Japan breaks world internet speed record ⏩⏺️
Japan’s researchers at the National Institute of Information and Communications Technology (NICT) have obliterated previous records—first hitting 319 Tbps in 2021, and more recently soaring to an astounding 402 Tbps in mid‑2025, all using standard single‑mode optical fibers .
🚄 How they achieved 402 Tbps
1. **Full-spectrum multiplexing across six bands (O, E, S, C, L, U)**
They transmitted a massive 37.6 THz of bandwidth by using all low-loss silica fiber bands—not just the typical C/L used in telecom .
2. **Dense Wavelength Division Multiplexing (DWDM)**
The fiber carried around 1,505 separate wavelength channels, splitting data into ultrafine slices via comb lasers .
3. Multi-core fiber usage
They used a fiber with 4 cores, enabling parallel data streams, combining Space-Division Multiplexing (SDM) with WDM .
4. Advanced amplification tech
Transmission spanned 50 km using six types of doped‑fiber amplifiers (Erbium, Thulium, etc.) along with Raman amplification—boosting multiple wavelength bands simultaneously .
🕓What’s next?
Though it’ll take time before your home connection reaches these speeds, expect:
⏺️Upgrades to backbone and undersea links using these techs.
⏺️New amplifier and terminal systems to support broader spectrum use.
⏺️R&D in routers and storage to handle the data deluge.
🌬️Japan didn’t just break a record—they opened a pathway for hyperspeed internet using the fibers already around us.
