提出一种基于半导体光纤环形激光器的混沌光纤围栏系统。在该系统中,激光器输出为具有帧结构的偏振混沌光,环形激光器中的一段光纤用作传感光纤。任意位置的入侵都会改变光纤的双折射分布状态,引起环形激光器初始状态的改变,由于混沌对初值的敏感性,激光器输出波形即刻被改变。通过相邻帧输出波形的互相关检测可实现入侵的检测。利用混沌环形激光器输出波形的帧型特点实现入侵定位的空间时间转换。利用入侵位置与帧间互相关峰值的对应关系实现入侵的定位。该方法实时性好,抗干扰性强,检测结果不受周围环境变化影响。实验结果表明,在3 km左右的监测范围内定位误差约45 m,相对误差5%,且检测结果重复性良好。

A chaotic fiber fence system based on a semiconductor fiber ring laser is proposed,in which the laser outputs are framing polarization chaotic light and a part of the fiber ring is taken as sensing fiber. Wherever the intrusion acts in the sensing fiber,it will disturb the distribution state of the birefringence in the fiber,which influences the initial state of the laser. Output waveform changes immediately because chaos is sensitive to its initial value. By a cross-correlation detection of the waveforms in adjacent two frames,the intrusion can be detected. The position of the ring can be converted to the time of the frame with the framing characteristic of the chaotic waveform. According to the relation between the intrusion position and cross-correlation peak value,the intrusion position is located. This method is real time and with stronger anti-interference capacity and the detection results are immune from external environment fluctuations. The experiment results illustrated that the system has a location error of about 45 m,the relative error of 5%,and a good repetitiveness with a 3 km long sensing fiber.