Title :
Synchronization Monitoring of I/Q Data and Pulse Carving Misalignment for a Parallel-Type RZ-DQPSK Transmitter by Measuring RF Clock Tone/Low Frequency Power
Author :
Wu, Xiaoxia ; Christen, Louis ; Zhang, Bo ; Peng, Wei-Ren ; Yang, Jeng-Yuan ; Zhang, Lin ; Nuccio, Scott R. ; Paraschis, Loukas ; Jargon, Jeffrey A. ; Willner, Alan
Author_Institution :
Dept. of Electr. Eng., Univ. of Southern California, Los Angeles, CA
Abstract :
We experimentally demonstrate a technique for monitoring the time misalignment of in-phase/quadrature (I/Q) data streams and pulse carver/data in a 20-Gb/s return-to-zero differential quadrature phase-shift-keying (RZ-DQPSK) transmitter. By measuring the radio-frequency clock-tone power at 10 GHz and low frequency power at 600 MHz, a monitoring power dynamic range of 18 dB is obtained for I/Q data misalignment and 6 dB is shown for carver/data misalignment. With the monitor information, a simple feedback loop is proposed to automatically align the RZ-DQPSK transmitter.
Keywords :
differential phase shift keying; optical feedback; optical fibre communication; optical modulation; optical transmitters; synchronisation; bit rate 20 Gbit/s; feedback loop; fiber-optics communications; frequency 10 GHz; frequency 600 MHz; in-phase/quadrature data streams; pulse carving misalignment; radio-frequency clock-tone power; radio-frequency low frequency power; return-to-zero differential quadrature phase-shift-keying transmitter; synchronization monitoring; Fiber-optics communications; return-to-zero differential quadrature phase-shift-keying (RZ-DQPSK);
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2008.2007503
