Demonstration of optical frequency quadrupling combined with direct/external signal double-sideband suppressed-carrier modulation

This study experimentally demonstrates the performance of optical frequency quadrupling generation and base-band signal up-conversion techniques based on the cascaded single-electrode Mach–Zehnder modulator (SEMZM) using different signal modulation schemes. The optical signals in microwave band with double-sideband suppressed-carrier (DSB-SC) modulated format exhibit that the receiver sensitivity and the spectral efficiency are maximized and the power penalty over long-distance delivery is minimized. A simple configuration and low-frequency bandwidth requirement for both electrical and optical components in the proposed schemes also are demonstrated.