We report record 10 Gb/s bi-directional data transmission over a single 10 m SI-POF, by employing blue microlightemitting diodes (μLEDs) at a single wavelength, APD receivers, and a PAM-32 modulation scheme. The implementation of 10 Gb/s LED-POF links takes advantage of the bi-directional configuration, which doubles the overall channel capacity, and APDs, which provide an enhanced link power budget owing to their improved sensitivity compared with conventional p-i-n photodiodes. Moreover, the high spectral efficiency of the PAM-32 modulation scheme employed, together with equalization techniques, enable the full utilization of the link bandwidth and the transmission of data rates higher than those obtained with conventional on-off keying. Simulation and experimental results demonstrate the feasibility of such a bi-directional link, and simultaneous 5 Gb/s data transmission is realized in each direction, achieving an aggregate data rate of 10 Gb/s with a BER < 10 −3 . The crosstalk penalty between the two directions of the link is measured to be less than 0.5 dB.