D-Band MUTC Photodiode Module for Ultra-Wideband 160 Gbps Photonics-Assisted Fiber-THz Integrated Communication System

Abstract

Current wireless communication systems are increasingly constrained by insufficient bandwidth and limited power output, impeding the achievement of ultra-high-speed data transmission. The terahertz (THz) range offers greater bandwidth, but it also imposes higher requirements on broadband and high-power devices. In this work, a modified uni-traveling-carrier photodiode (MUTC-PD) module with WR-6 waveguide output is presented for photonics-assisted fiber-THz integrated wireless communications. Through the optimization of the epitaxial structure and high-impedance coplanar waveguide (CPW), the fabricated 6 µm-diameter MUTC-PD achieves a high output power of −0.96 dBm at 150 GHz and ultra-flat frequency response at D-band. The MUTC-PD is subsequently packaged into a compact WR-6 module, incorporating planar-circuit-based RF-choke, DC-block, and probe. The packaged PD module demonstrates high saturation power and flat frequency responses with minimal power roll-off of only ≈2 dB over 110–170 GHz. By incorporating the PD module into a fiber-THz integrated communication system, the high data rate of up to 160 Gbps with 16 quadrature amplitude modulation (QAM) is successfully secured. The demonstration verifies the potential of the PD module for ultra-broadband and ultra-high-speed THz communications, setting a foundation for future research in high-speed data transmission.