High-efficiency WDM-ROF system based on the technology of generating tunable OFC by cascading EAM and FM

The rapid growth of diverse service demands and the limited spectrum resources pose challenges to traditional wireless communication systems. Combining optical communication with radio-over-fiber (RoF) and wavelength division multiplexing (WDM) technologies offers a promising solution for high-capacity scenarios. The existing optical frequency comb (OFC) as a WDM light source has the potential to significantly enhance the capacity and flexibility of RoF systems. However, the OFC generation schemes have issues such as high complexity, poor flatness, and limited scalability. This paper proposes a new OFC generation technology based on the cascade of an electro-absorption modulator (EAM) and a frequency modulator (FM),and explores the influence of parameters such as the center frequency of the light source, the line width of the light source, the working parameters of EAM, the amplitude of the FM driving signal and the phase difference of the modulator driving signal on the performance of OFC generation. The generated OFC is used as multiwavelength carriers in the WDM-RoF system. The proposed optical frequency comb (OFC) can adjust the number and spacing of spectral lines, with a bandwidth of 615 GHz and a flatness of 0.68 dB for the central 16 lines. The WDM-RoF system supports 16-channel multiplexing, with a transmission distance of up to 70 kilometers and a bit error rate (BER) of only 10^-9. This solution provides a cost-effective and scalable option for high-bandwidth scenarios such as urban areas and transportation hubs.