An improved optoelectronic oscillator scheme for an optical time division multiplexing (OTDM) system based on cascaded Mach-Zehnder modulator (MZM) and polarization modulator (PolM) is experimentally investigated. The system can simultaneously realize clock recovery and demultiplexing. With the MZM working at peak point to generate return-to-zero-33 optical pulses and the PolM working as an equivalent intensity modulator, a high-quality clock signal with 35-fs timing jitter is extracted from the 160-GBaud OTDM-differential quaternary phase-shift keying signal. Narrow short optical switch gates (4 ps) are also generated to demultiplex 160-GBaud signals to 40-GBaud signals. Error-free performance is achieved with 2.4-dB power penalty in the worst case.
© 2013 Chinese Optics Letters
Fiber Optics and Optical Communications
Yu Ji, Xixue Jia, Yan Li, Jian Wu, and Jintong Lin, "Simultaneous clock recovery and demultiplexing of a 320 Gb/s OTDM system using an optoelectronic oscillator based on cascaded MZM and PolM," Chin. Opt. Lett. 11, 050602- (2013)