Silicon-organic hybrid (SOH) Mach-Zehnder modulators for 100 GBd PAM4 signaling with sub-1 dB phase-shifter loss
Clemens Kieninger, Christoph Füllner, Heiner Zwickel, Y. Kutuvantavida, J. N. Kemal, Carsten Eschenbaum, Delwin L. Elder, Larry R. Dalton, W. Freude, Sebastian Randel, C. Koos
Abstract
We report on compact and efficient silicon-organic hybrid (SOH) Mach-Zehnder modulators (MZM) with low phase-shifter insertion loss of 0.7 dB. The 280 µm-long phase shifters feature a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi>π</mml:mi> </mml:mrow> </mml:math> -voltage-length product of 0.41 Vmm and a loss-efficiency product as small as aU π L = 1.0 VdB. The device performance is demonstrated in a data transmission experiment, where we generate on-off-keying (OOK) and four-level pulse-amplitude modulation (PAM4) signals at symbol rates of 100 GBd, resulting in line rates of up to 200 Gbit/s. Bit error ratios are below the threshold for hard-decision forward error correction (HD-FEC) with 7% coding overhead, leading to net data rates of 187 Gbit/s. This is the highest PAM4 data rate ever achieved for a sub-1 mm silicon photonic MZM.