In this work, we propose symmetric nodes for full-duplex plastic optical fiber (POF) communication that utilize a hybrid configuration of distributed Bragg reflector (DBR)-integrated blue-emitting diodes (LEDs) and red LEDs. Due to the light emission and detection capabilities of AlGaInP and InGaN quantum well diodes, the same diode structure can be treated as either a light emitter or a detector, enabling configurable communication links. In the downlink, AlGaInP-based red light chips are placed at the facet ends of the POF. One chip acts as the light emitter, while the other serves as the light receiver. Similarly, the uplink comprises two identical blue light diode chips, integrated within the red link, and incorporates DBR films on the sapphire substrate of the blue LED. A long-pass DBR with a cutoff wavelength of 550 nm is used to block the transmission of backward blue light, significantly reducing crosstalk and enabling the coaxial transmission of both red and blue light links. The system achieves a 10 Mbps pseudorandom binary sequence (PRBS) signal transmission using a red-light link and a 200 kbps PRBS signal transmission using a blue-light link. As a proof of concept, we have successfully demonstrated duplex transmission of a digital audio signal and a digital text signal over a 15 m-long POF.
Shi et al. (Fri,) studied this question.