光轨(LT)是一种新型光通信网络结构，具有交换粒度小、带宽利用率高等优点。目前对光轨网络节点结构研究很少，尤其缺乏光轨节点性能仿真和实验研究。鉴于此，设计了一种支持4波长双向通信的光轨网络节点结构；搭建了光轨通信系统仿真平台，对单个光轨节点的光功率损耗，以及联网条件下数据波长的误码率和眼图进行了仿真测试。仿真测试结果显示，单个光轨节点的光功率损耗约16 dB，未配置光放大器时，适用于节点间距小于20 km的光轨网络；配置单个半导体光放大器后，可将节点间距增加5 km。针对节点间距15 km和20 km，系统误码率分别降低了105和102，眼图质量明显改善。该光轨节点具有结构简单、成本低、损耗低的优点，能够满足城域/接入光通信网络的传输要求。

Light trail (LT), a novel optical network, promises small switching granularity and good bandwidth utilization. There is little research on LT node until now, especially on its performance simulation and experimental demonstration. A novel LT node architecture that supports 4 wavelengths for duplex communication is introduced. And a simulation platform is built to test the performance of the LT node, including insertion loss as well as bit error rate (BER) and eye diagram in LT networking. The simulation shows that its insertion loss is about 16 dB, which means that it should work at intervals of less than 20 km if without help of semiconductor optical amplifiers (SOAs). Further simulation shows that a single SOA can be employed to improve eye diagram, increase work distance of 5 km, and decline BER about 105 at 15 km distance or 102 at 20 km. Finally the conclusion can be drawn that the reported LT node has the advantages of simple structure, low cost and low loss, and is suitable for application in metropolitan and access optical networks.