100 GHz RoF system based on two free running lasers and non-coherent receiver

A 100 GHz radio over fiber (RoF) system based on two free running distributed feed back (DFB) lasers at the transmitter and a non-coherent receiver is proposed and experimentally demonstrated. Different modulation techniques such as QPSK, 16QAM and OOK for the data rate of more than 1 Gbps have been demonstrated for this RoF system. At the central station, one of the two modes is intensity modulated using external modulator and then the two modes propagate through single mode fiber to the base station. The millimeter wave at 100 GHz is produced by heterodyning of two optical modes at a pin photo-diode. At the receiver, an envelope detector (ED) has been used in order to down-convert data to intermediate frequency (IF). The experimental results show that the impact of phase and frequency instability of the system based on two free running lasers on Error Vector Magnitude (EVM) for the communication system based on non-coherent detection is completely vanished.