Reciprocal phase transition-enabled electro-optic modulation

TL;DR

This paper introduces a novel phase-transition electro-optic modulation mechanism leveraging reciprocal phase plane transitions, achieving ultrahigh efficiency and contrast ratio, demonstrated with a monolithically integrated laser in communication and sensing applications.

Contribution

It reveals a new phase-transition EO modulation mechanism based on reciprocal phase plane transitions, enabling ultrahigh efficiency and contrast ratio in integrated systems.

Findings

Achieved 24.8-GHz RF signal modulation with 3.06 fJ/bit energy efficiency.

Demonstrated over 50 dB contrast ratio in experiments.

Proved effectiveness in radio-over-fibre and underwater sensing systems.

Abstract

Electro-optic (EO) modulation is a well-known and essential topic in the field of communications and sensing. Its ultrahigh efficiency is unprecedentedly desired in the current green and data era. However, dramatically increasing the modulation efficiency is difficult due to the monotonic mapping relationship between the electrical signal and modulated optical signal. Here, a new mechanism termed phase-transition EO modulation is revealed from the reciprocal transition between two distinct phase planes arising from the bifurcation. Remarkably, a monolithically integrated mode-locked laser (MLL) is implemented as a prototype. A 24.8-GHz radio-frequency signal is generated and modulated, achieving a modulation energy efficiency of 3.06 fJ/bit improved by about four orders of magnitude and a contrast ratio exceeding 50 dB. Thus, MLL-based phase-transition EO modulation is characterised by ultrahigh modulation efficiency and ultrahigh contrast ratio, as experimentally proved in radio-over-fibre and underwater acoustic-sensing systems. This phase-transition EO modulation opens a new avenue for green communication and ubiquitous connections.