Ultra-fast, high-power MUTC Photodiodes with bandwidth-efficiency product over 130 GHz * 100%

TL;DR

This paper presents a novel InP-based MUTC photodiode with over 200 GHz bandwidth and a high bandwidth-efficiency product, enabling ultra-fast, energy-efficient wireless communication at sub-terahertz frequencies.

Contribution

The work introduces a waveguide-integrated MUTC photodiode with optimized design achieving record-breaking bandwidth-efficiency product over 130 GHz * 100%, surpassing previous limits.

Findings

Achieved 206 GHz 3-dB bandwidth and 0.8 A/W responsivity.

Delivered RF power over -5 dBm from 127 to 185 GHz.

Demonstrated 120 Gbps wireless data transmission over 54 meters.

Abstract

The accelerating demand for wireless communication necessitates wideband, energy-efficient photonic sub-terahertz (sub-THz) sources to enable ultra-fast data transfer. However, as critical components for THz photonic mixing, photodiodes (PDs) face a fundamental trade-off between quantum efficiency and bandwidth, presenting a major obstacle to achieving high-speed performance with high optoelectronic conversion efficiency. Here, we overcome this challenge by demonstrating an InP-based, waveguide-integrated modified uni-traveling carrier photodiode (MUTC-PD) with a terahertz bandwidth exceeding 200 GHz and a bandwidth-efficiency product (BEP) surpassing 130 GHz * 100%. Through the integration of a spot-size converter (SSC) to enhance external responsivity, alongside optimized electric field distribution, balanced carrier transport, and minimized parasitic capacitance, the device achieves a 3-dB bandwidth of 206 GHz and an external responsivity of 0.8 A/W, setting a new benchmark for BEP. Packaged with WR-5.1 waveguide output, it delivers radio-frequency (RF) power exceeding -5 dBm across the 127-185 GHz frequency range. As a proof of concept, we achieved a wireless transmission of 54 meters with a single-line rate of up to 120 Gbps, leveraging photonics-aided technology without requiring a low-noise amplifier (LNA). This work establishes a pathway to significantly enhance optical power budgets and reduce energy consumption, presenting a transformative step toward high-bandwidth, high-efficiency sub-THz communication systems and next-generation wireless networks.