High-density optical fiber arrays would offer more, and thinner, probes for neuronal exploration than bulky electrodes.

CNN: Brain map seeks to unlock mysteries of the mind

At the time there were two high density optical storage formats being developed.

BBC: NEWS | Technology | Q&A: Death of a format

As we learned when the console was initially announced, the Wii U's "proprietary high-density optical discs" hold up to 25GB of data -- equivalent with that of Sony's single-layer Blu-ray format on the PlayStation 3, and much larger than the Xbox 360's dual-layer DVD format.

ENGADGET: Take a very, very close look at the round-edged Wii U proprietary discs