Transmission of Duobinary Signal in Optical 40 GHz Millimeter-Wave Radio-Over-Fiber Systems Utilizing Dual-Arm LiNbO_3 Mach-Zehnder Modulator for Downstream

摘要

In this paper, for the first time transmission of 2.5 Gb/s duobinary signal is investigated for the downlink direction in 40 GHz optical millimeter-wave generation or up-conversion, utilizing a dual-arm LiNbO_3 Mach-Zehnder modulator based on different modulation schemes, namely double- and single-sideband (DSB and SSB) and optical carrier suppression (OCS). The up-converted optical millimeter-wave employing OCS modulation scheme indicates the highest back-to-back received optical power and the smallest power penalty after long propagation in the single-mode fiber, in comparison to DSB and SSB. Directly modulated laser in association with OCS modulation scheme has been used to generate duobinary optical millimeter-wave signal in order to minimize the cost and complexity of the system.