To effectively reduce the cost of optical access network

a wavelength reused Mode-Division-Multiplexing（MDM）scheme for bidirectional optical access network with low mode-crosstalk Multiplexer/Demultiplexer（MUX/DEMUX）and Few Mode Fiber（FMF）is proposed.In downstream（DS）transmission

one of the spatial modes in FMF is used to transmit optical carrier while the others are used as DS signal channels.In upstream（US）transmission

the carrier is split to all the ONUs for US re-modulation.By utilizing mode MUX/DEMUX with low mode crosstalk and FMF

the carrier and each signal channel can be effectively separated.Moreover

to reduce the bidirectional Rayleigh backscattering noise

different optical sidebands for DS and US transmission are proposed.With the proposed scheme

symmetrical bidirectional 2×12.5 Gbit/s Quadrature Phase Shift Keying（QPSK）Orthogonal Frequency Division Multiplexing（OFDM）Intensity Modulation and Direct Detection（IMDD）transmission over 11.5 km 4-mode FMF is experimentally demonstrated.