Pulse shaping for 112 Gbit/s polarization multiplexed 16-QAM signals using a 21 GSa/s DAC Cartledge, John C. ; Downie, John D. ; Hurley, Jason E. ; Karar, Abdullah S. ; Jiang, Ying ; Roberts, Kim Abstract Publication: Optics Express Pub Date: December 2011 DOI: 10.1364/OE.19.00B628 Bibcode: 2011OExpr..19B.628C