New ultra-wideband 997GHz electro-optic modulator
A new ultra-wideband electro-optic modulator has set a bandwidth record of 997GHz
Recently, a research team in Zurich, Switzerland, has successfully developed an ultra-wideband electro-optic modulator that operates at frequencies ranging from 10 MHz to 1.14 THz, setting a 3 dB bandwidth record at 997 GHz, which is twice the current record. This breakthrough is attributed to the optimized design of plasma modulators, opening up a brand-new space for future terahertz photonic integrated circuits (PICs).
At present, wireless communication mainly relies on microwaves and millimeter waves, but the spectrum resources of these frequency bands have tended to be saturated. Although optical communication has a large bandwidth, it cannot be directly used for wireless transmission in free space. Therefore, THz communication is regarded as the “golden bridge” connecting wireless and fiber-optic networks, providing an ideal solution for 6G and higher-rate communication systems. The problem lies in that the performance of existing electro-optic modulators (such as LiNbO₃ modulator, InGaAs, and silicon-based materials) in the THz frequency band is far from sufficient. The signal attenuation is obvious. The working bandwidth is only about 14 GHz and the maximum carrier frequency is only 100 GHz, which is far from meeting the standards required for THz communication. In this article, researchers have developed a new plasma-based modulator, successfully increasing the 3 dB bandwidth to 997 GHz, which is twice the current record, as shown in Figure 1. This breakthrough not only breaks the limitations of traditional technologies but also broadens the path for the future development of THz communication!
Figure 1 Plasma electro-optic modulator with THz bandwidth
The core breakthrough of this new type of modulator lies in the high-tech called “plasma effect”. Imagine that when light shines on the surface of a metal nanostructure, it resonates with the electrons in the material – the electrons oscillate collectively driven by the light, forming a special kind of wave. It is precisely this fluctuation that enables the modulator to manipulate optical signals with extremely high efficiency. The experimental results show that the modulator exhibits good modulation characteristics within the range of DC (direct current) to 1.14 THz and has stable gain in the frequency band of 500 GHz to 800 GHz.
To deeply study the working mechanism of the modulator, the research team constructed a detailed equivalent circuit model and analyzed the influence of different structural parameters on the performance of the modulator through simulation. The experimental results are in good agreement with the theoretical model, further verifying the efficiency and stability of the modulator. In addition, researchers have proposed an improvement plan. It is expected that through optimized design, the operating frequency of this modulator can exceed 1THz in the future, and even reach over 2THz!
This study demonstrates the great potential of plasma electro-optic modulators in THz communication and photonic integrated circuits (PICs). This device, with its characteristics of ultra-wideband, high efficiency and integrability, provides a brand-new solution for THz signal modulation. In the future, with the further optimization of device design and manufacturing processes, the operating frequency of plasma modulators is expected to exceed 2 THz, achieving higher data rates and wider spectrum coverage. The advent of the THz era not only means faster data transmission and more accurate sensing capabilities, but also will promote the deep integration of multiple fields such as wireless communication, optical computing, and intelligent detection. The breakthrough of plasma electro-optic modulators may become a key step leading the development of THz technology, providing a foundation for the high-speed interconnection of the future information society.
Post time: Jun-09-2025