Title :
42.7-Gb/s cost-effective duobinary optical transmitter using a commercial 10-Gb/s Mach-Zehnder modulator with optical filtering
Author :
Gill, Douglas M. ; Gnauck, Alan H. ; Liu, Xiang ; Wei, Xing ; Levy, David S. ; Chandrasekhar, S. ; Doerr, Christopher R.
Author_Institution :
Lucent Technol. Bell Labs., Murray Hill, NJ, USA
fDate :
4/1/2005 12:00:00 AM
Abstract :
Optical duobinary transmission at 42.7 Gb/s is demonstrated using a commercially available 10-Gb/s LiNbO3 modulator. The intrinsic response of the 10-Gb/s electrooptic Mach-Zehnder modulator (MZM) is used to create a low-pass-filtered (LPF) duobinary signal, which shows a minimum optical signal-to-noise ratio (OSNR) requirement penalty of ∼4 to ∼6 dB as compared to nonreturn-to-zero (NRZ) signals. However, when the MZM-LPF duobinary is filtered with a 50-GHz 3-dB bandwidth first-order Gaussian filter, a significant improvement in required OSNR is seen. In contrast, similar optical filtering of NRZ data creates a significant OSNR penalty such that the NRZ and MZM-LPF duobinary data have nearly identical OSNR requirements. Therefore, the MZM-LPF duobinary technique may be a cost-effective approach to high-spectral-efficiency transmission at 42.7 Gb/s.
Keywords :
electro-optical modulation; lithium compounds; low-pass filters; optical fibre communication; optical filters; optical transmitters; 10 Gbit/s; 42.7 Gbit/s; 50 GHz; LiNbO3 modulator; LiNbO3; duobinary optical transmitter; electrooptic Mach-Zehnder modulator; first-order Gaussian filter; low-pass-filtered duobinary signal; nonreturn-to-zero signals; optical filtering; optical signal-to-noise-ratio penalty; Bandwidth; Costs; Filtering; Optical fiber filters; Optical filters; Optical modulation; Optical noise; Optical signal processing; Optical transmitters; Signal to noise ratio; Duobinary transmission; modulation coding; modulators; optical fiber communication;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2005.843931
