Performance Improvement of Optical Single Sideband Signal Using an Integrated Mach-Zehnder Modulator

Abstract

A novel integrated Mach-Zehnder modulator consisting of three phase modulators to generate an optical single sideband with carrier signals in the radio-over-fiber system has been proposed. By adjusting the direct current voltage applied in the modulation arm, named the “direct current arm,” the power of the optical carrier in the optical single sideband signal is controllable, and the optimal carrier-to-sideband ratio of 0 dB can be achieved for any modulation index. The simulation results show that the receiver sensitivity can be greatly improved, and the radio-over-fiber system based on the proposed technique has better robustness.