas, especially chaotic secure communications and high-speed random number generation. Chaotic light is typically generated by semiconductor lasers subject to optical feedback because of its simple structure. However, the generated chaotic signals are obviously characteristic of the delay induced by the external cavity. The delay characteristics can degrade the security of chaotic optical communications and the randomness of fast random numbers. At present, the delay characteristics are suppressed mainly through adjusting feedback strength and injection current of semiconductor lasers to certain special values. But for this method, adjustment of control parameters is difficult, its suppression mechanism is unclear, and whether the delay characteristics are successfully eliminated or not remains up in the air..The project proposes a generation method of broadband chaotic laser signals with no delay characteristics. A continuous scatterer is utilized as a distributed feedback external cavity of a semiconductor laser, and the delay characteristics of chaotic signals are eliminated by random perturbations of continuous scattering feedback light on the semiconductor laser. The project will establish a theoretical model of broadband chaotic laser source with no delay characteristics to know how chaotic laser signals are generated, and finally experimentally achieve a broadband chaotic light source with no delay characteristics..The successful implementation of this project will develop a novel chaotic light source that combines two sorts of technology, i.e., the broadband chaotic laser generation and the delay characteristics elimination, and promote the advance of chaotic light application technology.

混沌激光在混沌保密通信和高速随机数产生等领域具有广阔应用前景。混沌激光产生的典型方式是利用结构简单的光反馈半导体激光器实现。然而，产生的混沌激光信号具有明显的反馈延时特征，降低了混沌光通信的保密性和高速随机数的随机性。目前抑制延时特征的方法，主要是通过调节半导体激光器的偏置电流和反馈强度在某些特定值下抑制延时特征。但这种方法调节困难，机理尚不明确，能否成功消除延时特征仍存在异议。.本项目提出一种无延时特征宽带混沌激光产生方法。利用连续散射体作为半导体激光器的分布式反馈外腔，通过连续散射的反馈光无规律的扰动半导体激光器，从而消除混沌激光的延时特征。本项目拟建立无延时特征宽带混沌激光源的理论模型，探明无延时特征混沌信号的产生机理，最终实验实现无延时特征的宽带混沌激光源。.本项目的实施将有望发展一种新型的宽带混沌激光产生和延时特征消除直接融合的混沌激光源，可进一步推动混沌激光应用技术的发展。

混沌激光在高速真随机数产生、激光雷达、光纤传感等领域具有重要应用，但结构简单的光反馈半导体激光器产生的混沌激光信号会含有外腔延时特征，这严重地限制了混沌激光的应用。本项目采用单模光纤、啁啾光纤光栅、光波导、Fabry-Perot滤波器等分别作为半导体激光器的反馈器件，都成功抑制了混沌激光的延时特征。利用对两个外腔半导体激光器输出信号的光外差作用，实现了对混沌激光延时特征的抑制。利用光电振荡器产生了无延时特征的宽带混沌激光。提出一种检测延时特征的新方法，利用频谱放大法对上述方案中混沌激光信号的延时特征的抑制进行了验证。上述相关研究成果已获得2014年度山西省科学技术奖（自然科学类）二等奖。.此外，还探讨了无延时特征混沌激光信号在高速真随机数的产生、超宽带雷达系统、激光雷达、光纤传感等方面的应用。实现了码率为4.5Gbps真随机数的产生。实现了24km长、距离分辨率为3cm的单、双目标的远程探测。在自由空间中实现距离分辨率为18cm、探测距离为130m的目标探测。基于布里渊光纤激光器传感系统实现了温度分辨率为3.104MHz/℃的温度传感；.总之，本项目申请国家发明专利9项，其中已经授权3项，公开6项。发表（录用）期刊学术论文27篇，其中被SCI收录18篇。参加会议和光电展览会16次，作会议报告5次。培养研究生10名。本项目对混沌激光信号延时特征的成功抑制，将极大地推动并优化混沌激光的应用。