Pioneer announced that they have successfully developed a 16-layer read-only optical disc with a capacity of 400 GB for the first time in the world. The new 400GB disc has the same per-layer capacity of 25GB as the Blu-ray.
“As for the read-out system, Pioneer achieved stability in the playback of recorded signals by employing a wide-range spherical aberration compensator and light-receiving element that can read out weak signals at a high signal-to-noise ratio in the optical pick-up mechanism.”
[Pioneer]