中文摘要：

设计了与125Mbps聚合物光纤局域网兼容的自由空间光通信系统，以实现楼宇间的数据通信，克服聚合物光纤传输距离较短的缺点．自由空间光通信包括发射和接收两个部分，发射部分由650nm半导体激光器，驱动电路和准直扩束镜组成，接收部分由接收透镜和光电探测器组成．半导体激光器的调制发射功率为3dBm，光电探测器的探测灵敏度为-27dBm．分析了大气对光信号的衰减阱及大气湍流造成的光斑抖动对通信的影响，记录了系统的信号传输波形和通信眼图。实验表明，自由空间光通信可以延长聚合物光纤局域网的通信距离，使其在实际工程中的应用更加灵活．

英文摘要：

A free space optical （FSO） communication system was designed, which is compatible with 125Mbps polymer optical fiber （POF） LAN system. The FSO system realizes multibuilding communication and extends the transmission distance of POF LAN. The system includes emission and receiving part. The emission part is composed of a 650 nm laser diode （LD）, a drive circus and beam alignment and expand lens. The receiving part is composed of a receiving lens and a photo detector （PD）. The modulated emission power of LD is 3 dBm and the sensitivity of PD is -27dBm. The atmosphere attenuation to 650 nm light and the dot whipping caused by air turbulence were analyzed. The signal transmission waveform and communication eye diagram of the system were recorded. The experiment shows that the transmission distance of POF LAN was extended by FSO, which enables more flexibility of the POF LAN installation.