Japanese-Led Team Achieves 1.02 Petabit-Per-Second Data Transmission Over 1,808 km

An international research team led by Japan’s National Institute of Information and Communications Technology (NICT) has demonstrated a data transmission rate of 1.02 petabits per second across 1,808 kilometres of optical fibre — a result that sounds almost unimaginable by today’s consumer internet standards.

The achievement was made using a specially developed 19-core optical fibre with a standard 0.125 mm cladding diameter. According to NICT, the experiment marked the first successful petabit-class transmission over more than 1,000 km using this type of standard-diameter 19-core fibre.

How Fast Is 1.02 Petabits Per Second?

One petabit equals 1,000 trillion bits. NICT said 1.02 petabits per second is roughly 26 times the total download traffic generated by subscribers to Japan’s fixed broadband internet services as of November 2024. The figure describes the capacity achieved in an experimental optical-fibre transmission system, not a home broadband connection or a single consumer download.

The Technology Behind the Record

The team used a 19-core fibre developed by Sumitomo Electric Industries. Instead of carrying information through only one core, the fibre uses 19 cores within a standard-sized cladding. The researchers also developed a system capable of amplifying signals across all 19 cores and used digital signal processing to remove interference between them.

180 Wavelengths Carry the Data

The experimental system transmitted signals using 180 wavelengths across the C and L optical bands. The signals travelled repeatedly through an 86.1 km fibre loop until the researchers reached a total transmission distance of 1,808 km. The combined data rate across all wavelength channels reached 1.02 petabits per second.

Why the Distance Matters

Ultra-high speeds have been demonstrated in optical-fibre laboratories before, but maintaining enormous capacity across long distances is a separate challenge. NICT reported a capacity-distance product of 1.86 exabits per second-kilometre, which it described as a world record for standard-cladding-diameter optical fibres at the time the result was presented.

Could This Become Your Home Internet Speed?

Not anytime soon. The demonstration was a research experiment involving specialised multicore fibre, optical amplifiers, multiple wavelengths and advanced signal processing. Its importance lies in showing how future backbone networks and links between major cities could carry vastly more data as demand from cloud computing, AI, streaming, next-generation mobile networks and other digital services continues to grow.

A Step Toward Future Communications Infrastructure

The results were presented at the Optical Fiber Communication Conference (OFC 2025) in San Francisco and accepted as a post-deadline paper. Researchers say further work will focus on improving optical amplification efficiency, optimising digital signal processing and exploring practical applications of the technology.

Source: National Institute of Information and Communications Technology (NICT), Japan; OFC 2025 research announcement.