Train communication system using graded-index leaky plastic optical fiber

We propose a new train communication system using optical wireless communication. In the proposed system, graded-index (GI) leaky plastic optical fiber (POF) is used as the communication medium. Since this fiber has the structure where scatterers are mixed in the core of normal GI-POF, the light which is entered through the end of this fiber from laser diode (LD) can be leaked along the fiber. This GI leaky POF and a photo detector are installed in train and the ground, and the light which leaks from this fiber is received continuously by a photo detector. From the measurement results, we confirmed that new GI leaky POF has the broadband and low delay characteristics The experimental results show that this new train communication method using a leaky optical fiber is a very promising technology for the future high-speed data communication between trains and a ground.