A 10 GHz high-frequency coupled optoelectronic oscillator for RF/FSO fusion transmission in smoke channels

We proposes and experimentally demonstrates a RF/FSO fusion transmission system under smoke channel. First, an RF and laser-integrated communications payload is designed for RF/FSO fusion links to achieve mutual information backup for both FSO and RF links. Coupled optoelectronic oscillator (COEO) can generate 10.0 GHz low-jitter optical pulses and 10.0 GHz low-phase noise RF signals simultaneously. The measured RF side-mode rejection ratio is 52.16 dB, and the phase noise at 10 kHz offset is about −117.6 dBc/Hz. The experimental results show that COEO has good compatibility in RF/FSO fusion communication and effectively solves the problem of RF/FSO link compatible sharing. Then, we established a RF/FSO fusion transmission system based on a COEO. Taking the complexity of the smoke channel, the RF/FSO link is not switched to achieve simultaneous transmission communication without interruption. The power jitter, signal-to-noise ratio, and bit error rate of RF/FSO links are investigated for different smoke visibility and is further investigated. The experimental results indicate, the fusion RF/FSO system is more reliable under extremely dense smoke conditions based on a COEO, which is significant for the future development of reliable space high-speed information transmission and networking.