Stabilized Dispersion-Robust Millimeter-Wave Anything-Over-Fiber Transmitter in Access Networks Featuring a Double Sideband Suppressed Carrier Modulation

In this paper we address the instability of a dispersion-resistant anything-over-fiber (AoF) transmitter with frequency doubling. This technology supports the evolution of higher-radio-frequency (RF) telecommunication systems operating in the millimeter-wave (mmW) range. The use of mmW communications has also gained attention in the area of optical access networks due to the increasing demand for higher data-transmission rates and the apparent spectrum congestion. However, the transmission of mmW signals over fiber-optic networks presents challenges related to the signal degradation caused by chromatic dispersion. In this paper a power-penalty-free transmission in the mmW range is enabled by an optical double-sideband transmitter with a suppressed carrier (ODSB-SC) based on a Mach-Zehnder-modulator (MZM). Due to its susceptibility to volatile operating conditions, the intended
$U_{\pi}$
bias voltage varies over time. Therefore, we propose a purely analog, closed-loop-control (CLC) system that continuously adjusts the bias voltage to provide the maximum suppression of the optical carrier at the MZM's output. We demonstrate experimentally the feasibility and performance of our proposed, stabilized, dispersion-robust mmW AoF transmitter. The results highlight the system's ability to achieve stable, dispersion-free mmW transmission over extended fiber links, making it a promising solution for next-generation access networks.