Digital linearization techniques are proposed to compensate the inherent nonlinearity of radio over fiber (ROF) links. In respect to the characteristic of ROF links, which have centralized control units and simple remote access units, multi-dimensional digital predistortion for multi-band ROF downlinks is proposed. The maximum input Radio frequency (RF) power increase 3 dB, indicating the improvement of downlink power efficiency. A memory-free multi-dimensional digital predistorter involving nonlinearity orders up to 5 at twice of oversampling rate is presented for practical multi band ROF links. For uplinks, the linearization technique is proposed based on the acquisition of output third-order intercept point. The spurious-free dynamic range (SFDR) of 128.3 dB in 1 Hz bandwidth is achieved by using the technique. A digital post-compensation technique based on blind estimation is proposed to linearize multi-band ROF uplinks, which gives the improvement of 3 dB dynamic range.