Dual-level optical single side band modulation scheme for 0.1 tera Hz radio-over-Fiber systems

In this paper, a dual-stage optical single sideband (DSSB) modulation scheme to combat chromatic dispersion for the terahertz wave over fiber (ToF) systems application is proposed. In the scheme, terahertz(THz) wave is obtained via carrier-suppression double sideband modulation, one sideband of terahertz wave then undergo the first single sideband modulation and the second base band SSB modulation in the process of data modulation, which achieves cascade single sideband (SSB) modulation. As can been seen from the simulation result, for mid-frequency carrier of O. ITHz, the BER performance without dispersion compensation achieves 1×10^-11 and the sensitivity of the receiver is -26.6dBm with a data rate of 5Gb/s after 100km transmission. Through comparing the power penalty of double side band (DSB) and DSSB, we demonstrated the optical DSSB modulation has better dispersion tolerance. This paper also shows the contrastive curves of frequency selective fading for the SSB and DSB modulated signals, which definitely demonstrates the existence of dispersion fading during the DSB transmission as well as the effective suppression of the fading implemented by the SSB modulation. The novel scheme's preference is excelled than the conventional scheme's, which is demonstrated by these theory and simulation.