采用高速伪随机码调制和光子计数技术的光纤激光测距系统

在高速伪随机码调制和光子计数技术的激光测距系统中，将1 550 nm光纤激光器的伪随机码调制速率从622 MHz提高到1 GHz，利用光纤延时方法开展了两种调制速率下的测距实验并进行性能验证和对比。采用10阶M序列伪随机码和探测效率为10%的同一个InGaAs/InP雪崩光电二极管，入射到探测器的信号光能量均为1.9410-17 J时，得到二者的系统信噪比基本一致，但在高调制速率下系统的测距精度提高了1.58倍，基本符合理论计算结果。搭建了实际测距平台并开展基于1 GHz调试速率下的室内测距实验，当测量距离约为4.5 m的高反射目标时，得到2.1 cm的测距精度，该实验结果为室外测距实验提供了参考依据。

Laser ranging system based on high speed pseudorandom modulation and photon counting techniques

Pseudorandom modulation rate which used to modulate 1 550 nm fiber laser was prompted from 622 MHz to 1 GHz in the laser ranging system based on high speed pseudorandom modulation and photon counting technology. Ranging performance was compared and demonstrated under two different modulation rates using the optical fiber delay method. 10 order M-sequence pseudorandom code and the same InGaAs/InP single photon detector with detection efficiency of 10% were implemented in the system. Under condition of input signal average energy of 1.9410-17 J, the similar SNRs were acquired in the two systems and the ranging accuracy was improved by 1.58 times under high modulation rate which was in good agreement with theory result. The actual ranging platform was established and ranging experiment was carried out indoor. The ranging accuracy of 2.1 cm was obtained when measuring a high-reflected target which was about 4.5 m away. The result is useful for outdoor ranging system.