We propose a novel digitized radio-over-fiber (DRoF)-based optical video re-transmission system. This system digitally transmits radio frequency (RF) broadcast signals via the communication network (NW) while maintaining the existing RF interface at both ends of the NW by using DRoF technology. Directly digitizing the RF signal makes the required transmission rate of the optical NW impractically large. In order to resolve this issue, we also propose an improved nonlinear quantization (INL) method that combines amplitude clipping and nonlinear quantization. This paper experimentally evaluates the feasibility of optical re-transmission by using a commercial 9-channel multiplexed digital terrestrial television broadcasting signal. The results of the experiment and our theoretical analysis show that it is necessary to re-transmit with 7-bit quantization at the transmitter in order to achieve the required signal quality. However, we show that re-transmission can be realized while satisfying the required quality with just 5 bits by using our proposed INL method. The resulting 2-bit reduction afforded by the INL proposal reduces the transmission rate by 28.6%.