Design and Fabrication of Mixed Electronics-Optics Modulator for Dual-Carrier QPSK Generation

We discuss in detail the design and fabrication of a mixed electronics-optics (MEO) modulator and related key devices. Our proposed MEO modulator generates dual-carrier quadrature phase-shift keying (QPSK) signals utilizing both analog electrical and optical modulation with a simple optical circuit configuration. The key devices for the MEO modulator include a high-speed electrical-phase modulator and a complex optical modulator. We report the design and fabrication of a high-speed phase modulator IC with 0.5-μm InP HBT technology, and a silica-LiNbO
₃
integrated optical amplitude and phase modulator. We performed proof-of-concept experiments for the MEO modulator, and confirmed the generation of 26-GHz spacing 14-GBaud dual-carrier QPSK signals.