Linearized Optical Single-Sideband Mach–Zehnder Modulator for Radio-Over-Fiber Systems

We propose and investigate a linearized optical single-sideband (OSSB) Mach-Zehnder modulator (MZM) for radio-over-fiber systems. The linearized MZM makes use of a dual electrode z-cut LiNbO₃ MZM with linear polarizers placed before and after it, respectively. By carefully selecting the angles of the two linear polarizers, third-order intermodulation and second-order distortion can be suppressed significantly. More importantly, it will be shown that with this linearized modulator, not only can OSSB modulation be obtained, but also an improvement in spurious free dynamic range of 15 dB is achieved as compared to the conventional MZM.