Abstract : We have experimentally demonstrated the predistortion scheme for linearization of a laser diode which transmits 1.2- and 1.25- GHz RF signal over single-mode fiber. The suppression of intermodulation distortion was achieved by using an additional laser diode to realize the predistorted signals. We have shown a 22.5-dB reduction of the 3rd-order intermodulation distortion and an 11-dB improvement in the spurious-free dynamic range.