Standard fiber achieves a world record for bandwidth, surpassing total global internet traffic

A research team from the Network Research Institute of Japan's National Institute of Information and Communications Technology (NICT) has achieved a new world bandwidth record of 1.53 Pbit/s on a standard-diameter optical fiber. This means that the entire global internet traffic can fit within it.
A similar breakthrough was reported two weeks ago: a bandwidth of 1.84 Pbit/s was achieved with a single laser and a single optical chip, a value higher than that achieved by ICTs, but the problem is that it is still experimental. Photonic chips are in the design stage; therefore, this ICT research could be implemented sooner.

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Multiplexing technology: achieve a record bandwidth of 1.53 Pbit/s
The researchers achieved a bandwidth of approximately 1.53 Pbit/s by encoding the information across 55 different optical frequencies (a technique known as multiplexing). That's enough bandwidth to carry all of the world's internet traffic (estimated at less than 1 Pbit/s) through a single fiber optic cable—a million times more effective than the gigabit connection (at best) that the average person has.
The technology works by harnessing different light frequencies across the spectrum. Since each "color" in the spectrum (visible and invisible) has its own frequency, unlike all other frequencies, it can carry its own independent stream of information. The researchers achieved a spectral efficiency of 332 bits/s/Hz (bits per second per Hertz), three times higher than their previous best attempt in 2019, which achieved a spectral efficiency of 105 bits/s/Hz.

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Experimental setup: C-band information transmission at 184 different wavelengths
The researchers successfully transmitted C-band information across 184 different wavelengths: these independent, non-overlapping frequencies are used to transmit information simultaneously within the fiber optic cable. The light is modulated to transmit 55 separate streams (patterns) of data before being sent through the fiber optic cable. Once modulated (like most fiber optic cables currently deployed), it requires a glass core to carry all the data. As the data (spanning 184 wavelengths and 55 modes) is sent, the receiver decodes the different wavelengths and modes to collect its data. In the experiment, the distance between the transmitter and receiver was fixed at 25.9 km.

① Optical comb source: 184 carriers are generated in an optical comb source. ② Signal modulation: The carrier is modulated with 16 QAM signals and multiplexed polarization. ③ Parallel signal generation: The signals for each mode are split, and path delays are applied to simulate independent data streams. ④ Mode multiplexer: Each signal is converted into a different spatial mode and sent to a 55-mode fiber. ⑤ 55-mode fiber: The signal propagates in a 25.9-kilometer-long 55-mode fiber. ⑥ Mode demultiplexer: At the receiver, the signal is separated into each spatial mode and converted to the fundamental mode. ⑦ High-speed parallel receiver: The mode-demultiplexed signal is wavelength-demultiplexed by a filter and converted into an electrical signal by a parallel coherent receiver. ⑧ Offline signal processing. MIMO processing to eliminate signal interference during fiber propagation.

Experimental results show that although the data rate drops slightly at the long wavelength end of the C band (around 1565 nm), a stable and nearly uniform data rate is obtained in other wavelength regions, reaching a total of 1.53 Pbit/s after error correction.