Optical computing could benefit from new 'whispering gallery' fiber

It's a spooky feature of Grand Central Station that if you whisper something against the wall, your voice can resonate around the perimeter of the building and sneak up on you from behind. The same 'whispering gallery' principle is crucial to next-gen optical computing: light signals have to be sent on extremely circuitous journeys through 'microresonators', which temporarily bottle up the beams and thereby serve as memory.

So far, microresonators have generally been made from silicon wafers etched with the a long series of loops. However, even the most precise etching leaves imperfections, which quickly cause the signal to lose its strength and fade away. Now, researchers at OFS Laboratories in Somerset, N. J., have come up with a different type of microresonator that could potentially hold onto light 100 times longer.

The new technology diverts light onto a stretch of optic fiber that has been specially manufactured with tiny step-changes in its diameter. When the signal hits this abrupt change, it reverses and goes back the opposite way -- and, if it hits another diameter change, it will effectively enter a whispering gallery inside the fiber, bouncing up and down with only minor attenuation. The OFS scientists claim their microresonator could appear in "specialized devices" in just two or three years, which is good to hear, because electronics is starting to get old.