自由空间宽谱部分相干光通信系统

Free space optical communication system based on wide-spectrum partially coherent laser

大气湍流对自由空间光通信系统所造成的影响是不可忽略的,为了减弱湍流对空间光通信系统带来的影响,实验搭建了一套通信距离为900m的真实大气信道宽谱部分相干光通信系统。系统采用皮秒脉冲泵浦高非线性光纤产生超连续谱并滤波得到部分相干宽谱脉冲,对其调制后完成通信。在测试过程中,实验专门设置了一条参考链路,保证了测试环境的一致性。实验结果表明,在中等湍流条件下,系统光强闪烁指数为0.035 8,相比窄线宽通信系统提升了23%,最低探测灵敏度达到了-23.35dBm,相比窄线宽通信系统提升了42%。与窄线宽激光通信系统相比,宽谱部分相干光通信系统可以明显降低湍流引起的光功率抖动,并提升自由空间光通信系统通信性能。

The impact of atmospheric turbulence on free space optical communication systems is not negligible.To reduce the influences of atmospheric turbulence on free space systems,a free space optical communication system based on wide-spectrum partially coherent laser in 900 m real atmospheric channel was experimentally demonstrated.The system used a modulated wide-spectrum partial coherence pulsed laser which was filtered from a supercontinuum to communicate,and the supercontinuum was gained by pumping picosecond pulses into a high-nonlinear fiber.In the process of testing,a reference link was set to ensure consistency of the testing environment.The results show that compared to the narrow linewidth communication system,under mid-turbulence condition,the system scintillation index is 0.053 8 which has 23%improvement and the system lowest detection sensitivity is-23.35 dBm which has 42%improvement.The wide-spectrum partially coherent optic communication system can significantly reduce the optical power jitter caused by turbulence and improve the communication performance of free-space optical communication systems.