.Novel transmitter of dark RZ signal based on external modulator[J].Optoelectronics Letters,2007,3(2):109-111 Novel transmitter of dark RZ signal based on external modulator SHAO Yu-feng CHEN Lin WEN Shuang-chun School of Computer and Communication, Hunan University, Changsha 410082, China Abstract:       A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of precoding, modulating and coding. A dark RZ signal is generated simply by using one dual-arm Mach-Zehnder LiNbO3 modulator. We demonstrate experimentally that this optical dark RZ signal can be directly measured by a conventional binary intensity modulation direct detection (IM-DD) receiver. When different values of duty cycles at 2.5 Gbit/s are adjusted, the experimental results show different BER curves and eye diagrams of the optical dark RZ signal. Hits: 3474 Download times: 197 View Full Text    Download reader