In this paper, we have evaluated a bidirectional wavelength division multiplexing passive optical network (WDM-PON) employing intensity modulated/direct detection optical orthogonal frequency division multiplexing (IM/DD-OFDM). The proposed system employs 100 Gbit/s 16 quadrature amplitude modulation (16-QAM) downstream and 5 Gbit/s on-off keying (OOK) upstream wavelengths, respectively. The proposed system is considered low-cost as non-coherent IM/DD OFDM technology and a simple reflective semiconductor optical amplifier (RSOA) colorless transmitter are employed and no dispersion compensating fiber (DCF) is needed. Based on the bit error rate (BER) results of WDM signals, the proposed WDM-PON system can achieve up to 1.6 Tbit/s (100 Gbit/s/λ × 16 wavelengths) downstream transmission over a 30 km single mode fiber (SMF).