DAC-Free Ultralow-Power Dual-Polarization 64-QAM Transmission at 32 GBd With Hybrid InP IQ SEMZM and BiCMOS Drivers Module

A hybrid transmitter module comprising a 15-segment InP IQ segmented Mach–Zehnder modulator and two 0.13
μ
m BiCMOS SiGe:C drivers with integrated 4-bit DAC functionality is described. The high-resolution prototype allows a wide range of modulation formats and, for the first time, ultralow-power dual-polarization (DP) 64-QAM signal generation at record speed of 32 GBd without the usage of external DACs is demonstrated. The DP 64-QAM signal is transmitted error free over 80 km of SSMF with 7.8 pJ/bit/polarization energy consumption. Post-FEC BER results are presented, with more than 2
²⁶
bits decoded without errors after four decoding iterations. The package footprint is 28 mm × 76 mm. These results evidence the advantage of the proposed arrangement for the next generation low-power high-speed optical transceivers.