Phase-resolved measurement and control of ultrafast dynamics in terahertz electronic oscillators

TL;DR

This paper demonstrates a photonic technique to measure and control ultrafast phase dynamics in terahertz electronic oscillators, crucial for future wireless communication technologies like 6G.

Contribution

It introduces a femtosecond laser-based method for phase-resolved, sub-cycle measurement of THz oscillators, surpassing electronic bandwidth limitations.

Findings

Observation of anti-phase locking behavior in THz oscillators

Verification that dynamics follow universal synchronization theory

Enabling precise phase control for high-speed wireless applications

Abstract

As a key component for next-generation wireless communications (6G and beyond), terahertz (THz) electronic oscillators are being actively developed. Precise and dynamic phase control of ultrafast THz waveforms is essential for high-speed beam steering and high-capacity data transmission. However, measurement of such ultrafast dynamic process is beyond the scope of electronics due to the limited bandwidth of the electrical measuring instruments. Here we surpass this limit by applying photonic technology. Using a femtosecond laser, we generate offset-free THz pulses to phase-lock the electronic oscillators based on a resonant tunneling diode. This enables us to perform phase-resolved measurement of the emitted THz electric field waveform in time-domain with sub-cycle time resolution. Ultrafast dynamic response such as anti-phase locking behaviour is observed, which is distinct from in-phase stimulated emission observed in laser oscillators. We also show that the dynamics follows the universal synchronization theory for limit cycle oscillators. This provides a basic guideline for dynamic phase control of THz electronic oscillators, enabling many key performance indicators to be achieved in the new era of 6G and beyond.