New technology achieves data transmission speeds of up to 100 Gbps with minimal signal loss; breakthrough could enable compact, low-loss terahertz circuits

 

THEBUSINESSBYTES BUREAU

NEW DELHI, NOVEMBER 4, 2026

In a significant breakthrough that could accelerate the development of next-generation wireless communication, Indian researchers have developed a novel silicon chip that allows terahertz waves to pass through engineered barriers with remarkably little signal loss while supporting data transmission speeds of up to 100 gigabits per second (Gbps).

The innovation, developed by a research team at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, could pave the way for compact, high-speed terahertz circuits for future sixth-generation (6G) wireless networks.

Terahertz frequencies, which lie between microwaves and infrared light, are considered promising for 6G communication because of their ability to support exceptionally wide bandwidths and faster data transmission. However, guiding these waves through compact circuits has remained a major technological challenge, as bends, junctions and physical obstacles can scatter or reflect signals, resulting in transmission losses.

Addressing this challenge, the researchers employed an approach based on topological photonics, arranging triangular holes in a carefully engineered pattern on a silicon slab to create a photonic crystal. The structure, which mimics the honeycomb lattice of graphene, enables terahertz waves to travel along the boundary between two regions while resisting certain forms of signal backscattering.

The team demonstrated that the waves could cross deliberately introduced barriers created by modifying the sizes of triangular holes in the silicon structure, without significantly compromising signal transmission.

Measurements showed that a single barrier introduced only around 1-2 per cent signal loss, while two barriers placed sequentially resulted in a loss of approximately 2-3 per cent. In contrast, a conventional waveguide without the topological design experiences a substantial reduction in transmission when confronted with a comparable obstacle.

The researchers further established that transmission remained close to its barrier-free level as long as the barrier strength remained below a characteristic coupling strength of the photonic crystal, offering a practical design principle for developing such devices.

To validate the technology, the team fabricated three devices using high-resistivity silicon, a material compatible with established semiconductor manufacturing processes. These included a device featuring two successive barriers, an omega-shaped waveguide incorporating four sharp bends and a central barrier, and a power splitter with a barrier introduced in one of its two branches.

Tests conducted across frequencies ranging from 310 to 360 gigahertz showed close agreement between experimental measurements and computer simulations. The power splitter also delivered nearly identical signals through its two output branches, indicating that the engineered barrier had little impact on transmission.

In high-speed communication experiments, the double-barrier and omega-shaped devices achieved data rates of 48 Gbps and 60 Gbps, respectively. More significantly, the power splitter supported transmission at 100 Gbps using QAM-32 modulation, a technique that encodes information through variations in a signal's amplitude and phase.

At this speed, a five-gigabyte high-definition film could theoretically be transferred in less than half a second, highlighting the potential of the technology for future ultra-high-speed communication systems.

The study was led by Dr Abhishek Kumar, Assistant Professor at JNCASR and head of its Meta Optics Laboratory (MetoLab). Samina Mulla and Sangram Kumar Sadhu of JNCASR were the joint first authors.

The international collaboration involved researchers from JNCASR, IISER Kolkata, IIT Bombay, the Institute of Microelectronics at A*STAR in Singapore, and the University of Lille and CNRS in France.

"Showing that terahertz waves can cross a barrier created simply by changing the hole geometry, while carrying 100 gigabits per second, suggests that this effect can become a useful design tool for terahertz chips," Dr Kumar said.

The findings, published in the journal Advanced Materials, could help scientists develop integrated terahertz circuits capable of routing and splitting signals on a single chip with minimal losses.

The researchers are now exploring ways to control the barriers electrically, thermally or mechanically. Such capabilities could eventually allow terahertz chips to dynamically redirect signals between different pathways, opening up new possibilities for flexible and energy-efficient communication hardware for future 6G networks.