Ultra-high bandwidth InP IQ modulators for next generation coherent transmitter

We present recently developed ultra-high bandwidth and low V„ InP-based in-phase/quadrature (IQ) modulators that we realized by combining an n-i-p-n heterostructure and a capacitively loaded traveling wave electrode. The extremely low electrical and optical loss structure enhances the 3-dB electro-optic bandwidth of over 67 GHz without degrading other properties such as driving voltage and optical loss. The IQ modulator itself exhibits up to 120-Gbaud rate IQ modulations without optical pre equalization. Furthermore, we examined a low-power dissipation IQ modulator co-assembled with a 495-mW/2ch CMOS differential driver IC, and successfully demonstrated a 64-Gbaud/16QAM operation.